My September 2017 visit to GP Gliders [Archive]

jfitch

November 2nd 17, 06:00 AM

On Tuesday, October 31, 2017 at 3:29:13 PM UTC-7, wrote:
> Your question: How much will they be asking for the GP 15 JETA self launcher?
>
> My answer: I may be the wrong person to answer, but I can tell you several facts about my purchase five months ago. The base price for the JETA was 93,900 USD.
>
> This included the standard Galaxy BRS rescue system and the 25KW Rotex electric motor with MGM COMPRO speed controller. My trailer's base price was 14,900 USD. The trailer was optional; I heard from a fellow USA customer that he chose to go Cobra.
>
> There are many options on both the glider and the trailer. I wanted to discuss avionics with them but now understand that it is too early to choose. My guess is that by the time I get to include the options, my JETA's price will be around 130,000 USD, or more (it will be fabric seats for me instead of leather) between now and then, there will likely be many changes to the options list. For example, the factory is trying to decide which way to go with the tail wheel: fixed, retractable, and/or steerable.
>
> And what I really like is that the Technical Consultant wants maximum speed.
>
> On YouTube you can google GP Gliders. As a future owner, my favorite video is the one with Sebastian Kawa talking about the GP-14 just before the 2017 WGC. Recognizing that he could win, I placed the order before the contest. And, he won.
>
> Raul Boerner

On the tailwheel thing: a steerable tailwheel is the best thing on a glider since sliced bread and flush toilets. Any glider, not just a self launcher..

Paul T[_4_]

November 2nd 17, 05:27 PM

Will the GP 14 Velo actually be legal to fly in FAI13.5m class in future?

Heard the GP14 and Lak's had to take out the battery's so could meet
35kg/m2 wing loading limit. So if FAI insist on FES for self launch and
35kg/m2 in 13.5 m class they are going to have a small pool of small
pilots who can compete in one legally.

Sorry having seen the GP15 at Aero not impressed - like the V3, and
SZD-56-2 they are built for the 'smaller guy'. I'll buy Schleichers or
Jonkers who design for the larger person, and still seem to have the
performance. FAI should outlaw this silly'small cockpit' practice.

[email protected]

November 2nd 17, 09:55 PM

On Thursday, November 2, 2017 at 5:30:06 PM UTC, Paul T wrote:
> Will the GP 14 Velo actually be legal to fly in FAI13.5m class in future?
>
> Heard the GP14 and Lak's had to take out the battery's so could meet
> 35kg/m2 wing loading limit. So if FAI insist on FES for self launch and
> 35kg/m2 in 13.5 m class they are going to have a small pool of small
> pilots who can compete in one legally.
>
> Sorry having seen the GP15 at Aero not impressed - like the V3, and
> SZD-56-2 they are built for the 'smaller guy'. I'll buy Schleichers or
> Jonkers who design for the larger person, and still seem to have the
> performance. FAI should outlaw this silly'small cockpit' practice.

The large ("Performance") cockpit mock-up for the V3 at Aero was too small for you?? The V3, the GP 14 and the GP 15 will all come with 2 cockpit sizes - eventually.

Paul T[_4_]

November 2nd 17, 10:39 PM

At 21:55 02 November 2017, wrote:
>On Thursday, November 2, 2017 at 5:30:06 PM UTC, Paul T wrote:
>> Will the GP 14 Velo actually be legal to fly in FAI13.5m class in
future?
>>
>> Heard the GP14 and Lak's had to take out the battery's so could
meet
>> 35kg/m2 wing loading limit. So if FAI insist on FES for self
launch and
>> 35kg/m2 in 13.5 m class they are going to have a small pool of
small
>> pilots who can compete in one legally.
>>
>> Sorry having seen the GP15 at Aero not impressed - like the V3,
and
>> SZD-56-2 they are built for the 'smaller guy'. I'll buy Schleichers
or
>> Jonkers who design for the larger person, and still seem to have
the
>> performance. FAI should outlaw this silly'small cockpit' practice.
>
>The large ("Performance") cockpit mock-up for the V3 at Aero was
too small
>for you?? The V3, the GP 14 and the GP 15 will all come with 2
cockpit
>sizes - eventually.
>

Well if the GP14 doesn't meet FAI requirements for the FAI 13.5 m
class with its small cockpit why bother?

Why bother with this craziness of two cockpit sizes to give a small
performance advantage to the jockies and stick insects amongst us?
FAI should mandate a minimum cockpit size. I doubt the V3 large
cockpit will have the performance of the V3 small cockpit - and we
will see people squeezing into the small cockpit for the performance
advantage - yet i bet the JS3 and ASG33 will beat both.

waremark

November 3rd 17, 10:45 AM

What is the ASG 33 going to be?

Kevin Neave[_2_]

November 3rd 17, 01:40 PM

Expensive

At 10:45 03 November 2017, waremark wrote:
>What is the ASG 33 going to be?
>

[email protected][_2_]

November 4th 17, 12:52 PM

On Monday, October 30, 2017 at 11:01:37 PM UTC-5, Bruce Hoult wrote:

The factory has responded to my inquiry about a some posted questions:

1) Trailer ground clearance is 340mm (13.4 inches), and
2) GP Gliders is working to get a glider to the SSA Convention.

Raul Boerner
LS6-bwl (now)
GP-15 Jeta (November 2018, or later)

Dan Marotta

November 4th 17, 02:34 PM

Hey Raul,

Be sure to bring the new toy to Moriarty!

Dan

On 11/4/2017 6:52 AM, wrote:
> On Monday, October 30, 2017 at 11:01:37 PM UTC-5, Bruce Hoult wrote:
>
> The factory has responded to my inquiry about a some posted questions:
>
> 1) Trailer ground clearance is 340mm (13.4 inches), and
> 2) GP Gliders is working to get a glider to the SSA Convention.
>
> Raul Boerner
> LS6-bwl (now)
> GP-15 Jeta (November 2018, or later)
>

--
Dan, 5J

[email protected]

November 18th 18, 11:05 PM

Raul,
Did you receive your Jeta yet?
As you mentioned, there is not much official news from the company.... At one point they announced that Kawa would compete at Ostrow in the GP-15, which was then quickly retracted. Do you know what was going on? Have there been made any changes to the Jeta as a result?
Iâ€™m quite enthusiastic about this glider, and I believe around 50 have been ordered. But it has been awfully quiet lately....

Marco

[email protected]

November 19th 18, 12:33 AM

Marco,

The news that I have is that my glider, roughly SN 12-15ish, should be completed around late spring to early summer. Dave Nelson's might be in production right now, maybe. Tom Holloran is the by now not so new, USA representative; he is doing a great job and has been doing A LOT of work getting the FAA and Port Authorities, etc. ready. He and his wife are currently in Krakow, Poland visiting the factory, and he plans to make videos of his flights in the JETA and the VELO. I can't wait.

My wife and I were in Ostrow for the 2018 WGC; we went to do flight support for our friend and fellow club member Bif Huss and his wife Ceil. We wanted to touch the JETA and speak with Mr. Kawa. Like you said, the GP-15 was retracted from the contest. The reason makes huge sense; the glider had not finished its certification flight tests. The factory did not want to expose the prototype to the riggers of a world-class competition. Mr. Kawa had to switch back to his glider. He, too, did not want to compete in a glider that was not fully ready for prime time. As good a pilot as he is, he wants everything perfect. By the way, he is very particular.

Part of the delay in testing and production was due to changes that Mr. Kawa suggested; by the way, he is the factory's technical adviser. Those changes were 1) New design winglets, 2) Wing roots streamlined to the fuselage in the negative flap position, and 3) A change in the angle of incidence of the horizontal stabilizer. So when the top glider racer in the world wants something, he usually gets it. And, he wants speed.

Other recent changes include the steerable tail wheel and a cheaper way to charge the batteries while the glider is in its trailer.

Raul Boerner

[email protected]

November 19th 18, 12:45 AM

On Sunday, November 18, 2018 at 4:05:34 PM UTC-7, wrote:
> Raul,
> Did you receive your Jeta yet?
> As you mentioned, there is not much official news from the company.... At one point they announced that Kawa would compete at Ostrow in the GP-15, which was then quickly retracted. Do you know what was going on? Have there been made any changes to the Jeta as a result?
> Iâ€™m quite enthusiastic about this glider, and I believe around 50 have been ordered. But it has been awfully quiet lately....
>
> Marco

Marco,

The news that I have is that my glider, roughly SN 12-15ish, should be completed around late spring to early summer. Dave Nelson's might be in production right now, maybe. Tom Holloran is the by now not so new, USA representative; he is doing a great job and has been doing A LOT of work getting the FAA and Port Authorities, etc. ready. He and his wife are currently in Krosno, Poland visiting the factory, and he plans to make videos of his flights in the JETA and the VELO. I can't wait.

My wife and I were in Ostrow for the 2018 WGC; we went to do flight support for our friend and fellow club member Bif Huss and his wife Ceil. We wanted to touch the JETA and speak with Mr. Kawa. Like you said, the GP-15 was retracted from the contest. The reason makes huge sense; the glider had not finished its certification flight tests. The factory did not want to expose the prototype to the riggers of a world-class competition. Mr. Kawa had to switch back to his glider. He, too, did not want to compete in a glider that was not fully ready for prime time. As good a pilot as he is, he wants everything perfect. By the way, he is very particular.

Part of the delay in testing and production was due to changes that Mr. Kawa suggested; by the way, he is the factory's technical adviser. Those changes were 1) New design winglets, 2) Wing roots streamlined to the fuselage in the negative flap position, and 3) A change in the angle of incidence of the horizontal stabilizer. So when the top glider racer in the world wants something, he usually gets it. And, he wants speed.

Other recent changes include the steerable tail wheel and a cheaper way to charge the batteries while the glider is in its trailer.

Raul Boerner

[email protected]

November 19th 18, 12:50 AM

Marco,

The news that I have is that my glider, roughly SN 12-15ish, should be completed around late spring to early summer. Dave Nelson's might be in production right now, maybe. Tom Holloran is the by now not so new, USA representative; he is doing a great job and has been doing A LOT of work getting the FAA and Port Authorities, etc. ready. He and his wife are currently in Krakow, Poland visiting the factory, and he plans to make videos of his flights in the JETA and the VELO. I can't wait.

My wife and I were in Ostrow for the 2018 WGC; we went to do flight support for our friend and fellow club member Bif Huss and his wife Ceil. We wanted to touch the JETA and speak with Mr. Kawa. Like you said, the GP-15 was retracted from the contest. The reason makes huge sense; the glider had not finished its certification flight tests. The factory did not want to expose the prototype to the rigors of a world-class competition. Mr. Kawa had to switch back to his glider. He, too, did not want to compete in a glider that was not fully ready for prime time. As good a pilot as he is, he wants everything perfect. By the way, he is very particular.

Part of the delay in testing and production was due to changes that Mr. Kawa suggested; by the way, he is the factory's technical adviser. Those changes were 1) New design winglets, 2) Wing roots streamlined to the fuselage in the negative flap position, and 3) A change in the angle of incidence of the horizontal stabilizer. So when the top glider racer in the world wants something, he usually gets it. And, he wants speed.

Other recent changes include the steerable tail wheel and a cheaper way to charge the batteries while the glider is in its trailer.

Raul Boerner

[email protected]

November 19th 18, 12:54 AM

Marco,

The news that I have is that my glider, roughly SN 12-15ish, should be completed around late spring to early summer. Dave Nelson's might be in production right now, maybe. Tom Holloran is the by now not so new, USA representative; he is doing a great job and has been doing A LOT of work getting the FAA and Port Authorities, etc. ready. He and his wife are currently in Krosno, Poland visiting the factory, and he plans to make videos of his flights in the JETA and the VELO. I can't wait.

My wife and I were in Ostrow for the 2018 WGC; we went to do flight support for our friend and fellow club member Bif Huss and his wife Ceil. We wanted to touch the JETA and speak with Mr. Kawa. Like you said, the GP-15 was retracted from the contest. The reason makes huge sense; the glider had not finished its certification flight tests. The factory did not want to expose the prototype to the rigors of a world-class competition. Mr. Kawa had to switch back to his glider. He, too, did not want to compete in a glider that was not fully ready for prime time. As good a pilot as he is, he wants everything perfect. By the way, he is very particular.

Part of the delay in testing and production was due to changes that Mr. Kawa suggested; by the way, he is the factory's technical adviser. Those changes were 1) New design winglets, 2) Wing roots streamlined to the fuselage in the negative flap position, and 3) A change in the angle of incidence of the horizontal stabilizer. So when the top glider racer in the world wants something, he usually gets it. And, he wants speed.

Other recent changes include the steerable tail wheel and a cheaper way to charge the batteries while the glider is in its trailer.

Raul Boerner

[email protected]

November 19th 18, 08:06 AM

Hi Raul,
Jerzy told me the reason for Sebastian Kawa not to compete with the GP15 prototype were problems with its wing surface (reducing the performance). Next wings will be better.
I was visiting the company last weekend and a friend did a testflight. He was very impressed - strong engine, nice to handle, very quietly while gliding. But he felt not so good while circling with high banking. There were a few other minor problems (radio antenna, error in the engine computer, difficult assembly of wings) - i am sure these points will be cleared soon.
My guess is the biggest problem for gp is finding and training a big number of good workers.
L.

Jim White[_3_]

November 19th 18, 09:55 AM

At 08:06 19 November 2018, wrote:
>Hi Raul,
>Jerzy told me the reason for Sebastian Kawa not to compete with the GP15
>pr=
>ototype were problems with its wing surface (reducing the performance).
>Nex=
>t wings will be better.
>I was visiting the company last weekend and a friend did a testflight. He
>w=
>as very impressed - strong engine, nice to handle, very quietly while
>glidi=
>ng. But he felt not so good while circling with high banking. There were
a
>=
>few other minor problems (radio antenna, error in the engine computer,
>diff=
>icult assembly of wings) - i am sure these points will be cleared soon.
>My guess is the biggest problem for gp is finding and training a big
>number=
> of good workers.
>L.
>
If the glider is set up for Seb then expect the handling in tight thermals
to be tricky!

Jonathan St. Cloud

November 19th 18, 03:56 PM

On Monday, November 19, 2018 at 2:00:10 AM UTC-8, Jim White wrote:
> At 08:06 19 November 2018, wrote:
> >Hi Raul,
> >Jerzy told me the reason for Sebastian Kawa not to compete with the GP15
> >pr=
> >ototype were problems with its wing surface (reducing the performance).
> >Nex=
> >t wings will be better.
> >I was visiting the company last weekend and a friend did a testflight. He
> >w=
> >as very impressed - strong engine, nice to handle, very quietly while
> >glidi=
> >ng. But he felt not so good while circling with high banking. There were
> a
> >=
> >few other minor problems (radio antenna, error in the engine computer,
> >diff=
> >icult assembly of wings) - i am sure these points will be cleared soon.
> >My guess is the biggest problem for gp is finding and training a big
> >number=
> > of good workers.
> >L.
> >
> If the glider is set up for Seb then expect the handling in tight thermals
> to be tricky!

Why would a glider "up set for Seb" be "tricky" and define "tricky" please. Thank you.

krasw

November 19th 18, 04:59 PM

How many gliders have GP produced so far?

Jim White[_3_]

November 20th 18, 12:02 PM

At 15:56 19 November 2018, Jonathan St. Cloud wrote:
>Why would a glider "up set for Seb" be "tricky" and define "tricky"
please.
> Thank you.

When Seb did a seminar in the UK I asked him where he set his C of G. His
answer: "as far back as the manufacturer allows, and then a bit more".

His thinking is that, in this configuration the glider, will soak up energy
from gusts better but it does make the glider much harder to fly in tight
thermals. If you are Seb, that doesn't matter.

As technical consultant to GP, I would expect that he wants the glider set
up to optimise this aspect of performance and will make compromises on
handling as a result.

Only my guess. He may be advising them to make compromises in performance
instead....

Jim

[email protected]

November 21st 18, 01:40 AM

Thanks guys! That was more info on the Jeta in 5 mins than Iâ€™ve seen in 6 months!

Btw, I was wondering if Jerzy would contemplate having his gliders build under license in another country? It seems he has a production problem.... Would that be a possible solution?

Marco.

[email protected]

June 23rd 20, 01:40 PM

Any new info about the Jeta?
I wonder if its quality and handling are like top GermÃ¡n gliders...
Cheers

[email protected]

June 23rd 20, 06:52 PM

Dear Augustin (please accept my apology if I got the spelling wrong),

In September of 2017, the wife and I visited the factory in Poland, met the people, saw and touched the glider. In 2018, we were in Ostrow for the WGC where a JETA was to compete; due to changes, it was not ready for prime time competition but was available for show and tell. Next, we saw the first USA JETA at the 2020 SSA Convention in Little Rock, Arkansas. The quality of the finish was wonderful. But in the factory's rush to meet USA shipping deadlines to make the Convention, some mistakes were made; these are being fixed with parts finally on the way, thanks to the re-opening of the factory and its suppliers. The Coronavirus has been a BIG NEGATIVE everywhere.

There have been numerous changes and improvements; all of which I welcome. One of the changes is a lower RPM motor, with a larger propeller and rudder.. Yes, those delays, coupled with Coronavirus shutdowns of glider factories, navigation equipment manufacturers, and all other vendors, are a frustration. My controlled excitement won't help the factory resume interviewing construction employees (who left the country looking for work elsewhere). But, I'm a patient man.

Also, EASA changed certification requirements for aircraft over 600 KG. The Germans and French chose to apply these to aircraft weighing less than 600 KG, too. This added an additional six-month delay to all new gliders.

Our USA Representative wrote an article about his flight in the JETA; it is in the November, 2019 edition of SOARING magazine. He is a highly respected and successful competitor. Me? I'm just a Regional Contest pilot with only one National under my overly cautious belt.

We JETA owners, along with interested observers, are all waiting for word from our first USA JETA owner. As a comparison, a friend of mine waited over five years for his new Ventus, so I understand stuff happens; unfortunately yet predictably it showed up with a list of problems, including an engine failure on its first self-launch. With problems now fixed, the owner is joyfully self-launching and flying long tasks. So when my JETA finally gets here, it will provide me with what I want and need in this stage of my flying life. As far as these delays and improvements are concerned, I'll patiently wait; because I'm a positive thinker with skin in the game. So, I'll just keep teaching and waiting for a contest. Selling my LS6-BWL, with its disk brake conversion and winglets, will have to wait for prices to return to normal.

Raul

June 24th 20, 04:09 AM

On Tuesday, June 23, 2020 at 10:52:43 AM UTC-7, wrote:
> Dear Augustin (please accept my apology if I got the spelling wrong),
>
> In September of 2017, the wife and I visited the factory in Poland, met the people, saw and touched the glider. In 2018, we were in Ostrow for the WGC where a JETA was to compete; due to changes, it was not ready for prime time competition but was available for show and tell. Next, we saw the first USA JETA at the 2020 SSA Convention in Little Rock, Arkansas. The quality of the finish was wonderful. But in the factory's rush to meet USA shipping deadlines to make the Convention, some mistakes were made; these are being fixed with parts finally on the way, thanks to the re-opening of the factory and its suppliers. The Coronavirus has been a BIG NEGATIVE everywhere.
>
> There have been numerous changes and improvements; all of which I welcome.. One of the changes is a lower RPM motor, with a larger propeller and rudder. Yes, those delays, coupled with Coronavirus shutdowns of glider factories, navigation equipment manufacturers, and all other vendors, are a frustration. My controlled excitement won't help the factory resume interviewing construction employees (who left the country looking for work elsewhere). But, I'm a patient man.
>
> Also, EASA changed certification requirements for aircraft over 600 KG. The Germans and French chose to apply these to aircraft weighing less than 600 KG, too. This added an additional six-month delay to all new gliders.
>
> Our USA Representative wrote an article about his flight in the JETA; it is in the November, 2019 edition of SOARING magazine. He is a highly respected and successful competitor. Me? I'm just a Regional Contest pilot with only one National under my overly cautious belt.
>
> We JETA owners, along with interested observers, are all waiting for word from our first USA JETA owner. As a comparison, a friend of mine waited over five years for his new Ventus, so I understand stuff happens; unfortunately yet predictably it showed up with a list of problems, including an engine failure on its first self-launch. With problems now fixed, the owner is joyfully self-launching and flying long tasks. So when my JETA finally gets here, it will provide me with what I want and need in this stage of my flying life. As far as these delays and improvements are concerned, I'll patiently wait; because I'm a positive thinker with skin in the game. So, I'll just keep teaching and waiting for a contest. Selling my LS6-BWL, with its disk brake conversion and winglets, will have to wait for prices to return to normal.
>
> Raul

This sounds like putting lipstick on a pig: have any GP-15's been delivered to the US that have received airworthiness certificates? If so, how many?

Tom

[email protected]

June 24th 20, 11:45 AM

>Also, EASA changed certification requirements for aircraft over 600 KG. The Germans and French chose to apply these to aircraft weighing less than 600 KG, too. This added an additional six-month delay to all new gliders.

What changed?

Nick Kennedy[_3_]

June 24th 20, 02:44 PM

On paper the GP-15 looks very very nice, with all the latest bells and whistles. It checks a lot of boxes off the list.
They seem to be having a major problem overcoming a major important hurtle, delivering completed debugged Ready to Fly ships to customers.
As we know gliders are pretty much hand made, most everyone is a little different than the last or next one coming off the line.
I wish GP all the best, I really hope they can ramp up production and start delivering High quality ships to anxious buyers, that perform as advertised.
Nick
T

Jonathan St. Cloud

June 24th 20, 03:13 PM

On Tuesday, June 23, 2020 at 8:09:59 PM UTC-7, 2G wrote:
> On Tuesday, June 23, 2020 at 10:52:43 AM UTC-7, wrote:
> > Dear Augustin (please accept my apology if I got the spelling wrong),
> >
> > In September of 2017, the wife and I visited the factory in Poland, met the people, saw and touched the glider. In 2018, we were in Ostrow for the WGC where a JETA was to compete; due to changes, it was not ready for prime time competition but was available for show and tell. Next, we saw the first USA JETA at the 2020 SSA Convention in Little Rock, Arkansas. The quality of the finish was wonderful. But in the factory's rush to meet USA shipping deadlines to make the Convention, some mistakes were made; these are being fixed with parts finally on the way, thanks to the re-opening of the factory and its suppliers. The Coronavirus has been a BIG NEGATIVE everywhere..
> >
> > There have been numerous changes and improvements; all of which I welcome. One of the changes is a lower RPM motor, with a larger propeller and rudder. Yes, those delays, coupled with Coronavirus shutdowns of glider factories, navigation equipment manufacturers, and all other vendors, are a frustration. My controlled excitement won't help the factory resume interviewing construction employees (who left the country looking for work elsewhere). But, I'm a patient man.
> >
> > Also, EASA changed certification requirements for aircraft over 600 KG. The Germans and French chose to apply these to aircraft weighing less than 600 KG, too. This added an additional six-month delay to all new gliders.
> >
> > Our USA Representative wrote an article about his flight in the JETA; it is in the November, 2019 edition of SOARING magazine. He is a highly respected and successful competitor. Me? I'm just a Regional Contest pilot with only one National under my overly cautious belt.
> >
> > We JETA owners, along with interested observers, are all waiting for word from our first USA JETA owner. As a comparison, a friend of mine waited over five years for his new Ventus, so I understand stuff happens; unfortunately yet predictably it showed up with a list of problems, including an engine failure on its first self-launch. With problems now fixed, the owner is joyfully self-launching and flying long tasks. So when my JETA finally gets here, it will provide me with what I want and need in this stage of my flying life. As far as these delays and improvements are concerned, I'll patiently wait; because I'm a positive thinker with skin in the game. So, I'll just keep teaching and waiting for a contest. Selling my LS6-BWL, with its disk brake conversion and winglets, will have to wait for prices to return to normal.
> >
> > Raul
>
> This sounds like putting lipstick on a pig: have any GP-15's been delivered to the US that have received airworthiness certificates? If so, how many?
>
> Tom

Tom before you die I hope you learn that words do hurt and you are so quick to issue damning judgement. Sounds like a new project developing to me. Is you analysis of a V2C vs a V2CX the same, just lip stick. How about the Arcus and new Arcus. GP as I understand it is a new company putting out a new product. That is not lipstick that is business, which takes risk and money and much effort. I applaud what they are doing. However, for now I am happy with the gliders that have an operational history.

Andrzej Kobus

June 25th 20, 02:25 AM

On Wednesday, June 24, 2020 at 10:13:13 AM UTC-4, Jonathan St. Cloud wrote:
> On Tuesday, June 23, 2020 at 8:09:59 PM UTC-7, 2G wrote:
> > On Tuesday, June 23, 2020 at 10:52:43 AM UTC-7, wrote:
> > > Dear Augustin (please accept my apology if I got the spelling wrong),
> > >
> > > In September of 2017, the wife and I visited the factory in Poland, met the people, saw and touched the glider. In 2018, we were in Ostrow for the WGC where a JETA was to compete; due to changes, it was not ready for prime time competition but was available for show and tell. Next, we saw the first USA JETA at the 2020 SSA Convention in Little Rock, Arkansas. The quality of the finish was wonderful. But in the factory's rush to meet USA shipping deadlines to make the Convention, some mistakes were made; these are being fixed with parts finally on the way, thanks to the re-opening of the factory and its suppliers. The Coronavirus has been a BIG NEGATIVE everywhere.
> > >
> > > There have been numerous changes and improvements; all of which I welcome. One of the changes is a lower RPM motor, with a larger propeller and rudder. Yes, those delays, coupled with Coronavirus shutdowns of glider factories, navigation equipment manufacturers, and all other vendors, are a frustration. My controlled excitement won't help the factory resume interviewing construction employees (who left the country looking for work elsewhere). But, I'm a patient man.
> > >
> > > Also, EASA changed certification requirements for aircraft over 600 KG. The Germans and French chose to apply these to aircraft weighing less than 600 KG, too. This added an additional six-month delay to all new gliders..
> > >
> > > Our USA Representative wrote an article about his flight in the JETA; it is in the November, 2019 edition of SOARING magazine. He is a highly respected and successful competitor. Me? I'm just a Regional Contest pilot with only one National under my overly cautious belt.
> > >
> > > We JETA owners, along with interested observers, are all waiting for word from our first USA JETA owner. As a comparison, a friend of mine waited over five years for his new Ventus, so I understand stuff happens; unfortunately yet predictably it showed up with a list of problems, including an engine failure on its first self-launch. With problems now fixed, the owner is joyfully self-launching and flying long tasks. So when my JETA finally gets here, it will provide me with what I want and need in this stage of my flying life. As far as these delays and improvements are concerned, I'll patiently wait; because I'm a positive thinker with skin in the game. So, I'll just keep teaching and waiting for a contest. Selling my LS6-BWL, with its disk brake conversion and winglets, will have to wait for prices to return to normal.
> > >
> > > Raul
> >
> > This sounds like putting lipstick on a pig: have any GP-15's been delivered to the US that have received airworthiness certificates? If so, how many?
> >
> > Tom
>
> Tom before you die I hope you learn that words do hurt and you are so quick to issue damning judgement. Sounds like a new project developing to me. Is you analysis of a V2C vs a V2CX the same, just lip stick. How about the Arcus and new Arcus. GP as I understand it is a new company putting out a new product. That is not lipstick that is business, which takes risk and money and much effort. I applaud what they are doing. However, for now I am happy with the gliders that have an operational history.

Jonathan, every date the company said they blew. They are simply not trust worthy. I would not give them a dime. They keep tinkering and taking money from people, do you think they have money to actually build the gliders, I doubt it. So it seems like a ponzi scheme to me. I talked to them years ago and was very impressed but that changed as the years went by.

Nick Kennedy[_3_]

June 25th 20, 03:51 PM

Andrzei, or anyone who actually knows;
How many years has it been since GP cashed the first prepurchase check they received?
Just curious
Nick
T

[email protected]

June 25th 20, 04:36 PM

Hello Nick,

For me, it was two and a half years ago; I expected several years waiting. So far, no surprises there.

PESZKE Company has been around for awhile. Quoting their Background link: In 2007 father and son decided to become business partners and set up a new company, with Grzegorz handling the design and engineering and Jerzy managing the business and sales. The first significant project was a 4-year joint venture with several Czech aviation firms, where PESZKE designed, developed and implemented into production 2 types of light sport aircraft - the GP5 and GP6. In parallel PESZKE has set up a production division producing carbon fibre aviation propellers, dedicated to ultralights and powered para-gliders.

Having visited the father and son, toured the factory and asked airport locals about the family, I felt comfortable placing my order.

Raul

June 26th 20, 02:34 PM

On Wednesday, June 24, 2020 at 7:13:13 AM UTC-7, Jonathan St. Cloud wrote:
> On Tuesday, June 23, 2020 at 8:09:59 PM UTC-7, 2G wrote:
> > On Tuesday, June 23, 2020 at 10:52:43 AM UTC-7, wrote:
> > > Dear Augustin (please accept my apology if I got the spelling wrong),
> > >
> > > In September of 2017, the wife and I visited the factory in Poland, met the people, saw and touched the glider. In 2018, we were in Ostrow for the WGC where a JETA was to compete; due to changes, it was not ready for prime time competition but was available for show and tell. Next, we saw the first USA JETA at the 2020 SSA Convention in Little Rock, Arkansas. The quality of the finish was wonderful. But in the factory's rush to meet USA shipping deadlines to make the Convention, some mistakes were made; these are being fixed with parts finally on the way, thanks to the re-opening of the factory and its suppliers. The Coronavirus has been a BIG NEGATIVE everywhere.
> > >
> > > There have been numerous changes and improvements; all of which I welcome. One of the changes is a lower RPM motor, with a larger propeller and rudder. Yes, those delays, coupled with Coronavirus shutdowns of glider factories, navigation equipment manufacturers, and all other vendors, are a frustration. My controlled excitement won't help the factory resume interviewing construction employees (who left the country looking for work elsewhere). But, I'm a patient man.
> > >
> > > Also, EASA changed certification requirements for aircraft over 600 KG. The Germans and French chose to apply these to aircraft weighing less than 600 KG, too. This added an additional six-month delay to all new gliders..
> > >
> > > Our USA Representative wrote an article about his flight in the JETA; it is in the November, 2019 edition of SOARING magazine. He is a highly respected and successful competitor. Me? I'm just a Regional Contest pilot with only one National under my overly cautious belt.
> > >
> > > We JETA owners, along with interested observers, are all waiting for word from our first USA JETA owner. As a comparison, a friend of mine waited over five years for his new Ventus, so I understand stuff happens; unfortunately yet predictably it showed up with a list of problems, including an engine failure on its first self-launch. With problems now fixed, the owner is joyfully self-launching and flying long tasks. So when my JETA finally gets here, it will provide me with what I want and need in this stage of my flying life. As far as these delays and improvements are concerned, I'll patiently wait; because I'm a positive thinker with skin in the game. So, I'll just keep teaching and waiting for a contest. Selling my LS6-BWL, with its disk brake conversion and winglets, will have to wait for prices to return to normal.
> > >
> > > Raul
> >
> > This sounds like putting lipstick on a pig: have any GP-15's been delivered to the US that have received airworthiness certificates? If so, how many?
> >
> > Tom
>
> Tom before you die I hope you learn that words do hurt and you are so quick to issue damning judgement. Sounds like a new project developing to me. Is you analysis of a V2C vs a V2CX the same, just lip stick. How about the Arcus and new Arcus. GP as I understand it is a new company putting out a new product. That is not lipstick that is business, which takes risk and money and much effort. I applaud what they are doing. However, for now I am happy with the gliders that have an operational history.

People are putting down real money with the expectation of getting a real glider. I have heard that there are over 30 orders for the GP-15 in the US alone, one of which is a friend of mine. He was given a December delivery date. I asked a simple question: how many GP-15s have received airworthiness certificates - you ignored that entirely. Do you know the answer? If so, I eagerly await your response. Otherwise, you are just assisting in applying the lipstick.

Tom

Jonathan St. Cloud

June 27th 20, 11:55 PM

Never mind.

June 28th 20, 04:37 AM

On Saturday, June 27, 2020 at 3:55:40 PM UTC-7, Jonathan St. Cloud wrote:
> Never mind.

Excellent advice for yourself.

Mike N.

June 28th 20, 08:03 PM

On Saturday, June 27, 2020 at 9:37:42 PM UTC-6, 2G wrote:
> On Saturday, June 27, 2020 at 3:55:40 PM UTC-7, Jonathan St. Cloud wrote:
> > Never mind.
>
> Excellent advice for yourself.

Seriously you and Daryl K. MUST be related....

Jonathan St. Cloud

June 29th 20, 07:11 AM

Fair enough, although, I am accepting your bit of unsolicited life advice with a tad more humility than you afforded me. Thus my original point. Tom, it is not too late to calm that rather prickly manner of treating all you encounter.
Good day to you

[email protected]

June 29th 20, 11:17 AM

As far as I know, there is no European type certificate for any of the GP Gliders. I was unable to find neither GP Gliders nor the parent company Peszke as an aircraft manufacturer when looking in the EASA certification database. No TCDS - Type Certificate Data Sheet - available. Some or all of these gliders may fall under the (recently modified) ultralight category, where no certification is mandatory.

Eric Greenwell[_4_]

June 29th 20, 03:08 PM

wrote on 6/29/2020 3:17 AM:
> As far as I know, there is no European type certificate for any of the GP Gliders. I was unable to find neither GP Gliders nor the parent company Peszke as an aircraft manufacturer when looking in the EASA certification database. No TCDS - Type Certificate Data Sheet - available. Some or all of these gliders may fall under the (recently modified) ultralight category, where no certification is mandatory.
>
Type certificates aren't required to import a glider in the US. I had my ASH 26E
in March 1995, licensed in the Experimental category; it was about two years later
that they received German certification. Ditto for the ASW 27, also a new glider
at the time. Other countries have different rules, but gliders are produced, sold,
and delivered before receiving certification.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications/download-the-guide-1

kinsell

June 29th 20, 03:58 PM

On 6/29/20 8:08 AM, Eric Greenwell wrote:
> wrote on 6/29/2020 3:17 AM:
>> As far as I know, there is no European type certificate for any of the
>> GP Gliders. I was unable to find neither GP Gliders nor the parent
>> company Peszke as an aircraft manufacturer when looking in the EASA
>> certification database. No TCDS - Type Certificate Data Sheet -
>> available. Some or all of these gliders may fall under the (recently
>> modified) ultralight category, where no certification is mandatory.
>>
> Type certificates aren't required to import a glider in the US. I had my
> ASH 26E in March 1995, licensed in the Experimental category; it was
> about two years later that they received German certification. Ditto for
> the ASW 27, also a new glider at the time. Other countries have
> different rules, but gliders are produced, sold, and delivered before
> receiving certification.
>

The November Soaring article claimed two GP-14's had been delivered to
Italy. Any word on how those are doing?

krasw

June 29th 20, 06:06 PM

On Monday, 29 June 2020 13:17:56 UTC+3, wrote:
> As far as I know, there is no European type certificate for any of the GP Gliders. I was unable to find neither GP Gliders nor the parent company Peszke as an aircraft manufacturer when looking in the EASA certification database. No TCDS - Type Certificate Data Sheet - available. Some or all of these gliders may fall under the (recently modified) ultralight category, where no certification is mandatory.

I think they have no intention of certifying it, it is national ultra light only.

[email protected]

June 29th 20, 07:38 PM

That's also my understanding. It probably is no problem in the USA if the FAA accepts them in the experimental category.

However, in Europe, that means you can't cross a border with them, unless you get an exemption from the other country.

About certification, the EASA exemption rule states:

8. A Member State may decide to exempt from this Regulation the design, production, maintenance and operation activities in respect of one or more of the following categories of aircraft:

(a) aeroplanes, other than unmanned aeroplanes, which have no more than two seats, measurable stall speed or minimum steady flight speed in landing configuration not exceeding 45 knots calibrated air speed and a maximum take-off mass (MTOM), as recorded by the Member State, of no more than 600 kg for aeroplanes not intended to be operated on water or 650 kg for aeroplanes intended to be operated on water;

(b) helicopters, other than unmanned helicopters, which have no more than two seats and a MTOM, as recorded by the Member State, of no more than 600 kg for helicopters not intended to be operated on water or 650 kg for helicopters intended to be operated on water;

(c) sailplanes, other than unmanned sailplanes, and powered sailplanes, other than unmanned powered sailplanes, which have no more than two seats and a MTOM, as recorded by the Member State, of no more than 600 kg.

The funny thing here is that there is a minimum stall speed for aeroplanes, but not for gliders...

In reality, not all European states are considering all the abovementioned aircraft as exempted from certification. France, for example, is more restrictive than Germany in this respect, with more stringent limits for MTM, because the ultralight movement in France fears to lose the very supple system they have (no national certification, no medical, possibility to land and take-off anywhere with simple authorization from the landowner, etc.)

Germany on the contrary has much more restrictive national rules on the use of ultralights, with a (limited) national certification and no taking off outside of an airfield, but I believe they apply these certification exemptions to their full extent, at least for ultralight aeroplanes and helicopters. I'm not so sure about the pure gliders. So you have no guarantee whatsoever to be able to use such an uncertified glider outside your own country in Europe.

Now if you live in a big country, that is perhaps no problem for you. But I live in Belgium. The downwind leg for my airfield is over French territory....

krasw

June 29th 20, 08:08 PM

On Monday, 29 June 2020 21:38:42 UTC+3, wrote:
> That's also my understanding. It probably is no problem in the USA if the FAA accepts them in the experimental category.
>
> However, in Europe, that means you can't cross a border with them, unless you get an exemption from the other country.

Our ultralights fly all over EU. You have as many rules as you have nations.

[email protected]

June 30th 20, 01:16 AM

> Our ultralights fly all over EU. You have as many rules as you have nations.

When EASA came into being, you ended up with not the AVERAGE of the member nation's regulations, but the SUM of the member nation's regulations.

June 30th 20, 03:31 AM

On Sunday, June 28, 2020 at 12:03:53 PM UTC-7, Mike N. wrote:
> On Saturday, June 27, 2020 at 9:37:42 PM UTC-6, 2G wrote:
> > On Saturday, June 27, 2020 at 3:55:40 PM UTC-7, Jonathan St. Cloud wrote:
> > > Never mind.
> >
> > Excellent advice for yourself.
>
> Seriously you and Daryl K. MUST be related....

Seriously, you're full of ****...

June 30th 20, 03:33 AM

On Sunday, June 28, 2020 at 11:11:44 PM UTC-7, Jonathan St. Cloud wrote:
> Fair enough, although, I am accepting your bit of unsolicited life advice with a tad more humility than you afforded me. Thus my original point. Tom, it is not too late to calm that rather prickly manner of treating all you encounter.
> Good day to you

JSC, I call em as I see em.

Eric Greenwell[_4_]

June 30th 20, 04:56 AM

kinsell wrote on 6/29/2020 7:58 AM:
> On 6/29/20 8:08 AM, Eric Greenwell wrote:
>> wrote on 6/29/2020 3:17 AM:
>>> As far as I know, there is no European type certificate for any of the GP
>>> Gliders. I was unable to find neither GP Gliders nor the parent company Peszke
>>> as an aircraft manufacturer when looking in the EASA certification database. No
>>> TCDS - Type Certificate Data Sheet - available. Some or all of these gliders
>>> may fall under the (recently modified) ultralight category, where no
>>> certification is mandatory.
>>>
>> Type certificates aren't required to import a glider in the US. I had my ASH 26E
>> in March 1995, licensed in the Experimental category; it was about two years
>> later that they received German certification. Ditto for the ASW 27, also a new
>> glider at the time. Other countries have different rules, but gliders are
>> produced, sold, and delivered before receiving certification.
>>
>
> The November Soaring article claimed two GP-14's had been delivered to Italy.* Any
> word on how those are doing?
I haven't heard anything, but then US focus is entirely on the GP15.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications/download-the-guide-1

krasw

June 30th 20, 07:07 AM

On Tuesday, 30 June 2020 03:16:57 UTC+3, wrote:
> > Our ultralights fly all over EU. You have as many rules as you have nations.
>
> When EASA came into being, you ended up with not the AVERAGE of the member nation's regulations, but the SUM of the member nation's regulations.

TMostly true, but again, EASA does not regulate UL category aircraft (close to US LSA) in any way. They are under national regulation of member states.

jld

August 16th 20, 02:06 PM

I did not look at this group for a while (busy flying :-) ), and I am surprised at the amount of discussions and in some cases approximate information concerning the GP15.

From all info provided by GP multiple times, no EASA certification is planned for the GP15. It is going to be registered as UL in key EU countries (and experimental in US).
As far as crossing EU borders with UL, some countries indeed require a permit to fly for foreign UL but that is usually very easy to obtain. As a reminder, which is also applicable to certified gliders, the rules also say that it is necessary to file a flight plan when crossing borders!

Concerning GP15 approval as UL in EU, some countries like Germany have requirements concerning ground/flight tests which are rather time and budget consuming (you can't take the business risk to duplicate these tests). It is therefore logical that GP is eventually converging toward a single stable configuration that can meet approval in all targeted countries.
The haters are going to say that GP should have thought about it sooner but the reality is that the rules in EU, concerning below 600 kg aircraft (UL), have changed while GP was in the middle of the making of their gliders!
GP will now be able to rationalize/industrialize their production tools which shall allow increased production rates, reduce the risk of orphan configurations and help them become profitable (if the later does not happen that would be the end of the story anyway).

For people looking for an electric motor glider with motorized performance close to the gas burning versions, GP15 is the only game in town.
GP is on a virtuous circle: reducing weight and surface while increasing aspect ratio!
This makes possible the design of a high performance electric power plant for a total weight (motor/controller/batteries) similar to gas powered powerplant. This is what GP has done.
One side benefit of the lower power motor, coupled with rather large battery capacity, is that it reduces the max current seen by each battery cell. This allows reduced temperature excursion, simplified temperature management and reduced risks of temperature runaway.

We all would enjoy better communication from GP but, let's be honest, the well established companies are not better while taking much less risks than GP.

I feel GP is on the right path and the family is doing its best to manage the situation, COVID did not help. There has been too many delays, especially for the people who have placed orders 2 or 3 years ago, but they have a unique great design which will become a game changer, we hope pretty soon!

August 16th 20, 07:29 PM

On Sunday, August 16, 2020 at 6:06:14 AM UTC-7, jld wrote:
> I did not look at this group for a while (busy flying :-) ), and I am surprised at the amount of discussions and in some cases approximate information concerning the GP15.
>
> From all info provided by GP multiple times, no EASA certification is planned for the GP15. It is going to be registered as UL in key EU countries (and experimental in US).
> As far as crossing EU borders with UL, some countries indeed require a permit to fly for foreign UL but that is usually very easy to obtain. As a reminder, which is also applicable to certified gliders, the rules also say that it is necessary to file a flight plan when crossing borders!
>
> Concerning GP15 approval as UL in EU, some countries like Germany have requirements concerning ground/flight tests which are rather time and budget consuming (you can't take the business risk to duplicate these tests). It is therefore logical that GP is eventually converging toward a single stable configuration that can meet approval in all targeted countries.
> The haters are going to say that GP should have thought about it sooner but the reality is that the rules in EU, concerning below 600 kg aircraft (UL), have changed while GP was in the middle of the making of their gliders!
> GP will now be able to rationalize/industrialize their production tools which shall allow increased production rates, reduce the risk of orphan configurations and help them become profitable (if the later does not happen that would be the end of the story anyway).
>
> For people looking for an electric motor glider with motorized performance close to the gas burning versions, GP15 is the only game in town.
> GP is on a virtuous circle: reducing weight and surface while increasing aspect ratio!
> This makes possible the design of a high performance electric power plant for a total weight (motor/controller/batteries) similar to gas powered powerplant. This is what GP has done.
> One side benefit of the lower power motor, coupled with rather large battery capacity, is that it reduces the max current seen by each battery cell. This allows reduced temperature excursion, simplified temperature management and reduced risks of temperature runaway.
>
> We all would enjoy better communication from GP but, let's be honest, the well established companies are not better while taking much less risks than GP.
>
> I feel GP is on the right path and the family is doing its best to manage the situation, COVID did not help. There has been too many delays, especially for the people who have placed orders 2 or 3 years ago, but they have a unique great design which will become a game changer, we hope pretty soon!

600 kg is considered to be an ultralight in the EU? WOW! In the US a powered ultralight is limited to 115 kg (254 lb). This is the weight of an LSA (1320 lbs):

To be considered an ultralight vehicle, a hang glider must weigh less than 155 pounds; while a powered vehicle must weigh less than 254 pounds; is limited to 5 U.S. gallons of fuel; must have a maximum speed of not more than 55 knots; and must have a poweroff stall speed of no more than 24 knots.
https://www.usua.org/Rules/faa103.htm#:~:text=To%20be%20considered%20an%20ult ralight,no%20more%20than%2024%20knots.

In fact, there are no universal EU regulations governing ultralight aircraft - each country has its own regulations (or none at all):
https://ul-center.com/2016/03/09/ultralight-flying-in-east-europe-rules-regulations-and-other-important-information/

More guidance on this regulatory issue is in:
https://www.easa.europa.eu/sites/default/files/dfu/03%20-%20Final%20Report%2026%20Nov%2010.pdf

But it contains this confusing statement:

Gliders without an engine enabling self-launch if < 450kgs (two-seat) or 300kgs
(single-seat) are within the scope of Community regulations. Gliders with engines
enabling self-launch and which are > 450 / 300kgs MTOM microlight limits are with
the scope of Community regulations.

GP Gliders lists the MTOW of the GP-15 on their website at 470 kg (who knows what the final number will be), putting it well into the EU regulatory claws by 170 kg. So I don't see how they can fly underneath the EU regulatory radar as an ultralight without losing 170 kg of weight, which seems highly unlikely.

Most gliders imported into the US in the experimental category have a type certificate in the EU. Will the FAA be more hesitant in issuing experimental airworthiness certificates to gliders that have not undergone this certification testing? We will just have to wait and see how this unfolds. To date, I do not know of any GP-15 that has been certified anywhere, although the prototype displayed at the convention had a Slovakian registration number which I have previously shown was assigned to another aircraft. Some have said that that aircraft "could" have been deregistered and, then, reassigned to the GP-15, but have produced exactly zero proof that that had occurred..

You imply that I am a "GP hater." I take exception with this characterization - I don't "hate" GP any more or less than any other startup aircraft manufacturer. Maybe they will ultimately deliver the goods they have promised, and maybe they won't. But I do believe that anyone putting down $105,000 on an unfinished glider deserves to be told the whole truth. And "feeling" that they are on the right path does not count as truth.

Tom

August 16th 20, 07:36 PM

On Sunday, August 16, 2020 at 11:29:16 AM UTC-7, 2G wrote:
> On Sunday, August 16, 2020 at 6:06:14 AM UTC-7, jld wrote:
> > I did not look at this group for a while (busy flying :-) ), and I am surprised at the amount of discussions and in some cases approximate information concerning the GP15.
> >
> > From all info provided by GP multiple times, no EASA certification is planned for the GP15. It is going to be registered as UL in key EU countries (and experimental in US).
> > As far as crossing EU borders with UL, some countries indeed require a permit to fly for foreign UL but that is usually very easy to obtain. As a reminder, which is also applicable to certified gliders, the rules also say that it is necessary to file a flight plan when crossing borders!
> >
> > Concerning GP15 approval as UL in EU, some countries like Germany have requirements concerning ground/flight tests which are rather time and budget consuming (you can't take the business risk to duplicate these tests). It is therefore logical that GP is eventually converging toward a single stable configuration that can meet approval in all targeted countries.
> > The haters are going to say that GP should have thought about it sooner but the reality is that the rules in EU, concerning below 600 kg aircraft (UL), have changed while GP was in the middle of the making of their gliders!
> > GP will now be able to rationalize/industrialize their production tools which shall allow increased production rates, reduce the risk of orphan configurations and help them become profitable (if the later does not happen that would be the end of the story anyway).
> >
> > For people looking for an electric motor glider with motorized performance close to the gas burning versions, GP15 is the only game in town.
> > GP is on a virtuous circle: reducing weight and surface while increasing aspect ratio!
> > This makes possible the design of a high performance electric power plant for a total weight (motor/controller/batteries) similar to gas powered powerplant. This is what GP has done.
> > One side benefit of the lower power motor, coupled with rather large battery capacity, is that it reduces the max current seen by each battery cell. This allows reduced temperature excursion, simplified temperature management and reduced risks of temperature runaway.
> >
> > We all would enjoy better communication from GP but, let's be honest, the well established companies are not better while taking much less risks than GP.
> >
> > I feel GP is on the right path and the family is doing its best to manage the situation, COVID did not help. There has been too many delays, especially for the people who have placed orders 2 or 3 years ago, but they have a unique great design which will become a game changer, we hope pretty soon!
> 600 kg is considered to be an ultralight in the EU? WOW! In the US a powered ultralight is limited to 115 kg (254 lb). This is the weight of an LSA (1320 lbs):
>
> To be considered an ultralight vehicle, a hang glider must weigh less than 155 pounds; while a powered vehicle must weigh less than 254 pounds; is limited to 5 U.S. gallons of fuel; must have a maximum speed of not more than 55 knots; and must have a poweroff stall speed of no more than 24 knots.
> https://www.usua.org/Rules/faa103.htm#:~:text=To%20be%20considered%20an%20ult ralight,no%20more%20than%2024%20knots.
>
> In fact, there are no universal EU regulations governing ultralight aircraft - each country has its own regulations (or none at all):
> https://ul-center.com/2016/03/09/ultralight-flying-in-east-europe-rules-regulations-and-other-important-information/
>
> More guidance on this regulatory issue is in:
> https://www.easa.europa.eu/sites/default/files/dfu/03%20-%20Final%20Report%2026%20Nov%2010.pdf
>
> But it contains this confusing statement:
>
> Gliders without an engine enabling self-launch if < 450kgs (two-seat) or 300kgs
> (single-seat) are within the scope of Community regulations. Gliders with engines
> enabling self-launch and which are > 450 / 300kgs MTOM microlight limits are with
> the scope of Community regulations.
>
> GP Gliders lists the MTOW of the GP-15 on their website at 470 kg (who knows what the final number will be), putting it well into the EU regulatory claws by 170 kg. So I don't see how they can fly underneath the EU regulatory radar as an ultralight without losing 170 kg of weight, which seems highly unlikely.
>
> Most gliders imported into the US in the experimental category have a type certificate in the EU. Will the FAA be more hesitant in issuing experimental airworthiness certificates to gliders that have not undergone this certification testing? We will just have to wait and see how this unfolds. To date, I do not know of any GP-15 that has been certified anywhere, although the prototype displayed at the convention had a Slovakian registration number which I have previously shown was assigned to another aircraft. Some have said that that aircraft "could" have been deregistered and, then, reassigned to the GP-15, but have produced exactly zero proof that that had occurred.
>
> You imply that I am a "GP hater." I take exception with this characterization - I don't "hate" GP any more or less than any other startup aircraft manufacturer. Maybe they will ultimately deliver the goods they have promised, and maybe they won't. But I do believe that anyone putting down $105,000 on an unfinished glider deserves to be told the whole truth. And "feeling" that they are on the right path does not count as truth.
>
> Tom

Right after posting this I found that the EU has, indeed, raised the ultralight weight limit to 600 kg:

https://flightdesign.com/easa-new-basic-regulation-600-kg-ul-aircraft/

Tom

waremark

August 16th 20, 10:09 PM

That article about lifting the max gross for an ultralight to 600 kg was reporting a decision of the EU parliament more than 2 years ago.

August 16th 20, 10:35 PM

On Sunday, August 16, 2020 at 11:36:09 AM UTC-7, 2G wrote:
> On Sunday, August 16, 2020 at 11:29:16 AM UTC-7, 2G wrote:
> > On Sunday, August 16, 2020 at 6:06:14 AM UTC-7, jld wrote:
> > > I did not look at this group for a while (busy flying :-) ), and I am surprised at the amount of discussions and in some cases approximate information concerning the GP15.
> > >
> > > From all info provided by GP multiple times, no EASA certification is planned for the GP15. It is going to be registered as UL in key EU countries (and experimental in US).
> > > As far as crossing EU borders with UL, some countries indeed require a permit to fly for foreign UL but that is usually very easy to obtain. As a reminder, which is also applicable to certified gliders, the rules also say that it is necessary to file a flight plan when crossing borders!
> > >
> > > Concerning GP15 approval as UL in EU, some countries like Germany have requirements concerning ground/flight tests which are rather time and budget consuming (you can't take the business risk to duplicate these tests). It is therefore logical that GP is eventually converging toward a single stable configuration that can meet approval in all targeted countries.
> > > The haters are going to say that GP should have thought about it sooner but the reality is that the rules in EU, concerning below 600 kg aircraft (UL), have changed while GP was in the middle of the making of their gliders!
> > > GP will now be able to rationalize/industrialize their production tools which shall allow increased production rates, reduce the risk of orphan configurations and help them become profitable (if the later does not happen that would be the end of the story anyway).
> > >
> > > For people looking for an electric motor glider with motorized performance close to the gas burning versions, GP15 is the only game in town.
> > > GP is on a virtuous circle: reducing weight and surface while increasing aspect ratio!
> > > This makes possible the design of a high performance electric power plant for a total weight (motor/controller/batteries) similar to gas powered powerplant. This is what GP has done.
> > > One side benefit of the lower power motor, coupled with rather large battery capacity, is that it reduces the max current seen by each battery cell. This allows reduced temperature excursion, simplified temperature management and reduced risks of temperature runaway.
> > >
> > > We all would enjoy better communication from GP but, let's be honest, the well established companies are not better while taking much less risks than GP.
> > >
> > > I feel GP is on the right path and the family is doing its best to manage the situation, COVID did not help. There has been too many delays, especially for the people who have placed orders 2 or 3 years ago, but they have a unique great design which will become a game changer, we hope pretty soon!
> > 600 kg is considered to be an ultralight in the EU? WOW! In the US a powered ultralight is limited to 115 kg (254 lb). This is the weight of an LSA (1320 lbs):
> >
> > To be considered an ultralight vehicle, a hang glider must weigh less than 155 pounds; while a powered vehicle must weigh less than 254 pounds; is limited to 5 U.S. gallons of fuel; must have a maximum speed of not more than 55 knots; and must have a poweroff stall speed of no more than 24 knots..
> > https://www.usua.org/Rules/faa103.htm#:~:text=To%20be%20considered%20an%20ult ralight,no%20more%20than%2024%20knots.
> >
> > In fact, there are no universal EU regulations governing ultralight aircraft - each country has its own regulations (or none at all):
> > https://ul-center.com/2016/03/09/ultralight-flying-in-east-europe-rules-regulations-and-other-important-information/
> >
> > More guidance on this regulatory issue is in:
> > https://www.easa.europa.eu/sites/default/files/dfu/03%20-%20Final%20Report%2026%20Nov%2010.pdf
> >
> > But it contains this confusing statement:
> >
> > Gliders without an engine enabling self-launch if < 450kgs (two-seat) or 300kgs
> > (single-seat) are within the scope of Community regulations. Gliders with engines
> > enabling self-launch and which are > 450 / 300kgs MTOM microlight limits are with
> > the scope of Community regulations.
> >
> > GP Gliders lists the MTOW of the GP-15 on their website at 470 kg (who knows what the final number will be), putting it well into the EU regulatory claws by 170 kg. So I don't see how they can fly underneath the EU regulatory radar as an ultralight without losing 170 kg of weight, which seems highly unlikely.
> >
> > Most gliders imported into the US in the experimental category have a type certificate in the EU. Will the FAA be more hesitant in issuing experimental airworthiness certificates to gliders that have not undergone this certification testing? We will just have to wait and see how this unfolds. To date, I do not know of any GP-15 that has been certified anywhere, although the prototype displayed at the convention had a Slovakian registration number which I have previously shown was assigned to another aircraft. Some have said that that aircraft "could" have been deregistered and, then, reassigned to the GP-15, but have produced exactly zero proof that that had occurred.
> >
> > You imply that I am a "GP hater." I take exception with this characterization - I don't "hate" GP any more or less than any other startup aircraft manufacturer. Maybe they will ultimately deliver the goods they have promised, and maybe they won't. But I do believe that anyone putting down $105,000 on an unfinished glider deserves to be told the whole truth. And "feeling" that they are on the right path does not count as truth.
> >
> > Tom
> Right after posting this I found that the EU has, indeed, raised the ultralight weight limit to 600 kg:
>
> https://flightdesign.com/easa-new-basic-regulation-600-kg-ul-aircraft/
>
> Tom

After looking up the EASA regulation, it is even more muddled (https://www.easa.europa.eu/sites/default/files/dfu/Easy_Access_Rules_for_the_Basic_Regulation.pdf):

8. A Member State may decide to exempt from this Regulation the design, production,
maintenance and operation activities in respect of one or more of the following categories of
aircraft:
(a) aeroplanes, other than unmanned aeroplanes, which have no more than two seats,
measurable stall speed or minimum steady flight speed in landing configuration not
exceeding 45 knots calibrated air speed and a maximum take-off mass (MTOM), as
recorded by the Member State, of no more than 600 kg for aeroplanes not intended to
be operated on water or 650 kg for aeroplanes intended to be operated on water;

Thus, the actual applied regulation can vary from country to country because of the word "may" in the regulation. One would have to check with every aviation authority in each country one chose to fly in.

Tom

jld

August 17th 20, 12:16 AM

Tom,
Good to see you have the patience to read the EASA publications.
Indeed as it was suggested before and I tried to explain, following this EASA 600kg UL limit change opportunity, which dates from 2 years back, national authorities have taken some time to release their updated rules for UL.
Certain countries, like Germany, are using the full option (600kg MTM/ 45kts Vso) while others, like France, are restricting to lower limits (345kg MTM/ 38kts Vso for single seat). This is part of the complexity GP had to sort out. This also means the GP15 will be allowed to fly at different maximum wing loading in function of registration country (45kg/m2 to 60kg/m2). 45 kg/m2 should still be nice when cruising below 200 km/h.
I will be able to share more details on UL national rules if people need them.

Re: experimental, in the past FAA has already approved experimental aircraft without any prior certification. I don't see any reason why this would not be possible for GP. I am sure US GP dealer has all the details.
As far as Slovak registration, the main reason to use it is because Slovak has the easiest approval process for UL in EU. Very little documentation is required. The only counter part is that you need to get a Slovak UL license to fly the aircraft, which is also easy to get. It is not uncommon at all to recycle registration and I don't see the issue.

I agree with you that people who have invested significant amounts deserve to be informed. Maybe they are, I don't know.
My experience has been more with the traditional manufacturers and I have never been thrilled with their communication!
We have yet to see clear communication from SH or JS on the number of years it takes to get delivery of a new V3 or JS3!
This is not an excuse but probably a bad habit from this whole business!

Indeed I don't have the truth but when I try to connect the dots, the near future seems promising. Q1 2021 is 6 months away and if GP is correct should show an increase in production rate and start of deliveries in EU soon after.

Regards.

August 17th 20, 04:00 AM

On Sunday, August 16, 2020 at 4:16:03 PM UTC-7, jld wrote:
> Tom,
> Good to see you have the patience to read the EASA publications.
> Indeed as it was suggested before and I tried to explain, following this EASA 600kg UL limit change opportunity, which dates from 2 years back, national authorities have taken some time to release their updated rules for UL..
> Certain countries, like Germany, are using the full option (600kg MTM/ 45kts Vso) while others, like France, are restricting to lower limits (345kg MTM/ 38kts Vso for single seat). This is part of the complexity GP had to sort out. This also means the GP15 will be allowed to fly at different maximum wing loading in function of registration country (45kg/m2 to 60kg/m2). 45 kg/m2 should still be nice when cruising below 200 km/h.
> I will be able to share more details on UL national rules if people need them.
>
> Re: experimental, in the past FAA has already approved experimental aircraft without any prior certification. I don't see any reason why this would not be possible for GP. I am sure US GP dealer has all the details.
> As far as Slovak registration, the main reason to use it is because Slovak has the easiest approval process for UL in EU. Very little documentation is required. The only counter part is that you need to get a Slovak UL license to fly the aircraft, which is also easy to get. It is not uncommon at all to recycle registration and I don't see the issue.
>
>
> I agree with you that people who have invested significant amounts deserve to be informed. Maybe they are, I don't know.
> My experience has been more with the traditional manufacturers and I have never been thrilled with their communication!
> We have yet to see clear communication from SH or JS on the number of years it takes to get delivery of a new V3 or JS3!
> This is not an excuse but probably a bad habit from this whole business!
>
> Indeed I don't have the truth but when I try to connect the dots, the near future seems promising. Q1 2021 is 6 months away and if GP is correct should show an increase in production rate and start of deliveries in EU soon after.
>
> Regards.

Thanks for the additional clarification, but your Q121 guess is just a WAG (it might be Q1, but the year is in doubt). I am firmly in the camp of "I'll believe it when I see it."

Tom

jld

August 17th 20, 05:43 AM

The Q1 2021 date is from GP website. This is in their August update.

I hope for the community that they will be in track this time.

Eric Greenwell[_4_]

August 17th 20, 03:46 PM

jld wrote on 8/16/2020 4:16 PM:
> Tom,
> Good to see you have the patience to read the EASA publications.
> Indeed as it was suggested before and I tried to explain, following this EASA 600kg UL limit change opportunity, which dates from 2 years back, national authorities have taken some time to release their updated rules for UL.
> Certain countries, like Germany, are using the full option (600kg MTM/ 45kts Vso) while others, like France, are restricting to lower limits (345kg MTM/ 38kts Vso for single seat). This is part of the complexity GP had to sort out. This also means the GP15 will be allowed to fly at different maximum wing loading in function of registration country (45kg/m2 to 60kg/m2). 45 kg/m2 should still be nice when cruising below 200 km/h.
> I will be able to share more details on UL national rules if people need them.
>
> Re: experimental, in the past FAA has already approved experimental aircraft without any prior certification. I don't see any reason why this would not be possible for GP. I am sure US GP dealer has all the details.
> As far as Slovak registration, the main reason to use it is because Slovak has the easiest approval process for UL in EU. Very little documentation is required. The only counter part is that you need to get a Slovak UL license to fly the aircraft, which is also easy to get. It is not uncommon at all to recycle registration and I don't see the issue.
>
>
> I agree with you that people who have invested significant amounts deserve to be informed. Maybe they are, I don't know.
> My experience has been more with the traditional manufacturers and I have never been thrilled with their communication!
> We have yet to see clear communication from SH or JS on the number of years it takes to get delivery of a new V3 or JS3!
> This is not an excuse but probably a bad habit from this whole business!
>
> Indeed I don't have the truth but when I try to connect the dots, the near future seems promising. Q1 2021 is 6 months away and if GP is correct should show an increase in production rate and start of deliveries in EU soon after.

Thanks for the remarks. I now understand how the GP15 went from 475 kg MTOW in the
early brochures to 600 Kg a few months ago. I think 500 kg (65 kg/m2 or 13.25
lbs/ft2) is the highest useful weight for all but extreme conditions. I've never
encountered those, but perhaps eastern ridge runners or western wave flyers might.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications/download-the-guide-1

kinsell

August 17th 20, 08:51 PM

On 8/16/20 5:16 PM, jld wrote:

> Indeed I don't have the truth but when I try to connect the dots, the near future seems promising. Q1 2021 is 6 months away and if GP is correct should show an increase in production rate and start of deliveries in EU soon after.
>

Unfortunately, this doesn't cover "fool me twenty-seven times . . ."

https://www.youtube.com/watch?v=al2z7t3M9Og

How can they increase their production rate? They haven't stabilized
the design, they're still trying to figure out how to deliver on the
amazing promises they've made.

Eric Greenwell[_4_]

August 17th 20, 09:46 PM

kinsell wrote on 8/17/2020 12:51 PM:
> On 8/16/20 5:16 PM, jld wrote:
>
>> Indeed I don't have the truth but when I try to connect the dots, the near
>> future seems promising. Q1 2021 is 6 months away and if GP is correct should
>> show an increase in production rate and start of deliveries in EU soon after.
>>
>
> Unfortunately, this doesn't cover "fool me twenty-seven times . . ."
>
> https://www.youtube.com/watch?v=al2z7t3M9Og
>
> How can they increase their production rate?* They haven't stabilized the design,
> they're still trying to figure out how to deliver on the amazing promises they've
> made.

The latest (Aug 2020) published remarks on the situation are on the GP website at

https://www.gpgliders.com/news/project-update-august

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications/download-the-guide-1

August 18th 20, 05:20 AM

On Monday, August 17, 2020 at 1:46:17 PM UTC-7, Eric Greenwell wrote:
> kinsell wrote on 8/17/2020 12:51 PM:
> > On 8/16/20 5:16 PM, jld wrote:
> >
> >> Indeed I don't have the truth but when I try to connect the dots, the near
> >> future seems promising. Q1 2021 is 6 months away and if GP is correct should
> >> show an increase in production rate and start of deliveries in EU soon after.
> >>
> >
> > Unfortunately, this doesn't cover "fool me twenty-seven times . . ."
> >
> > https://www.youtube.com/watch?v=al2z7t3M9Og
> >
> > How can they increase their production rate? They haven't stabilized the design,
> > they're still trying to figure out how to deliver on the amazing promises they've
> > made.
> The latest (Aug 2020) published remarks on the situation are on the GP website at
>
> https://www.gpgliders.com/news/project-update-august
> --
> Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
> - "A Guide to Self-Launching Sailplane Operation"
> https://sites.google.com/site/motorgliders/publications/download-the-guide-1

"We expect to freeze the general design of the GP 14 VELO and GP 15 JETA in Q1 2021"

That means no production will begin until AFTER Q1 2021 - at the earliest. "Expect" is a non-committal word, as opposed to "will." Also, the weight change from 450kg to 600kg clearly wasn't design driven, but regulatory driven, meaning it can't be relied upon.

Tom

Eric Greenwell[_4_]

August 18th 20, 01:35 PM

2G wrote on 8/17/2020 9:20 PM:
> On Monday, August 17, 2020 at 1:46:17 PM UTC-7, Eric Greenwell wrote:
>> kinsell wrote on 8/17/2020 12:51 PM:
>>> On 8/16/20 5:16 PM, jld wrote:
>>>
>>>> Indeed I don't have the truth but when I try to connect the dots, the near
>>>> future seems promising. Q1 2021 is 6 months away and if GP is correct should
>>>> show an increase in production rate and start of deliveries in EU soon after.
>>>>
>>>
>>> Unfortunately, this doesn't cover "fool me twenty-seven times . . ."
>>>
>>> https://www.youtube.com/watch?v=al2z7t3M9Og
>>>
>>> How can they increase their production rate? They haven't stabilized the design,
>>> they're still trying to figure out how to deliver on the amazing promises they've
>>> made.
>> The latest (Aug 2020) published remarks on the situation are on the GP website at
>>
>> https://www.gpgliders.com/news/project-update-august
>> --
>> Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
>> - "A Guide to Self-Launching Sailplane Operation"
>> https://sites.google.com/site/motorgliders/publications/download-the-guide-1
>
> "We expect to freeze the general design of the GP 14 VELO and GP 15 JETA in Q1 2021"
>
> That means no production will begin until AFTER Q1 2021 - at the earliest. "Expect" is a non-committal word, as opposed to "will." Also, the weight change from 450kg to 600kg clearly wasn't design driven, but regulatory driven, meaning it can't be relied upon.

Two gliders are in production, two gliders are being updated for their owners,
according to factory remarks a few weeks ago.

Why do you say their published specifications can not be relied on? Surely, they
could design to a higher weight, but claim the lower weight to simplify licensing
for test flying and advertising purposes, while waiting for the new regulations?
That would be sensible response when you know regulations are going to change, but
the timing and details aren't known.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications/download-the-guide-1

jld

August 18th 20, 04:41 PM

You probably have reasons to be skeptical but, they should only "expect" until the validation (ground/flight tests) are performed and don't force design changes.
If they updated their configuration this year, it makes sense for the validation tests to happen in Q1 next year.
Because this is not a complete redesign, they should be confident enough to pass validation tests and take the risk to start production using new configuration right now. Therefore I am not surprised to hear they are updating already produced gliders and produce new ones with latest configuration.

"wasn't design driven, but regulatory driven, meaning it can't be relied upon"
I don't get your point, the same situation would be true for anybody designing under FAA/EASA or UL. Until you apply for TC, if authorities changes the rules, you have to adjust.
The UL regulation changes in EU took a long time to get delivered and I am confident it is going to be stable for quite a bit of time.
GP did their best to come up with design targets and now they adjust them to fit most authorities requirements.

Concerning the MTM, if the structure is not the limiting factor, GP will eventually have to adjust it to pass the Vso requirement for UL in EU (i.e. 45 Kts for Germany and 38 Kts in France).
If structure is capable, US experimental could use a higher MTM but, who want to fly above 60 kg/m2 anyway?

Eric Greenwell[_4_]

August 18th 20, 05:08 PM

jld wrote on 8/18/2020 8:41 AM:

> If structure is capable, US experimental could use a higher MTM but, who want to fly above 60 kg/m2 anyway?

Glider pilots on the Allegheny Ridges (ridge soaring), in Western US high deserts
(thermal soaring), and in the Sierra wave sometimes use higher wing loadings. For
my flying in the US, I expect 60 kg/m2 will be plenty high enough, and far above
the 42 kg/m2 (8.5 lb/ft2) I fly at in my ASH26E.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications/download-the-guide-1

jld

August 18th 20, 05:57 PM

"Glider pilots on the Allegheny Ridges (ridge soaring), in Western US high deserts (thermal soaring), and in the Sierra wave sometimes use higher wing loading"

Then the GP15 might be able to satisfy these US pilots as long as they use antifreeze in the ballast :-).
Also you might not be able to get all the benefits of high WL if you are limited by Vne due to high altitude.

I have been lucky to fly in Minden before.
Unless you compete in the WGC or are trying to beat a world record, 60 kg/m2 would already be A lot.

Bottom line, lets look for news from GP or the dealers to get confirmation of configuration and delivery dates...

Eric Greenwell[_4_]

August 18th 20, 06:38 PM

jld wrote on 8/18/2020 9:57 AM:
>
> "Glider pilots on the Allegheny Ridges (ridge soaring), in Western US high deserts (thermal soaring), and in the Sierra wave sometimes use higher wing loading"
>
> Then the GP15 might be able to satisfy these US pilots as long as they use antifreeze in the ballast :-).
> Also you might not be able to get all the benefits of high WL if you are limited by Vne due to high altitude.
>
> I have been lucky to fly in Minden before.
> Unless you compete in the WGC or are trying to beat a world record, 60 kg/m2 would already be A lot.
>
> Bottom line, lets look for news from GP or the dealers to get confirmation of configuration and delivery dates...

No antifreeze needed in the summer, as the temperatures at 18,000' are not cold
enough to freeze the water in the wings. Winter wave flying is much colder, of
course, and wave runners that get permission to fly above 18,000' have to consider
the temperature at any time of the year.

According to the recent provisional manual, the GP15 VNE is 162 kts IAS up to 3000
meters; 143 kts IAS at 6000 meters. That's about 195 kts TAS from 3000 meter on
up, so a pretty high limit, especially compared to my ASH26E, with it's 143 kt
VNE. I don't know what modern gliders have for VNE, or wing loading, for that matter.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications/download-the-guide-1

andy l

August 18th 20, 09:49 PM

On Tuesday, 18 August 2020 at 16:41:21 UTC+1, jld wrote:
> You probably have reasons to be skeptical but, they should only "expect" until the validation (ground/flight tests) are performed and don't force design changes.
> If they updated their configuration this year, it makes sense for the validation tests to happen in Q1 next year.
> Because this is not a complete redesign, they should be confident enough to pass validation tests and take the risk to start production using new configuration right now. Therefore I am not surprised to hear they are updating already produced gliders and produce new ones with latest configuration.
> "wasn't design driven, but regulatory driven, meaning it can't be relied upon"
> I don't get your point, the same situation would be true for anybody designing under FAA/EASA or UL. Until you apply for TC, if authorities changes the rules, you have to adjust.
> The UL regulation changes in EU took a long time to get delivered and I am confident it is going to be stable for quite a bit of time.
> GP did their best to come up with design targets and now they adjust them to fit most authorities requirements.
>
> Concerning the MTM, if the structure is not the limiting factor, GP will eventually have to adjust it to pass the Vso requirement for UL in EU (i.e. 45 Kts for Germany and 38 Kts in France).
> If structure is capable, US experimental could use a higher MTM but, who want to fly above 60 kg/m2 anyway?

Adding together some of the recent comments, it sounds like this glider might be stronger and lighter than others, and possibly faster as well

Does it use different materials?

And what are all the changes? You can't easily modify already existing gliders for a much higher all up weight, just by writing it down somewhere; it needs to be stronger, for instance thicker spar caps

andy l

August 18th 20, 10:00 PM

On Monday, 17 August 2020 at 00:16:03 UTC+1, jld wrote:
> We have yet to see clear communication from SH or JS on the number of years it takes to get delivery of a new V3 or JS3!
> This is not an excuse but probably a bad habit from this whole business!
>
Who are the 'we' in this remark? Have you made such enquiries yourself?

These gliders have been in production for a while. Some friends have received theirs, so it isn't hard to figure out their effective delivery times. Going forward, the other day I heard some current info on likely timing for new Ventus orders. It doesn't seem to be a state secret.

August 18th 20, 11:07 PM

On Tuesday, August 18, 2020 at 1:49:35 PM UTC-7, andy l wrote:
> On Tuesday, 18 August 2020 at 16:41:21 UTC+1, jld wrote:
> > You probably have reasons to be skeptical but, they should only "expect" until the validation (ground/flight tests) are performed and don't force design changes.
> > If they updated their configuration this year, it makes sense for the validation tests to happen in Q1 next year.
> > Because this is not a complete redesign, they should be confident enough to pass validation tests and take the risk to start production using new configuration right now. Therefore I am not surprised to hear they are updating already produced gliders and produce new ones with latest configuration.
> > "wasn't design driven, but regulatory driven, meaning it can't be relied upon"
> > I don't get your point, the same situation would be true for anybody designing under FAA/EASA or UL. Until you apply for TC, if authorities changes the rules, you have to adjust.
> > The UL regulation changes in EU took a long time to get delivered and I am confident it is going to be stable for quite a bit of time.
> > GP did their best to come up with design targets and now they adjust them to fit most authorities requirements.
> >
> > Concerning the MTM, if the structure is not the limiting factor, GP will eventually have to adjust it to pass the Vso requirement for UL in EU (i.e. 45 Kts for Germany and 38 Kts in France).
> > If structure is capable, US experimental could use a higher MTM but, who want to fly above 60 kg/m2 anyway?
> Adding together some of the recent comments, it sounds like this glider might be stronger and lighter than others, and possibly faster as well
>
> Does it use different materials?
>
> And what are all the changes? You can't easily modify already existing gliders for a much higher all up weight, just by writing it down somewhere; it needs to be stronger, for instance thicker spar caps

They claim to use different materials that make GP gliders lighter and stronger than the competition:

"We use the most advanced composites and construction methods that allow for the exceptional strength requirements of the design. They also contribute to the quality and reliability of the structure. This allows gliders of far lower weight to be as strong as gliders produced using conventional methods."

GP doesn't just claim "lower weight," but "far lower weight" than other gliders, but w/o any evidence to support this claim. The only real evidence I have seen is that Sebastian Kawa was very unhappy with the glider GP delivered to him and switched gliders at the last minute. Kawa also had a propulsion failure while flying a GP-14 in Italy, yet GP gliders makes this bizarre claim on their website:

"The motor can be deployed and running at full power within five seconds providing confidence in the event of when a â€˜low saveâ€™ is on the cards."

I guess Sebastian didn't get the memo on how reliable GP propulsion systems are. You are certainly welcome to accept all of GP's claims w/o any evidence, but I won't. And I certainly wouldn't send them six figures in cash for it.

Tom

[email protected]

August 18th 20, 11:54 PM

On Tuesday, August 18, 2020 at 10:39:00 AM UTC-7, Eric Greenwell wrote:
> jld wrote on 8/18/2020 9:57 AM:
> >
> > "Glider pilots on the Allegheny Ridges (ridge soaring), in Western US high deserts (thermal soaring), and in the Sierra wave sometimes use higher wing loading"
> >
> > Then the GP15 might be able to satisfy these US pilots as long as they use antifreeze in the ballast :-).
> > Also you might not be able to get all the benefits of high WL if you are limited by Vne due to high altitude.
> >
> > I have been lucky to fly in Minden before.
> > Unless you compete in the WGC or are trying to beat a world record, 60 kg/m2 would already be A lot.
> >
> > Bottom line, lets look for news from GP or the dealers to get confirmation of configuration and delivery dates...
>
> No antifreeze needed in the summer, as the temperatures at 18,000' are not cold
> enough to freeze the water in the wings. Winter wave flying is much colder, of
> course, and wave runners that get permission to fly above 18,000' have to consider
> the temperature at any time of the year.
>
> According to the recent provisional manual, the GP15 VNE is 162 kts IAS up to 3000
> meters; 143 kts IAS at 6000 meters. That's about 195 kts TAS from 3000 meter on
> up, so a pretty high limit, especially compared to my ASH26E, with it's 143 kt
> VNE. I don't know what modern gliders have for VNE, or wing loading, for that matter.
>
>
> --
> Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
> - "A Guide to Self-Launching Sailplane Operation"
> https://sites.google.com/site/motorgliders/publications/download-the-guide-1

Eric, what air temp do you regard as cold enough to freeze water in the wings?

kinsell

August 19th 20, 12:01 AM

On 8/18/20 4:07 PM, 2G wrote:
> On Tuesday, August 18, 2020 at 1:49:35 PM UTC-7, andy l wrote:
>> On Tuesday, 18 August 2020 at 16:41:21 UTC+1, jld wrote:
>>> You probably have reasons to be skeptical but, they should only "expect" until the validation (ground/flight tests) are performed and don't force design changes.
>>> If they updated their configuration this year, it makes sense for the validation tests to happen in Q1 next year.
>>> Because this is not a complete redesign, they should be confident enough to pass validation tests and take the risk to start production using new configuration right now. Therefore I am not surprised to hear they are updating already produced gliders and produce new ones with latest configuration.
>>> "wasn't design driven, but regulatory driven, meaning it can't be relied upon"
>>> I don't get your point, the same situation would be true for anybody designing under FAA/EASA or UL. Until you apply for TC, if authorities changes the rules, you have to adjust.
>>> The UL regulation changes in EU took a long time to get delivered and I am confident it is going to be stable for quite a bit of time.
>>> GP did their best to come up with design targets and now they adjust them to fit most authorities requirements.
>>>
>>> Concerning the MTM, if the structure is not the limiting factor, GP will eventually have to adjust it to pass the Vso requirement for UL in EU (i.e. 45 Kts for Germany and 38 Kts in France).
>>> If structure is capable, US experimental could use a higher MTM but, who want to fly above 60 kg/m2 anyway?
>> Adding together some of the recent comments, it sounds like this glider might be stronger and lighter than others, and possibly faster as well
>>
>> Does it use different materials?
>>
>> And what are all the changes? You can't easily modify already existing gliders for a much higher all up weight, just by writing it down somewhere; it needs to be stronger, for instance thicker spar caps
>
> They claim to use different materials that make GP gliders lighter and stronger than the competition:
>
> "We use the most advanced composites and construction methods that allow for the exceptional strength requirements of the design. They also contribute to the quality and reliability of the structure. This allows gliders of far lower weight to be as strong as gliders produced using conventional methods."
>
> GP doesn't just claim "lower weight," but "far lower weight" than other gliders, but w/o any evidence to support this claim. The only real evidence I have seen is that Sebastian Kawa was very unhappy with the glider GP delivered to him and switched gliders at the last minute. Kawa also had a propulsion failure while flying a GP-14 in Italy, yet GP gliders makes this bizarre claim on their website:
>
> "The motor can be deployed and running at full power within five seconds providing confidence in the event of when a â€˜low saveâ€™ is on the cards."
>
> I guess Sebastian didn't get the memo on how reliable GP propulsion systems are. You are certainly welcome to accept all of GP's claims w/o any evidence, but I won't. And I certainly wouldn't send them six figures in cash for it.
>
> Tom
>
>
Sebastian's disinterest in flying the Jeta in 2018 was addressed in the
November Soaring article. The wings weren't adequately cured and sagged
fore and aft of the spars. These same wings were what the U.S. dealer
test flew for the article. Putting his best spin on it, he said 51:1
remains a reasonable goal for the small fuselage version. Not exactly
the same as a Dick Johnson test report.

On the propulsion failure, Eric has claimed it was pilot error. If it's
too complicated for a world-class pilot to get right, maybe it needs to
be simplified? "Alexa, save my ass!!"

Sebastian for his part hasn't admitted to error, he made it sound like a
sensor failure indicating the boom wasn't fully up, as can happen on any
boom system. He did press on from an area with good landing options
when getting low to one with poor options, so there was a judgement
error there.

-Dave

August 19th 20, 01:45 AM

On Tuesday, August 18, 2020 at 4:01:47 PM UTC-7, kinsell wrote:
> On 8/18/20 4:07 PM, 2G wrote:
> > On Tuesday, August 18, 2020 at 1:49:35 PM UTC-7, andy l wrote:
> >> On Tuesday, 18 August 2020 at 16:41:21 UTC+1, jld wrote:
> >>> You probably have reasons to be skeptical but, they should only "expect" until the validation (ground/flight tests) are performed and don't force design changes.
> >>> If they updated their configuration this year, it makes sense for the validation tests to happen in Q1 next year.
> >>> Because this is not a complete redesign, they should be confident enough to pass validation tests and take the risk to start production using new configuration right now. Therefore I am not surprised to hear they are updating already produced gliders and produce new ones with latest configuration.
> >>> "wasn't design driven, but regulatory driven, meaning it can't be relied upon"
> >>> I don't get your point, the same situation would be true for anybody designing under FAA/EASA or UL. Until you apply for TC, if authorities changes the rules, you have to adjust.
> >>> The UL regulation changes in EU took a long time to get delivered and I am confident it is going to be stable for quite a bit of time.
> >>> GP did their best to come up with design targets and now they adjust them to fit most authorities requirements.
> >>>
> >>> Concerning the MTM, if the structure is not the limiting factor, GP will eventually have to adjust it to pass the Vso requirement for UL in EU (i.e. 45 Kts for Germany and 38 Kts in France).
> >>> If structure is capable, US experimental could use a higher MTM but, who want to fly above 60 kg/m2 anyway?
> >> Adding together some of the recent comments, it sounds like this glider might be stronger and lighter than others, and possibly faster as well
> >>
> >> Does it use different materials?
> >>
> >> And what are all the changes? You can't easily modify already existing gliders for a much higher all up weight, just by writing it down somewhere; it needs to be stronger, for instance thicker spar caps
> >
> > They claim to use different materials that make GP gliders lighter and stronger than the competition:
> >
> > "We use the most advanced composites and construction methods that allow for the exceptional strength requirements of the design. They also contribute to the quality and reliability of the structure. This allows gliders of far lower weight to be as strong as gliders produced using conventional methods."
> >
> > GP doesn't just claim "lower weight," but "far lower weight" than other gliders, but w/o any evidence to support this claim. The only real evidence I have seen is that Sebastian Kawa was very unhappy with the glider GP delivered to him and switched gliders at the last minute. Kawa also had a propulsion failure while flying a GP-14 in Italy, yet GP gliders makes this bizarre claim on their website:
> >
> > "The motor can be deployed and running at full power within five seconds providing confidence in the event of when a â€˜low saveâ€™ is on the cards."
> >
> > I guess Sebastian didn't get the memo on how reliable GP propulsion systems are. You are certainly welcome to accept all of GP's claims w/o any evidence, but I won't. And I certainly wouldn't send them six figures in cash for it.
> >
> > Tom
> >
> >
> Sebastian's disinterest in flying the Jeta in 2018 was addressed in the
> November Soaring article. The wings weren't adequately cured and sagged
> fore and aft of the spars. These same wings were what the U.S. dealer
> test flew for the article. Putting his best spin on it, he said 51:1
> remains a reasonable goal for the small fuselage version. Not exactly
> the same as a Dick Johnson test report.
>
> On the propulsion failure, Eric has claimed it was pilot error. If it's
> too complicated for a world-class pilot to get right, maybe it needs to
> be simplified? "Alexa, save my ass!!"
>
> Sebastian for his part hasn't admitted to error, he made it sound like a
> sensor failure indicating the boom wasn't fully up, as can happen on any
> boom system. He did press on from an area with good landing options
> when getting low to one with poor options, so there was a judgement
> error there.
>
> -Dave

Ok, let's blame the victim here. GP delivered a poorly constructed glider to Kawa - maybe that's Kawa's fault as well. AFAIK, no GP-15s have received airworthiness certificates in the US (or elsewhere for that matter). The point is that the very limited quality control data we have on GP Gliders is not encouraging, and their wild advertising claims are unsupported.

Tom

Eric Greenwell[_4_]

August 19th 20, 03:06 AM

wrote on 8/18/2020 3:54 PM:
> On Tuesday, August 18, 2020 at 10:39:00 AM UTC-7, Eric Greenwell wrote:
>> jld wrote on 8/18/2020 9:57 AM:
>>>
>>> "Glider pilots on the Allegheny Ridges (ridge soaring), in Western US high deserts (thermal soaring), and in the Sierra wave sometimes use higher wing loading"
>>>
>>> Then the GP15 might be able to satisfy these US pilots as long as they use antifreeze in the ballast :-).
>>> Also you might not be able to get all the benefits of high WL if you are limited by Vne due to high altitude.
>>>
>>> I have been lucky to fly in Minden before.
>>> Unless you compete in the WGC or are trying to beat a world record, 60 kg/m2 would already be A lot.
>>>
>>> Bottom line, lets look for news from GP or the dealers to get confirmation of configuration and delivery dates...
>>
>> No antifreeze needed in the summer, as the temperatures at 18,000' are not cold
>> enough to freeze the water in the wings. Winter wave flying is much colder, of
>> course, and wave runners that get permission to fly above 18,000' have to consider
>> the temperature at any time of the year.
>>
>> According to the recent provisional manual, the GP15 VNE is 162 kts IAS up to 3000
>> meters; 143 kts IAS at 6000 meters. That's about 195 kts TAS from 3000 meter on
>> up, so a pretty high limit, especially compared to my ASH26E, with it's 143 kt
>> VNE. I don't know what modern gliders have for VNE, or wing loading, for that matter.
>>

>
> Eric, what air temp do you regard as cold enough to freeze water in the wings?

The situation I mentioned - summer in high desert areas - means ground elevations
of 5000' or more, and with ground temperatures of 90+, it will be 25 deg F at
18,000. With the ups and downs of thermal flying, the average temperature will be
around freezing, so the water ballast won't be cold enough long enough to freeze.

For other situations, I really don't know. In thermal conditions, I wouldn't worry
unless the minimum temperature went below 20 deg F. Perhaps a temperature meter
with a remote probe in the wing tank is the safest thing. The glider handbook may
have guidance, too. A wireless sensor might be easiest to use for the wing

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications/download-the-guide-1

Eric Greenwell[_4_]

August 19th 20, 03:26 AM

2G wrote on 8/18/2020 3:07 PM:
> On Tuesday, August 18, 2020 at 1:49:35 PM UTC-7, andy l wrote:
>> On Tuesday, 18 August 2020 at 16:41:21 UTC+1, jld wrote:
>>> You probably have reasons to be skeptical but, they should only "expect" until the validation (ground/flight tests) are performed and don't force design changes.
>>> If they updated their configuration this year, it makes sense for the validation tests to happen in Q1 next year.
>>> Because this is not a complete redesign, they should be confident enough to pass validation tests and take the risk to start production using new configuration right now. Therefore I am not surprised to hear they are updating already produced gliders and produce new ones with latest configuration.
>>> "wasn't design driven, but regulatory driven, meaning it can't be relied upon"
>>> I don't get your point, the same situation would be true for anybody designing under FAA/EASA or UL. Until you apply for TC, if authorities changes the rules, you have to adjust.
>>> The UL regulation changes in EU took a long time to get delivered and I am confident it is going to be stable for quite a bit of time.
>>> GP did their best to come up with design targets and now they adjust them to fit most authorities requirements.
>>>
>>> Concerning the MTM, if the structure is not the limiting factor, GP will eventually have to adjust it to pass the Vso requirement for UL in EU (i.e. 45 Kts for Germany and 38 Kts in France).
>>> If structure is capable, US experimental could use a higher MTM but, who want to fly above 60 kg/m2 anyway?
>> Adding together some of the recent comments, it sounds like this glider might be stronger and lighter than others, and possibly faster as well
>>
>> Does it use different materials?
>>
>> And what are all the changes? You can't easily modify already existing gliders for a much higher all up weight, just by writing it down somewhere; it needs to be stronger, for instance thicker spar caps
>
> They claim to use different materials that make GP gliders lighter and stronger than the competition:
>
> "We use the most advanced composites and construction methods that allow for the exceptional strength requirements of the design. They also contribute to the quality and reliability of the structure. This allows gliders of far lower weight to be as strong as gliders produced using conventional methods."
>
> GP doesn't just claim "lower weight," but "far lower weight" than other gliders, but w/o any evidence to support this claim. The only real evidence I have seen is that Sebastian Kawa was very unhappy with the glider GP delivered to him and switched gliders at the last minute. Kawa also had a propulsion failure while flying a GP-14 in Italy, yet GP gliders makes this bizarre claim on their website:
>
> "The motor can be deployed and running at full power within five seconds providing confidence in the event of when a â€˜low saveâ€™ is on the cards."
>
> I guess Sebastian didn't get the memo on how reliable GP propulsion systems are. You are certainly welcome to accept all of GP's claims w/o any evidence, but I won't. And I certainly wouldn't send them six figures in cash for it.

The motor can indeed be deployed and running in 5 seconds, and with considerable
confidence. The original mechanical mast switch, external to the mast, was deemed
too vulnerable to damage after Kawa's accident with the prototype glider. It was
replaced with two redundant, buried solid state switches to prevent a repeat of
the problem. You've had a similar switch failure on your Schleicher glider, but
were lucky that it eventually worked after repeated attempts. Other Schleicher
owners have also experienced mast switch failures, but Schleicher still uses the
external mechanical switches. Maybe they didn't get the memo?

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications/download-the-guide-1

Eric Greenwell[_4_]

August 19th 20, 04:49 AM

kinsell wrote on 8/18/2020 4:01 PM:
> On the propulsion failure, Eric has claimed it was pilot error.* If it's too
> complicated for a world-class pilot to get right, maybe it needs to be
> simplified?* "Alexa, save my ass!!"

I did not claim the propulsion system failed due to pilot error (flying out of
reach of a good landing field). I said the accident was due to pilot error, which
Kawa has acknowledged.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications/download-the-guide-1

August 19th 20, 06:10 AM

On Tuesday, August 18, 2020 at 7:26:51 PM UTC-7, Eric Greenwell wrote:
> 2G wrote on 8/18/2020 3:07 PM:
> > On Tuesday, August 18, 2020 at 1:49:35 PM UTC-7, andy l wrote:
> >> On Tuesday, 18 August 2020 at 16:41:21 UTC+1, jld wrote:
> >>> You probably have reasons to be skeptical but, they should only "expect" until the validation (ground/flight tests) are performed and don't force design changes.
> >>> If they updated their configuration this year, it makes sense for the validation tests to happen in Q1 next year.
> >>> Because this is not a complete redesign, they should be confident enough to pass validation tests and take the risk to start production using new configuration right now. Therefore I am not surprised to hear they are updating already produced gliders and produce new ones with latest configuration.
> >>> "wasn't design driven, but regulatory driven, meaning it can't be relied upon"
> >>> I don't get your point, the same situation would be true for anybody designing under FAA/EASA or UL. Until you apply for TC, if authorities changes the rules, you have to adjust.
> >>> The UL regulation changes in EU took a long time to get delivered and I am confident it is going to be stable for quite a bit of time.
> >>> GP did their best to come up with design targets and now they adjust them to fit most authorities requirements.
> >>>
> >>> Concerning the MTM, if the structure is not the limiting factor, GP will eventually have to adjust it to pass the Vso requirement for UL in EU (i.e. 45 Kts for Germany and 38 Kts in France).
> >>> If structure is capable, US experimental could use a higher MTM but, who want to fly above 60 kg/m2 anyway?
> >> Adding together some of the recent comments, it sounds like this glider might be stronger and lighter than others, and possibly faster as well
> >>
> >> Does it use different materials?
> >>
> >> And what are all the changes? You can't easily modify already existing gliders for a much higher all up weight, just by writing it down somewhere; it needs to be stronger, for instance thicker spar caps
> >
> > They claim to use different materials that make GP gliders lighter and stronger than the competition:
> >
> > "We use the most advanced composites and construction methods that allow for the exceptional strength requirements of the design. They also contribute to the quality and reliability of the structure. This allows gliders of far lower weight to be as strong as gliders produced using conventional methods."
> >
> > GP doesn't just claim "lower weight," but "far lower weight" than other gliders, but w/o any evidence to support this claim. The only real evidence I have seen is that Sebastian Kawa was very unhappy with the glider GP delivered to him and switched gliders at the last minute. Kawa also had a propulsion failure while flying a GP-14 in Italy, yet GP gliders makes this bizarre claim on their website:
> >
> > "The motor can be deployed and running at full power within five seconds providing confidence in the event of when a â€˜low saveâ€™ is on the cards."
> >
> > I guess Sebastian didn't get the memo on how reliable GP propulsion systems are. You are certainly welcome to accept all of GP's claims w/o any evidence, but I won't. And I certainly wouldn't send them six figures in cash for it.
> The motor can indeed be deployed and running in 5 seconds, and with considerable
> confidence. The original mechanical mast switch, external to the mast, was deemed
> too vulnerable to damage after Kawa's accident with the prototype glider. It was
> replaced with two redundant, buried solid state switches to prevent a repeat of
> the problem. You've had a similar switch failure on your Schleicher glider, but
> were lucky that it eventually worked after repeated attempts. Other Schleicher
> owners have also experienced mast switch failures, but Schleicher still uses the
> external mechanical switches. Maybe they didn't get the memo?
> --
> Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
> - "A Guide to Self-Launching Sailplane Operation"
> https://sites.google.com/site/motorgliders/publications/download-the-guide-1

I DIDN'T have a similar failure - in fact, I had no failure at all. The switch was in perfect working order, the only explanation was flying a little too fast for the mast to deploy fully. In any event, this has NOTHING to do with the outrageous claims being made by GP Gliders. No one should depend upon propulsion to start in an emergency.

Tom

krasw

August 19th 20, 08:32 AM

On Tuesday, 18 August 2020 at 18:41:21 UTC+3, jld wrote:
> I don't get your point, the same situation would be true for anybody designing under FAA/EASA or UL. Until you apply for TC, if authorities changes the rules, you have to adjust.
> The UL regulation changes in EU took a long time to get delivered and I am confident it is going to be stable for quite a bit of time.
> GP did their best to come up with design targets and now they adjust them to fit most authorities requirements.
>

Once again, there are no EASA rules regulating UL. EASA simply states that you can build UL if the MTOM of the aircraft is 450 kg (plus 22,5 kg for rocket parachute, if installed), and few years back the decided to increase this limit to 600 kg. It is up to national authorities to decide what the mass limit is, this is being done currently in many countries. Mass increase created zero new regulations or design changes to follow for GP. Everything they designed in early 2010's is valid today.

Now why would you build an UL glider instead of real EASA regulated glider? Answer is simple, you don't have to go trough type certification process. You can design and build a glider-shaped object that does not conform to CS specs, and sell it anyway. You can also say that MTOM of GP15 is 470 kg and forget to tell that many European national UL rules gives MTOM for SINGLE SEAT aircraft as 315 kg. Meaning that you will eat only salad if you wan't to legally fly one. But luckily they have found at least one country overlooking this, thus the OM-register in prototypes.

jld

August 19th 20, 10:04 AM

Le mardi 18 aoÃ»t 2020 23:00:36 UTC+2, andy l a Ã©critÂ*:
> On Monday, 17 August 2020 at 00:16:03 UTC+1, jld wrote:
> > We have yet to see clear communication from SH or JS on the number of years it takes to get delivery of a new V3 or JS3!
> > This is not an excuse but probably a bad habit from this whole business!
> >
> Who are the 'we' in this remark? Have you made such enquiries yourself?
>
> These gliders have been in production for a while. Some friends have received theirs, so it isn't hard to figure out their effective delivery times. Going forward, the other day I heard some current info on likely timing for new Ventus orders. It doesn't seem to be a state secret.

Yes I am considering a V3M to replace a V2CM but the number of years is discouraging.

My only point is that companies don't advertise their backlog or delays, period.

jld

August 19th 20, 10:28 AM

"And what are all the changes? You can't easily modify already existing gliders for a much higher all up weight, just by writing it down somewhere; it needs to be stronger, for instance thicker spar caps"

Maybe the goal is not to strengthen the glider but to manage empty weight to make sure minimum operational WL is reasonable (i.e. < 45 kg/m2).

jld

August 19th 20, 11:01 AM

""GP doesn't just claim "lower weight," but "far lower weight" than other gliders, but w/o any evidence to support this claim""

The evidences are in the design and certification choices.

GP15 is about same empty weight as the H301 which was a fiberglass ship, so there is nothing new. Carbon now allows to use lower relative thickness airfoil and higher aspect ratio wings to get to higher performance.

Certification requirements have forced manufacturers to significantly increase the weight of their gliders (e.g. cockpit protection). Because more recent airfoils are tolerant to higher WL, this has not been a significant issue, except for the fact MTM goes up and self launchers need more power!
By using experimental in US and UL in EU, GP has more design freedom. For example, not proposing a heavy 16G cockpit but a rescue parachute instead!

jld

August 19th 20, 12:50 PM

"Once again, there are no EASA rules regulating UL. ... Mass increase created zero new regulations or design changes to follow for GP. Everything they designed in early 2010's is valid today."
Maybe you did not read the messages in details but the fact EASA has changed the rules concerning the weight under which the EU nations can decide (now 600kg), has a direct effect on National UL rules!
As you probably know, several countries have come with updated rules (e.g. Germany and France). More will follow, probably mimicking the previous.
Because all countries don't use the same weight limits, this has forced GP to make adjustments to their weights (empty/max) in order to comply with the new UL rules from the different nations.
This indeed means that you will have different MTOM in function of the country of registration.
Still, even if you register in a country like France which did not take the full advantage of EASA max weight option, I am sure a lot of people would be happy to fly a GP15 up to 45 kg/m2 WL (i.e. 345kg MTOM). And no need to eat salad if you can fit in a 100kg payload :-)

"Now why would you build an UL glider instead of real EASA regulated glider?"
Certainly to avoid the high cost but also get rid of design constraints which are questionable and drive empty weight up.

"But luckily they have found at least one country overlooking this, thus the OM-register in prototypes"
You are probably not from Slovakia to make such a hard statement.
In most EU countries, UL rules are rather relaxed and the authorities rely on manufacturers and operators responsibility.
Slovakia (OM) is such a country which makes the process of registering and operating an UL easy. This is an upside and would be nice if more countries would follow.

krasw

August 19th 20, 01:36 PM

On Wednesday, 19 August 2020 at 14:50:57 UTC+3, jld wrote:
> Because all countries don't use the same weight limits, this has forced GP to make adjustments to their weights (empty/max) in order to comply with the new UL rules from the different nations.

No they don't. You have a 470kg glider in UL class that has MTOM of 472,5 kg (if national regs allow). Now EASA says that you can design and build an UL aircraft that has MTOM of 600kg (if national regs allow). The 470 kg GP fits into that weight limit perfectly.

> Slovakia (OM) is such a country which makes the process of registering and operating an UL easy. This is an upside and would be nice if more countries would follow.

Yes it probably would, but of course they don't. Just ask Jonkers how good strategy is to design and build a glider, and then wait authorities to change their regulations to certify it. They waited what 7-8 years before caving in with JS1. As most of us know, Slovakia has a huge UL industry and their regulations are probably made to fit that "nicely", ie. someone just puts stamps on papers and don't bother with anything. Good for slovakians.

Eric Greenwell[_4_]

August 19th 20, 02:21 PM

2G wrote on 8/18/2020 10:10 PM:
> On Tuesday, August 18, 2020 at 7:26:51 PM UTC-7, Eric Greenwell wrote:
>> 2G wrote on 8/18/2020 3:07 PM:
>>> On Tuesday, August 18, 2020 at 1:49:35 PM UTC-7, andy l wrote:

>>> GP doesn't just claim "lower weight," but "far lower weight" than other gliders, but w/o any evidence to support this claim. The only real evidence I have seen is that Sebastian Kawa was very unhappy with the glider GP delivered to him and switched gliders at the last minute. Kawa also had a propulsion failure while flying a GP-14 in Italy, yet GP gliders makes this bizarre claim on their website:
>>>
>>> "The motor can be deployed and running at full power within five seconds providing confidence in the event of when a â€˜low saveâ€™ is on the cards."
>>>
>>> I guess Sebastian didn't get the memo on how reliable GP propulsion systems are. You are certainly welcome to accept all of GP's claims w/o any evidence, but I won't. And I certainly wouldn't send them six figures in cash for it.
>> The motor can indeed be deployed and running in 5 seconds, and with considerable
>> confidence. The original mechanical mast switch, external to the mast, was deemed
>> too vulnerable to damage after Kawa's accident with the prototype glider. It was
>> replaced with two redundant, buried solid state switches to prevent a repeat of
>> the problem. You've had a similar switch failure on your Schleicher glider, but
>> were lucky that it eventually worked after repeated attempts. Other Schleicher
>> owners have also experienced mast switch failures, but Schleicher still uses the
>> external mechanical switches. Maybe they didn't get the memo?
>> --
>> Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
>> - "A Guide to Self-Launching Sailplane Operation"
>> https://sites.google.com/site/motorgliders/publications/download-the-guide-1
>
> I DIDN'T have a similar failure - in fact, I had no failure at all. The switch was in perfect working order, the only explanation was flying a little too fast for the mast to deploy fully. In any event, this has NOTHING to do with the outrageous claims being made by GP Gliders. No one should depend upon propulsion to start in an emergency.

My main point was we shouldn't judge a product on a failure in a prototype a
couple years ago, as there have been many changes made since then.

My apologies - I did not realize you'd concluded it was pilot error that caused
your problem; even so, other pilots have had failed switches, including myself.
For the particular failure I had, Schleicher did respond by switching to more
water resistant switches.

This is off topic, but since I fly a Schleicher glider with the same engine
system, how fast were you flying when the problem occurred?

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications/download-the-guide-1

Eric Greenwell[_4_]

August 19th 20, 02:29 PM

jld wrote on 8/19/2020 3:01 AM:
> Certification requirements have forced manufacturers to significantly increase the weight of their gliders (e.g. cockpit protection). Because more recent airfoils are tolerant to higher WL, this has not been a significant issue, except for the fact MTM goes up and self launchers need more power!
> By using experimental in US and UL in EU, GP has more design freedom. For example, not proposing a heavy 16G cockpit but a rescue parachute instead!

Do you know how much the "16G cockpit" adds in weight, compared to the cockpit
requirement of a glider with a rescue parachute? Or asking another way: is a
glider designed to the "16G cockpit" standard heavier than one designed with a
rescue parachute (and including the parachute weight)?

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications/download-the-guide-1

andy l

August 19th 20, 03:16 PM

On Wednesday, 19 August 2020 at 11:02:00 UTC+1, jld wrote:
> ""GP doesn't just claim "lower weight," but "far lower weight" than other gliders, but w/o any evidence to support this claim""
> The evidences are in the design and certification choices.
>
> GP15 is about same empty weight as the H301 which was a fiberglass ship, so there is nothing new. Carbon now allows to use lower relative thickness airfoil and higher aspect ratio wings to get to higher performance.
>
> Certification requirements have forced manufacturers to significantly increase the weight of their gliders (e.g. cockpit protection). Because more recent airfoils are tolerant to higher WL, this has not been a significant issue, except for the fact MTM goes up and self launchers need more power!
> By using experimental in US and UL in EU, GP has more design freedom. For example, not proposing a heavy 16G cockpit but a rescue parachute instead!

You suggested this company has better materials and design techniques than its rivals. It's somewhat fatuous to then introduce a 55+ year old design into the discussion.

If you were giving us this somewhat patronising explanation in 1980, you might have a point. Schempp-Hirth were able to use knowledge gained from prototype wind turbine blades to build an all carbon wing for the Mini Nimbus. I said to the agent in our country why don't they produce a new design with thinner and higher aspect ratio wings. I'm sure they had the idea themselves without any help from me

Certification standards aren't just random paperwork for the fun of it

You laud the idea of reducing cockpit strength. Oh great. I've seen the floppy cockpit sides on another recent lightweight glider. A friend held both side rails and moved them an inch or two in and out; he might have been able to snap or peel something apart with a bit more effort. Another glider type a few years ago achieved the distinction of being banned from operating at one club, and I can't say I'm surprised, given what a different friend found

Another place to try to save weight is on control surfaces. There's geared extra payback from reducing mass balances. For the rudder this can get extra gearing again for the minimum cockpit weight. Is mass balancing going to be an area where this glider will save weight? How fast will it go?

Another post above mentions wings drooping fore and aft of the spar due to insufficient curing. I hadn't heard that before, but sorry, if true this just sounds amateurish. The rivals post cure in the moulds overnight, carefully controlled and logged temperature and time. Some parts of the process don't have shortcuts.

..

krasw

August 19th 20, 03:21 PM

On Wednesday, 19 August 2020 at 16:29:13 UTC+3, Eric Greenwell wrote:
> jld wrote on 8/19/2020 3:01 AM:
> Do you know how much the "16G cockpit" adds in weight, compared to the cockpit
> requirement of a glider with a rescue parachute? Or asking another way: is a
> glider designed to the "16G cockpit" standard heavier than one designed with a
> rescue parachute (and including the parachute weight)?
> --
> Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
> - "A Guide to Self-Launching Sailplane Operation"
> https://sites.google.com/site/motorgliders/publications/download-the-guide-1

I asked few years ago german glider producer CEO (you quess) about future of std. class. He said that they could design and build better std. class ship than previous generation (they all are from late 90s), but performance gain would be offset by requirement to build stronger fuselage than previous gen. glider that would weigh a lot more.

jld

August 19th 20, 03:47 PM

"No they don't. You have a 470kg glider in UL class that has MTOM of 472,5 kg (if national regs allow). Now EASA says that you can design and build an UL aircraft that has MTOM of 600kg (if national regs allow). The 470 kg GP fits into that weight limit perfectly"

Maybe I was not clear enough and we fail to communicate.
With new EASA limit (i.e. 600kg) the national limitS are being updated.
If you check updated UL national regulations you will discover that there is more than MTOM being updated and influencing your design (Empty weight, minimum Payload, Vso, etc.).
Controlling the empty weight is certainly on the critical path to meet a lot of the requirements.

jld

August 19th 20, 04:14 PM

"is a glider designed to the "16G cockpit" standard heavier than one designed with a rescue parachute (and including the parachute weight)?"

A designer would give you a precise answer but if you consider that you trade your back parachute against a rescue system, the delta is probably no more than 3kg (11kg - 8kg).
This is likely much less than the additional weight required by latest EASA regs on cockpit integrity.
The problem is that if you certify under EASA, you don't have the choice to go one way or the other. Therefore if you want the rescue system, weight goes up.

jld

August 19th 20, 04:27 PM

"You suggested this company has better materials and design techniques than its rivals"
You should rad post more carefully, I don't recall having suggested GP has better materials. My only point was that the weight they are claiming aren't so incredible.

I will not challenge your other statements since you seem be astute in aircraft design, certification and manufacturing.

krasw

August 19th 20, 05:24 PM

On Wednesday, 19 August 2020 at 17:47:52 UTC+3, jld wrote:
> "No they don't. You have a 470kg glider in UL class that has MTOM of 472,5 kg (if national regs allow). Now EASA says that you can design and build an UL aircraft that has MTOM of 600kg (if national regs allow). The 470 kg GP fits into that weight limit perfectly"
> Maybe I was not clear enough and we fail to communicate.
> With new EASA limit (i.e. 600kg) the national limitS are being updated.
> If you check updated UL national regulations you will discover that there is more than MTOM being updated and influencing your design (Empty weight, minimum Payload, Vso, etc.).

I checked and can confirm that you are wrong. There are no such regulations, other than allowed MTOM being higher (for sailplanes). For airplanes, only new rule is 45 kts stall speed instead of old 35 kts. I suspect your motivation for telling lies post after post is that you are GP dealer?

I find it quite amazing that GP has been selling (though obviously not producing) GP15s for years and now they state that they "freeze the design" by Q1 2021. I mean what the actual f*ck? They are still designing it!? I saw prototype flying in 2018. Well good luck for those who have paid in advance.

Dan Marotta

August 19th 20, 05:48 PM

Remember your high school chemistry (or was it physics?).Â* Water gives
up 1 calorie per gram per degree C while cooling.Â* To transition from
water at zero deg C to ice at zero deg C requires the loss of 80
calories per gram per degree C.Â* That's a lot of heat to be lost!Â* Sure,
you have a large surface area, but you have a very large volume as
well.Â* It would take quite some time to freeze a ballast tank.

Bottom line is I never worried about icing the ballast tanks (when I had
them) at sub-freezing temperatures.Â* Now freezing the dump valves is a
different issue, but not really if you fly your glider all the way to a
stop.Â* I once landed my LAK-17a with nearly 50 gallons on board and
didn't notice until after getting out of the glider.Â* Another time, one
dump valve stuck closed and, again, I landed with 25 gallons in one wing
and empty in the other.Â* I didn't notice until coming to a stop and the
full wing dropped heavily.

On 8/18/2020 8:06 PM, Eric Greenwell wrote:
> wrote on 8/18/2020 3:54 PM:
>> On Tuesday, August 18, 2020 at 10:39:00 AM UTC-7, Eric Greenwell wrote:
>>> jld wrote on 8/18/2020 9:57 AM:
>>>> Â*Â* "Glider pilots on the Allegheny Ridges (ridge soaring), in
>>>> Western US high deserts (thermal soaring), and in the Sierra wave
>>>> sometimes use higher wing loading"
>>>>
>>>> Then the GP15 might be able to satisfy these US pilots as long as
>>>> they use antifreeze in the ballast :-).
>>>> Also you might not be able to get all the benefits of high WL if
>>>> you are limited by Vne due to high altitude.
>>>>
>>>> I have been lucky to fly in Minden before.
>>>> Unless you compete in the WGC or are trying to beat a world record,
>>>> 60 kg/m2 would already be A lot.
>>>>
>>>> Bottom line, lets look for news from GP or the dealers to get
>>>> confirmation of configuration and delivery dates...
>>>
>>> No antifreeze needed in the summer, as the temperatures at 18,000'
>>> are not cold
>>> enough to freeze the water in the wings. Winter wave flying is much
>>> colder, of
>>> course, and wave runners that get permission to fly above 18,000'
>>> have to consider
>>> the temperature at any time of the year.
>>>
>>> According to the recent provisional manual, the GP15 VNE is 162 kts
>>> IAS up to 3000
>>> meters; 143 kts IAS at 6000 meters. That's about 195 kts TAS from
>>> 3000 meter on
>>> up, so a pretty high limit, especially compared to my ASH26E, with
>>> it's 143 kt
>>> VNE. I don't know what modern gliders have for VNE, or wing loading,
>>> for that matter.
>>>
>
>>
>> Eric, what air temp do you regard as cold enough to freeze water in
>> the wings?
>
> The situation I mentioned - summer in high desert areas - means ground
> elevations of 5000' or more, and with ground temperatures of 90+, it
> will be 25 deg F at 18,000. With the ups and downs of thermal flying,
> the average temperature will be around freezing, so the water ballast
> won't be cold enough long enough to freeze.
>
> For other situations, I really don't know. In thermal conditions, I
> wouldn't worry unless the minimum temperature went below 20 deg F.
> Perhaps a temperature meter with a remote probe in the wing tank is
> the safest thing. The glider handbook may have guidance, too. A
> wireless sensor might be easiest to use for the wing
>
>

--
Dan, 5J

andy l

August 19th 20, 06:52 PM

On Wednesday, 19 August 2020 at 16:27:43 UTC+1, jld wrote:
> "You suggested this company has better materials and design techniques than its rivals"
> You should rad post more carefully, I don't recall having suggested GP has better materials. My only point was that the weight they are claiming aren't so incredible.
>
> I will not challenge your other statements since you seem be astute in aircraft design, certification and manufacturing.

No need for the sarcasm.

I'm not any better informed than average, and I'm not pretending to be

You however have been smearing companies who have been making thousands of gliders for decades, airworthiness authorities in several countries, and more besides, and your expertise, whatever it is, propounds the low weight benefits of weaker cockpits (a claim not made by the manufacturer) and the cleverness or convenience of bypassing other standards

Yes, certification does cost money, so finding another category with less of it can be an advantage, but you may cause concern if it sounds like you suggest glossing over design work too.

Dave Nadler

August 19th 20, 07:45 PM

On Tuesday, August 18, 2020 at 10:26:51 PM UTC-4, Eric Greenwell wrote:
> ... The original mechanical mast switch, external to the mast, was deemed
> too vulnerable to damage after Kawa's accident with the prototype glider.
> It was replaced with two redundant, buried solid state switches
> to prevent a repeat of the problem.

Um, you might want to review my discussion of limit switch problems here:
https://www.youtube.com/watch?v=R--m0NDR0j8&t=6s

jld

August 19th 20, 07:49 PM

"I checked and can confirm that you are wrong"
Before telling people they are wrong, you should "check" a little bit more.
The information is not always easy to access from "Google" and you need too look for national authorities or UL organizations to get he data.
Just to use an example I already provided, France limits single seat class 3 UL to 238kg empty weight, with a 21 kg fuel lump weight and 86kg pilot lump weight. This gets to the 345 kg MOTM. They also limit Vso to 70 km/h at MTOM.
In the case of electric propulsion, DGAC (French authority) allows to transfer the 21kg of fuel lump weight into the empty weight. Therefore maximum empty weight of single seat electric powered class 3 UL with batteries is 259kg. As you can see, this is quite different from the 600kg 45 Kts you refer to.

"I suspect your motivation for telling lies post after post is that you are GP dealer?"
I am certainly intrigued and interested by the GP15 and I have done some reverse engineering to try better understand it but, I am not a GP dealer.
I don't pretend to be always correct but I feel offended when you state I am lying. I don't mind to stand corrected if you can point to specific points which you believe are not correct.

jld

August 19th 20, 09:35 PM

Indeed sarcasm is not useful and it was just a useless response to your statements.

I don't believe I have been smearing at anybody.
I certainly complained about poor communication from established glider manufacturers. Being lucky to be an owner, I certainly have experience in this domain.

I don't propound weaker cockpits, if you read carefully, I am suggesting there might be a better safety trade to invest weight in a new rescue system instead of a new 16G cockpit. You don't have this choice under CS but you have it under UL. Of course if you can get both, without significant weight and CG effect and, at an affordable price, it would be the cherry on the cake!

Cert authorities have introduced regulation changes with the right intention in mind but, sometimes not appreciating the value/risk benefit. To use the previous example, if it was possible, from an overall safety standpoint I would rather fly a glider with a cockpit designed under previous cockpit structural requirements (e.g. Ventus 2, DG800, etc.) equipped with a rescue system, instead of a brand new V3 or JS3 designed per the new standards, without a rescue system.

If you are concerned about UL design in EU, you should look at the DULV (Germany) requirements. This is very comprehensive. Because Germany is a large market, UL manufacturers in EU make sure their design can pass the validation tests which can then be reused for other nations validation.

[email protected]

August 19th 20, 10:05 PM

On Wednesday, August 19, 2020 at 9:49:11 AM UTC-7, Dan Marotta wrote:
> Remember your high school chemistry (or was it physics?).Â* Water gives
> up 1 calorie per gram per degree C while cooling.Â* To transition from
> water at zero deg C to ice at zero deg C requires the loss of 80
> calories per gram per degree C.Â* That's a lot of heat to be lost!Â* Sure,
> you have a large surface area, but you have a very large volume as
> well.Â* It would take quite some time to freeze a ballast tank.
>
> Bottom line is I never worried about icing the ballast tanks (when I had
> them) at sub-freezing temperatures.Â* Now freezing the dump valves is a
> different issue, but not really if you fly your glider all the way to a
> stop.Â* I once landed my LAK-17a with nearly 50 gallons on board and
> didn't notice until after getting out of the glider.Â* Another time, one
> dump valve stuck closed and, again, I landed with 25 gallons in one wing
> and empty in the other.Â* I didn't notice until coming to a stop and the
> full wing dropped heavily.
>
> On 8/18/2020 8:06 PM, Eric Greenwell wrote:
> > wrote on 8/18/2020 3:54 PM:
> >> On Tuesday, August 18, 2020 at 10:39:00 AM UTC-7, Eric Greenwell wrote:
> >>> jld wrote on 8/18/2020 9:57 AM:
> >>>> Â*Â* "Glider pilots on the Allegheny Ridges (ridge soaring), in
> >>>> Western US high deserts (thermal soaring), and in the Sierra wave
> >>>> sometimes use higher wing loading"
> >>>>
> >>>> Then the GP15 might be able to satisfy these US pilots as long as
> >>>> they use antifreeze in the ballast :-).
> >>>> Also you might not be able to get all the benefits of high WL if
> >>>> you are limited by Vne due to high altitude.
> >>>>
> >>>> I have been lucky to fly in Minden before.
> >>>> Unless you compete in the WGC or are trying to beat a world record,
> >>>> 60 kg/m2 would already be A lot.
> >>>>
> >>>> Bottom line, lets look for news from GP or the dealers to get
> >>>> confirmation of configuration and delivery dates...
> >>>
> >>> No antifreeze needed in the summer, as the temperatures at 18,000'
> >>> are not cold
> >>> enough to freeze the water in the wings. Winter wave flying is much
> >>> colder, of
> >>> course, and wave runners that get permission to fly above 18,000'
> >>> have to consider
> >>> the temperature at any time of the year.
> >>>
> >>> According to the recent provisional manual, the GP15 VNE is 162 kts
> >>> IAS up to 3000
> >>> meters; 143 kts IAS at 6000 meters. That's about 195 kts TAS from
> >>> 3000 meter on
> >>> up, so a pretty high limit, especially compared to my ASH26E, with
> >>> it's 143 kt
> >>> VNE. I don't know what modern gliders have for VNE, or wing loading,
> >>> for that matter.
> >>>
> >
> >>
> >> Eric, what air temp do you regard as cold enough to freeze water in
> >> the wings?
> >
> > The situation I mentioned - summer in high desert areas - means ground
> > elevations of 5000' or more, and with ground temperatures of 90+, it
> > will be 25 deg F at 18,000. With the ups and downs of thermal flying,
> > the average temperature will be around freezing, so the water ballast
> > won't be cold enough long enough to freeze.
> >
> > For other situations, I really don't know. In thermal conditions, I
> > wouldn't worry unless the minimum temperature went below 20 deg F.
> > Perhaps a temperature meter with a remote probe in the wing tank is
> > the safest thing. The glider handbook may have guidance, too. A
> > wireless sensor might be easiest to use for the wing
> >
> >
>
> --
> Dan, 5J

Water expands as it forms ice, so the pressure may rise enormously in trapped volumes (as in burst water pipes). Are there ballast vents apart from the valves, and do they freeze closed too? I'm waving my hands, maybe there is no worry, but personally I dump all water at 2C, as SH recommends.

Dan Marotta

August 19th 20, 11:31 PM

You are correct about water expanding as it freezes.Â* It also contracts
to its smallest volume at 4 deg C, IIRC.Â* My point was that it takes a
long time for that mass to freeze.Â* I had not considered the tank vents
and, given their small relative diameter, I would expect them to freeze
well before the tanks if they have water inside them.

It is certainly not a bad idea to dump water as the manufacturer recommends.

On 8/19/2020 3:05 PM, wrote:
> On Wednesday, August 19, 2020 at 9:49:11 AM UTC-7, Dan Marotta wrote:
>> Remember your high school chemistry (or was it physics?).Â* Water gives
>> up 1 calorie per gram per degree C while cooling.Â* To transition from
>> water at zero deg C to ice at zero deg C requires the loss of 80
>> calories per gram per degree C.Â* That's a lot of heat to be lost!Â* Sure,
>> you have a large surface area, but you have a very large volume as
>> well.Â* It would take quite some time to freeze a ballast tank.
>>
>> Bottom line is I never worried about icing the ballast tanks (when I had
>> them) at sub-freezing temperatures.Â* Now freezing the dump valves is a
>> different issue, but not really if you fly your glider all the way to a
>> stop.Â* I once landed my LAK-17a with nearly 50 gallons on board and
>> didn't notice until after getting out of the glider.Â* Another time, one
>> dump valve stuck closed and, again, I landed with 25 gallons in one wing
>> and empty in the other.Â* I didn't notice until coming to a stop and the
>> full wing dropped heavily.
>>
>> On 8/18/2020 8:06 PM, Eric Greenwell wrote:
>>> wrote on 8/18/2020 3:54 PM:
>>>> On Tuesday, August 18, 2020 at 10:39:00 AM UTC-7, Eric Greenwell wrote:
>>>>> jld wrote on 8/18/2020 9:57 AM:
>>>>>> Â*Â* "Glider pilots on the Allegheny Ridges (ridge soaring), in
>>>>>> Western US high deserts (thermal soaring), and in the Sierra wave
>>>>>> sometimes use higher wing loading"
>>>>>>
>>>>>> Then the GP15 might be able to satisfy these US pilots as long as
>>>>>> they use antifreeze in the ballast :-).
>>>>>> Also you might not be able to get all the benefits of high WL if
>>>>>> you are limited by Vne due to high altitude.
>>>>>>
>>>>>> I have been lucky to fly in Minden before.
>>>>>> Unless you compete in the WGC or are trying to beat a world record,
>>>>>> 60 kg/m2 would already be A lot.
>>>>>>
>>>>>> Bottom line, lets look for news from GP or the dealers to get
>>>>>> confirmation of configuration and delivery dates...
>>>>> No antifreeze needed in the summer, as the temperatures at 18,000'
>>>>> are not cold
>>>>> enough to freeze the water in the wings. Winter wave flying is much
>>>>> colder, of
>>>>> course, and wave runners that get permission to fly above 18,000'
>>>>> have to consider
>>>>> the temperature at any time of the year.
>>>>>
>>>>> According to the recent provisional manual, the GP15 VNE is 162 kts
>>>>> IAS up to 3000
>>>>> meters; 143 kts IAS at 6000 meters. That's about 195 kts TAS from
>>>>> 3000 meter on
>>>>> up, so a pretty high limit, especially compared to my ASH26E, with
>>>>> it's 143 kt
>>>>> VNE. I don't know what modern gliders have for VNE, or wing loading,
>>>>> for that matter.
>>>>>
>>>> Eric, what air temp do you regard as cold enough to freeze water in
>>>> the wings?
>>> The situation I mentioned - summer in high desert areas - means ground
>>> elevations of 5000' or more, and with ground temperatures of 90+, it
>>> will be 25 deg F at 18,000. With the ups and downs of thermal flying,
>>> the average temperature will be around freezing, so the water ballast
>>> won't be cold enough long enough to freeze.
>>>
>>> For other situations, I really don't know. In thermal conditions, I
>>> wouldn't worry unless the minimum temperature went below 20 deg F.
>>> Perhaps a temperature meter with a remote probe in the wing tank is
>>> the safest thing. The glider handbook may have guidance, too. A
>>> wireless sensor might be easiest to use for the wing
>>>
>>>
>> --
>> Dan, 5J
> Water expands as it forms ice, so the pressure may rise enormously in trapped volumes (as in burst water pipes). Are there ballast vents apart from the valves, and do they freeze closed too? I'm waving my hands, maybe there is no worry, but personally I dump all water at 2C, as SH recommends.

--
Dan, 5J

August 20th 20, 01:14 AM

On Wednesday, August 19, 2020 at 3:02:00 AM UTC-7, jld wrote:
> ""GP doesn't just claim "lower weight," but "far lower weight" than other gliders, but w/o any evidence to support this claim""
> The evidences are in the design and certification choices.
>
> GP15 is about same empty weight as the H301 which was a fiberglass ship, so there is nothing new. Carbon now allows to use lower relative thickness airfoil and higher aspect ratio wings to get to higher performance.
>
> Certification requirements have forced manufacturers to significantly increase the weight of their gliders (e.g. cockpit protection). Because more recent airfoils are tolerant to higher WL, this has not been a significant issue, except for the fact MTM goes up and self launchers need more power!
> By using experimental in US and UL in EU, GP has more design freedom. For example, not proposing a heavy 16G cockpit but a rescue parachute instead!

That is more closely akin to wishful thinking than evidence. Since GP isn't going to certify their gliders to EASA standards we do not know anything about their testing process. A ballistic chute is not going to help you unless you deploy it, which you can't do in the landing phase, the most likely time you will need a strengthened cockpit. My idea of evidence is things like the ultimate breaking strength of a wing taken to destruction (which you must do for EASA certification). Ultralights may be exempted from this testing by each member country so we will not even know if GP has done this test unless they produce the test results from an independent testing company.. I am just not willing to take such things on faith if my life depends upon it (which it does).

Tom

August 20th 20, 01:46 AM

On Wednesday, August 19, 2020 at 6:21:50 AM UTC-7, Eric Greenwell wrote:
> 2G wrote on 8/18/2020 10:10 PM:
> > On Tuesday, August 18, 2020 at 7:26:51 PM UTC-7, Eric Greenwell wrote:
> >> 2G wrote on 8/18/2020 3:07 PM:
> >>> On Tuesday, August 18, 2020 at 1:49:35 PM UTC-7, andy l wrote:
>
> >>> GP doesn't just claim "lower weight," but "far lower weight" than other gliders, but w/o any evidence to support this claim. The only real evidence I have seen is that Sebastian Kawa was very unhappy with the glider GP delivered to him and switched gliders at the last minute. Kawa also had a propulsion failure while flying a GP-14 in Italy, yet GP gliders makes this bizarre claim on their website:
> >>>
> >>> "The motor can be deployed and running at full power within five seconds providing confidence in the event of when a â€˜low saveâ€™ is on the cards."
> >>>
> >>> I guess Sebastian didn't get the memo on how reliable GP propulsion systems are. You are certainly welcome to accept all of GP's claims w/o any evidence, but I won't. And I certainly wouldn't send them six figures in cash for it.
> >> The motor can indeed be deployed and running in 5 seconds, and with considerable
> >> confidence. The original mechanical mast switch, external to the mast, was deemed
> >> too vulnerable to damage after Kawa's accident with the prototype glider. It was
> >> replaced with two redundant, buried solid state switches to prevent a repeat of
> >> the problem. You've had a similar switch failure on your Schleicher glider, but
> >> were lucky that it eventually worked after repeated attempts. Other Schleicher
> >> owners have also experienced mast switch failures, but Schleicher still uses the
> >> external mechanical switches. Maybe they didn't get the memo?
> >> --
> >> Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
> >> - "A Guide to Self-Launching Sailplane Operation"
> >> https://sites.google.com/site/motorgliders/publications/download-the-guide-1
> >
> > I DIDN'T have a similar failure - in fact, I had no failure at all. The switch was in perfect working order, the only explanation was flying a little too fast for the mast to deploy fully. In any event, this has NOTHING to do with the outrageous claims being made by GP Gliders. No one should depend upon propulsion to start in an emergency.
> My main point was we shouldn't judge a product on a failure in a prototype a
> couple years ago, as there have been many changes made since then.
>
> My apologies - I did not realize you'd concluded it was pilot error that caused
> your problem; even so, other pilots have had failed switches, including myself.
> For the particular failure I had, Schleicher did respond by switching to more
> water resistant switches.
>
> This is off topic, but since I fly a Schleicher glider with the same engine
> system, how fast were you flying when the problem occurred?
> --
> Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
> - "A Guide to Self-Launching Sailplane Operation"
> https://sites.google.com/site/motorgliders/publications/download-the-guide-1

I assume that I was flying too fast because no mechanical anomalies were found, including subsequent deployment tests on that same flight. My recollection was around 60kt (it certainly wasn't 70 or more). Looking at the flight track (https://www.onlinecontest.org/olc-3.0/gliding/flightinfo.html?dsId=4554327) I estimate that my IAS was around 60kt, which shouldn't have been too fast (there was an apparent tailwind of around 14kt that has to be subtracted from the ground speed). The ASH26e flight manual lists the max prop extend speed as 65kt. It would be a good test to find out what speed is too fast. But it is a single point of failure that can prevent the operation of the engine.

Tom

Bob Gibbons[_2_]

August 20th 20, 02:22 AM

On Wed, 19 Aug 2020 10:48:30 -0600, Dan Marotta
> wrote:

>Remember your high school chemistry (or was it physics?).* Water gives
>up 1 calorie per gram per degree C while cooling.* To transition from
>water at zero deg C to ice at zero deg C requires the loss of 80
>calories per gram per degree C.* That's a lot of heat to be lost!* Sure,
>you have a large surface area, but you have a very large volume as
>well.* It would take quite some time to freeze a ballast tank.
>
>Bottom line is I never worried about icing the ballast tanks (when I had
>them) at sub-freezing temperatures.* Now freezing the dump valves is a
>different issue, but not really if you fly your glider all the way to a
>stop.* I once landed my LAK-17a with nearly 50 gallons on board and
>didn't notice until after getting out of the glider.* Another time, one
>dump valve stuck closed and, again, I landed with 25 gallons in one wing
>and empty in the other.* I didn't notice until coming to a stop and the
>full wing dropped heavily.
>
.... text deleted

Maybe off topic, but what worried me in past years when I flew in the
New Mexico mountains was not the wing ballast tanks, but the tail
tank.

I always had visions of the tail tank freezing and failing to dump
when I dropped ballast, leaving my CG too far aft.

I usually left the tail tank empty if I was expecting high altitutes.

Bob

[email protected]

August 20th 20, 04:03 AM

I fly NM with water regularly, both in the wings and the tail. I generally fly dry in the early spring when temperatures are still sub freezing at 17,000+ and start filling up during the summer. No problems so far, but if I do decide to use water in the tail tank when it's really cold, I can always add some propylene glycol antifreeze. Several of our more manic pilots do that and it seems to work well.

jld

August 20th 20, 06:12 AM

"My idea of evidence is things like the ultimate breaking strength of a wing taken to destruction (which you must do for EASA certification)"

It is up to GP to negotiate with DULV (Germany), but ultimate load test will have to be performed and DULV will probably ask to go to rupture since it is a brand new design. DULV also has to witness this type tests.
I was skeptical about UL for a long time until I took the time to dig into the different national regulations and realize most countries had very high standards.
if you can read German, here is a link to LTF-UL which defines requirements for approval.
https://www.dulv.de/sites/default/files/Downloads/Ausbildungshandbuch%20DULV%201.22_0.pdf
There is an older version in English available from the net: https://drive.google.com/file/d/0BzPJgl_0QQ4oa21NMURlVUlCQjA/view?usp=sharing

kinsell

August 20th 20, 02:11 PM

Digging through some old FaceBook postings, looks like Jeta SN 0001 was
issued a CoA from the Slovak Federation of Ultralights on May 30 2018
with a MTOM of 525 KG.

They got that weight by claiming it was 51% homebuilt. Wow.

Eric Greenwell[_4_]

August 20th 20, 07:50 PM

kinsell wrote on 8/20/2020 6:11 AM:
> Digging through some old FaceBook postings, looks like Jeta SN 0001 was issued a
> CoA from the Slovak Federation of Ultralights on May 30 2018 with a MTOM of 525 KG.
>
> They got that weight by claiming it was 51% homebuilt.** Wow.

Was the word used really "homebuilt"? Regardless, they built the glider, they
aren't going to sell it, they plan to destroy it for strength testing, and are
expecting the regulations to allow 525 kg in a year or two - I don't see the "wow"
in that claim. And maybe that's SOP for the Slovak authorities; after all, here in
the US we routinely get CoAs in the "Experimental" category for certified gliders.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications/download-the-guide-1

kinsell

August 21st 20, 01:33 AM

On 8/20/20 12:50 PM, Eric Greenwell wrote:
> kinsell wrote on 8/20/2020 6:11 AM:
>> Digging through some old FaceBook postings, looks like Jeta SN 0001
>> was issued a CoA from the Slovak Federation of Ultralights on May 30
>> 2018 with a MTOM of 525 KG.
>>
>> They got that weight by claiming it was 51% homebuilt.Â*Â* Wow.
>
> Was the word used really "homebuilt"? Regardless, they built the glider,
> they aren't going to sell it, they plan to destroy it for strength
> testing, and are expecting the regulations to allow 525 kg in a year or
> two - I don't see the "wow" in that claim. And maybe that's SOP for the
> Slovak authorities; after all, here in the US we routinely get CoAs in
> the "Experimental" category for certified gliders.
>

Yes, someone from Belgium asked how they got 525 kg. "Did you apply for
a 51% homebuilt certification?" GP replied "Basically yes".

This is the same glider they put together in a hurry for Sebastian, and
was later used for customer demo flights. I think a legitimate CoA
would have been appropriate. Perhaps that is just how the Slovakian
authorities do business. I think it's clear GP went shopping for a
rather lenient agency to deal with.

August 21st 20, 05:19 AM

On Wednesday, August 19, 2020 at 10:12:43 PM UTC-7, jld wrote:
> "My idea of evidence is things like the ultimate breaking strength of a wing taken to destruction (which you must do for EASA certification)"
> It is up to GP to negotiate with DULV (Germany), but ultimate load test will have to be performed and DULV will probably ask to go to rupture since it is a brand new design. DULV also has to witness this type tests.
> I was skeptical about UL for a long time until I took the time to dig into the different national regulations and realize most countries had very high standards.
> if you can read German, here is a link to LTF-UL which defines requirements for approval.
> https://www.dulv.de/sites/default/files/Downloads/Ausbildungshandbuch%20DULV%201.22_0.pdf
> There is an older version in English available from the net: https://drive.google.com/file/d/0BzPJgl_0QQ4oa21NMURlVUlCQjA/view?usp=sharing

That is just an organization and training manual.

jld

August 21st 20, 06:19 AM

second link is OK but first link should point to : http://www.dulv.de/sites/default/files/Downloads/LTF_aerodynamische_UL%20NfL_II_446_19_1.pdf

jld

August 21st 20, 08:24 AM

"regulations to allow 525 kg in a year or two"
Maybe some countries could increase MTOM (up to 600 kg) but don't forget that the glider must still demonstrate a certain Vso at that MTOM.
Given the small surface of the GP15 (7,78 m2), the low relative thickness of the airfoil (required to get to high L/D), it is going to already be excellent if they can meet the 45 Kts Vso limit at 470 Kg (which is 60 kg/m2).
If you register outside EU and the 45 Kts Vso limit does not apply, going to higher WL/Vso means climbing at IAS above 60 kts.

You can always increase WL to improve your task speed but this is not going to help much if you start from a bad polar curve.
If they can get close to their polar and achieve 2 m/s sink rate at 200 km/h with 45 kg/m2 WL, then GP15 will be an excellent cruiser.

krasw

August 21st 20, 12:36 PM

One would think that glider structure would be the most important factor when setting the MTOM, but we clearly are not talking about certified glider and it doesn't matter.

Eric Greenwell[_4_]

August 21st 20, 03:49 PM

krasw wrote on 8/21/2020 4:36 AM:
> One would think that glider structure would be the most important factor when setting the MTOM, but we clearly are not talking about certified glider and it doesn't matter.
>
I think it is the other way around: the designer chooses a MTOM based on many
interacting factors, such as required minimum stall speed, the aspect ratio and
airfoil needed to achieve the desired soaring performance (including the range of
wing loadings). Once a MTOM is selected, the structure is designed to support it;
of course, it is an iterative procedure, as the structure weight may then
require/allow a change in the other factors, or even selecting a different MTOM.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications/download-the-guide-1

jld

August 21st 20, 04:09 PM

"One would think that glider structure would be the most important factor when setting the MTOM"
I did not look at CS22 and LTF-UL side by side but for the validation methodology they seem to be very close.
In both regulations structure is designed to be capable of limit/ultimate loads at MTOM.
And in both regulations you need to demonstrate Vso at MTOM.
Therefore if you run out of lift coefficient with flaps setting (which has nothing to do with structure strength), you might have structural margin but be forced to reduce MTOM.
If GP can demonstrate 45Kts Vso at 470kg and demonstrate the structure is capable of 5,3g at 470kg, this will be excellent and no different from what CS22 would require.

jfitch

August 21st 20, 10:35 PM

On Wednesday, August 19, 2020 at 8:03:49 PM UTC-7, wrote:
> I fly NM with water regularly, both in the wings and the tail. I generally fly dry in the early spring when temperatures are still sub freezing at 17,000+ and start filling up during the summer. No problems so far, but if I do decide to use water in the tail tank when it's really cold, I can always add some propylene glycol antifreeze. Several of our more manic pilots do that and it seems to work well.
Not telling you what to do but in the Truckee/Minden area it is routine to fill the tanks and fly all day at sub freezing temps - probably 4 - 5 hours below freezing. We did have one case of the tail tank dump valve on a DuoDiscus leaking, which dribbled water onto the rudder hinge and controls, which froze the rudder in position. Pilot flew carefully home on a 200 mile final glide, descending through warmer temps and it melted enough to break loose.

August 21st 20, 11:30 PM

On Friday, August 21, 2020 at 12:24:21 AM UTC-7, jld wrote:
> "regulations to allow 525 kg in a year or two"
> Maybe some countries could increase MTOM (up to 600 kg) but don't forget that the glider must still demonstrate a certain Vso at that MTOM.
> Given the small surface of the GP15 (7,78 m2), the low relative thickness of the airfoil (required to get to high L/D), it is going to already be excellent if they can meet the 45 Kts Vso limit at 470 Kg (which is 60 kg/m2)..
> If you register outside EU and the 45 Kts Vso limit does not apply, going to higher WL/Vso means climbing at IAS above 60 kts.
>
> You can always increase WL to improve your task speed but this is not going to help much if you start from a bad polar curve.
> If they can get close to their polar and achieve 2 m/s sink rate at 200 km/h with 45 kg/m2 WL, then GP15 will be an excellent cruiser.

The $64,000 Question (yes, I am that old) is which country's certification standards, if any, is GP going to meet? They don't mention certification on their website. Also, I assume that the V-n diagram (fig. 1) are the G loads the glider must be designed for. If so, they are considerably less than what non-UL gliders must meet.

Tom

Eric Greenwell[_4_]

August 22nd 20, 05:11 AM

2G wrote on 8/21/2020 3:30 PM:
> On Friday, August 21, 2020 at 12:24:21 AM UTC-7, jld wrote:
>> "regulations to allow 525 kg in a year or two"
>> Maybe some countries could increase MTOM (up to 600 kg) but don't forget that the glider must still demonstrate a certain Vso at that MTOM.
>> Given the small surface of the GP15 (7,78 m2), the low relative thickness of the airfoil (required to get to high L/D), it is going to already be excellent if they can meet the 45 Kts Vso limit at 470 Kg (which is 60 kg/m2)..
>> If you register outside EU and the 45 Kts Vso limit does not apply, going to higher WL/Vso means climbing at IAS above 60 kts.
>>
>> You can always increase WL to improve your task speed but this is not going to help much if you start from a bad polar curve.
>> If they can get close to their polar and achieve 2 m/s sink rate at 200 km/h with 45 kg/m2 WL, then GP15 will be an excellent cruiser.
>
> The $64,000 Question (yes, I am that old) is which country's certification standards, if any, is GP going to meet? They don't mention certification on their website. Also, I assume that the V-n diagram (fig. 1) are the G loads the glider must be designed for. If so, they are considerably less than what non-UL gliders must meet.
>
> Tom
>
The G Limits for the GP15 are the same as your ASH 26 E - +5.3/-2.65.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications/download-the-guide-1

August 22nd 20, 06:28 AM

On Friday, August 21, 2020 at 9:11:39 PM UTC-7, Eric Greenwell wrote:
> 2G wrote on 8/21/2020 3:30 PM:
> > On Friday, August 21, 2020 at 12:24:21 AM UTC-7, jld wrote:
> >> "regulations to allow 525 kg in a year or two"
> >> Maybe some countries could increase MTOM (up to 600 kg) but don't forget that the glider must still demonstrate a certain Vso at that MTOM.
> >> Given the small surface of the GP15 (7,78 m2), the low relative thickness of the airfoil (required to get to high L/D), it is going to already be excellent if they can meet the 45 Kts Vso limit at 470 Kg (which is 60 kg/m2)..
> >> If you register outside EU and the 45 Kts Vso limit does not apply, going to higher WL/Vso means climbing at IAS above 60 kts.
> >>
> >> You can always increase WL to improve your task speed but this is not going to help much if you start from a bad polar curve.
> >> If they can get close to their polar and achieve 2 m/s sink rate at 200 km/h with 45 kg/m2 WL, then GP15 will be an excellent cruiser.
> >
> > The $64,000 Question (yes, I am that old) is which country's certification standards, if any, is GP going to meet? They don't mention certification on their website. Also, I assume that the V-n diagram (fig. 1) are the G loads the glider must be designed for. If so, they are considerably less than what non-UL gliders must meet.
> >
> > Tom
> >
> The G Limits for the GP15 are the same as your ASH 26 E - +5.3/-2.65.
> --
> Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
> - "A Guide to Self-Launching Sailplane Operation"
> https://sites.google.com/site/motorgliders/publications/download-the-guide-1

That is what is posted on their website, but have destructive tests been done on an actual wing by an independent lab? And, again, I ask what country's aircraft certification standards, if any, will the GP15 meet?

Tom

jld

August 22nd 20, 06:42 AM

"which country's certification standards, if any, is GP going to meet? "
If they want to sell in EU, the addressable market is large but they have no choice and need approval in Germany, France, Italy and a few other countries.
This is confirmed by the fact GP has initiated activities with DULV

As Eric mentioned, even if +4g is sufficient to satisfy UL rules, GP has elected to use the CS22 limits at 5,3g.
This being said, +4g is already good (I am that old too and can't pull that many g's in thermal anyway) and believe the gust load and Vb (see Vn diagram for gust load) are of more interest for gliders.
Because GP15 Vne is 162 kts, Vd is 180 kts and Vb=Va is 120 Kts.
This means you can fly up to 120 Kts, hit a strong rotor and be OK (the glider be OK I should say).

jld

August 22nd 20, 06:45 AM

"but have destructive tests been done on an actual wing"
They will have no choice but do it to get DULV approval.

krasw

August 22nd 20, 10:35 AM

UL "certification" does not require similar destructive test (at 54C temp) as certified gliders. It is the whole idea of UL, the manufacturers can state, without independent tests, that "we think this is ok" and buyers are aware that they are getting uncertified products.

This does not mean that manufacturer don't test their aircraft at all, of course. I bet all of them do at least simple static sandbag test to max G.

jld

August 22nd 20, 11:15 AM

"UL certification does not require similar destructive test (at 54C temp) as certified gliders"
Depends on the authorities you are dealing with.
With DULV, LTF-UL 305 (Strength and deformations) and LTF-UL 307 (Proof of strength)are pretty clear and identical to CS22.
In both cases, unless the manufacturer can justify previous experience, compliance by analysis is no possible and evidence of load tests (which must be witnessed) has to be provided.
And in both cases 54Â°C is considered normal temperature for all components.

Eric Greenwell[_4_]

August 22nd 20, 02:27 PM

2G wrote on 8/21/2020 10:28 PM:
> On Friday, August 21, 2020 at 9:11:39 PM UTC-7, Eric Greenwell wrote:
>> 2G wrote on 8/21/2020 3:30 PM:
>>> On Friday, August 21, 2020 at 12:24:21 AM UTC-7, jld wrote:
>>>> "regulations to allow 525 kg in a year or two"
>>>> Maybe some countries could increase MTOM (up to 600 kg) but don't forget that the glider must still demonstrate a certain Vso at that MTOM.
>>>> Given the small surface of the GP15 (7,78 m2), the low relative thickness of the airfoil (required to get to high L/D), it is going to already be excellent if they can meet the 45 Kts Vso limit at 470 Kg (which is 60 kg/m2)..
>>>> If you register outside EU and the 45 Kts Vso limit does not apply, going to higher WL/Vso means climbing at IAS above 60 kts.
>>>>
>>>> You can always increase WL to improve your task speed but this is not going to help much if you start from a bad polar curve.
>>>> If they can get close to their polar and achieve 2 m/s sink rate at 200 km/h with 45 kg/m2 WL, then GP15 will be an excellent cruiser.
>>>
>>> The $64,000 Question (yes, I am that old) is which country's certification standards, if any, is GP going to meet? They don't mention certification on their website. Also, I assume that the V-n diagram (fig. 1) are the G loads the glider must be designed for. If so, they are considerably less than what non-UL gliders must meet.
>>>
>>> Tom
>>>
>> The G Limits for the GP15 are the same as your ASH 26 E - +5.3/-2.65.
>
> That is what is posted on their website, but have destructive tests been done on an actual wing by an independent lab? And, again, I ask what country's aircraft certification standards, if any, will the GP15 meet?

The Velo 14 (the 13.5M version) has been tested for flutter and to destruction. A
video is on the FB page. The factory says the GP15 will be tested in Q1-2021, and
the videos will be posted afterwards.

From the Feb 2020 Provisional Flight Manual:

1.2. Certification Basis

This Motor Glider has been approved in the SFUL LSZ category -
http://www.sful.sk/smernice in accordance with the higher tier regulations of:

LTF-UL http://www.dulv.de/sites/default/files/Downloads/ltf_aerodynamische_ul.pdf

CS-22
https://www.easa.europa.eu/certification-specifications/cs-22-sailplanes-andpowered-sailplanes

Your concern for the safety of GP15 customers suggests that you might be
considering a reservation deposit to get in the order queue, just in case the GP15
works out. You would not be the first owner of a large and complicated motorglider
to do so :^)

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications/download-the-guide-1

August 24th 20, 12:59 AM

On Saturday, August 22, 2020 at 6:27:14 AM UTC-7, Eric Greenwell wrote:
> 2G wrote on 8/21/2020 10:28 PM:
> > On Friday, August 21, 2020 at 9:11:39 PM UTC-7, Eric Greenwell wrote:
> >> 2G wrote on 8/21/2020 3:30 PM:
> >>> On Friday, August 21, 2020 at 12:24:21 AM UTC-7, jld wrote:
> >>>> "regulations to allow 525 kg in a year or two"
> >>>> Maybe some countries could increase MTOM (up to 600 kg) but don't forget that the glider must still demonstrate a certain Vso at that MTOM.
> >>>> Given the small surface of the GP15 (7,78 m2), the low relative thickness of the airfoil (required to get to high L/D), it is going to already be excellent if they can meet the 45 Kts Vso limit at 470 Kg (which is 60 kg/m2)..
> >>>> If you register outside EU and the 45 Kts Vso limit does not apply, going to higher WL/Vso means climbing at IAS above 60 kts.
> >>>>
> >>>> You can always increase WL to improve your task speed but this is not going to help much if you start from a bad polar curve.
> >>>> If they can get close to their polar and achieve 2 m/s sink rate at 200 km/h with 45 kg/m2 WL, then GP15 will be an excellent cruiser.
> >>>
> >>> The $64,000 Question (yes, I am that old) is which country's certification standards, if any, is GP going to meet? They don't mention certification on their website. Also, I assume that the V-n diagram (fig. 1) are the G loads the glider must be designed for. If so, they are considerably less than what non-UL gliders must meet.
> >>>
> >>> Tom
> >>>
> >> The G Limits for the GP15 are the same as your ASH 26 E - +5.3/-2.65.
> >
> > That is what is posted on their website, but have destructive tests been done on an actual wing by an independent lab? And, again, I ask what country's aircraft certification standards, if any, will the GP15 meet?
> The Velo 14 (the 13.5M version) has been tested for flutter and to destruction. A
> video is on the FB page. The factory says the GP15 will be tested in Q1-2021, and
> the videos will be posted afterwards.
>
> From the Feb 2020 Provisional Flight Manual:
>
> 1.2. Certification Basis
>
> This Motor Glider has been approved in the SFUL LSZ category -
> http://www.sful.sk/smernice in accordance with the higher tier regulations of:
>
> LTF-UL http://www.dulv.de/sites/default/files/Downloads/ltf_aerodynamische_ul.pdf
>
> CS-22
> https://www.easa.europa.eu/certification-specifications/cs-22-sailplanes-andpowered-sailplanes
>
> Your concern for the safety of GP15 customers suggests that you might be
> considering a reservation deposit to get in the order queue, just in case the GP15
> works out. You would not be the first owner of a large and complicated motorglider
> to do so :^)
> --
> Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
> - "A Guide to Self-Launching Sailplane Operation"
> https://sites.google.com/site/motorgliders/publications/download-the-guide-1

Your CS22 link is broken.

Tom

Eric Greenwell[_4_]

August 24th 20, 03:01 AM

2G wrote on 8/23/2020 4:59 PM:
> On Saturday, August 22, 2020 at 6:27:14 AM UTC-7, Eric Greenwell wrote:
>> 2G wrote on 8/21/2020 10:28 PM:
>>> On Friday, August 21, 2020 at 9:11:39 PM UTC-7, Eric Greenwell wrote:
>>>> 2G wrote on 8/21/2020 3:30 PM:
>>>>> On Friday, August 21, 2020 at 12:24:21 AM UTC-7, jld wrote:
>>>>>> "regulations to allow 525 kg in a year or two"
>>>>>> Maybe some countries could increase MTOM (up to 600 kg) but don't forget that the glider must still demonstrate a certain Vso at that MTOM.
>>>>>> Given the small surface of the GP15 (7,78 m2), the low relative thickness of the airfoil (required to get to high L/D), it is going to already be excellent if they can meet the 45 Kts Vso limit at 470 Kg (which is 60 kg/m2)..
>>>>>> If you register outside EU and the 45 Kts Vso limit does not apply, going to higher WL/Vso means climbing at IAS above 60 kts.
>>>>>>
>>>>>> You can always increase WL to improve your task speed but this is not going to help much if you start from a bad polar curve.
>>>>>> If they can get close to their polar and achieve 2 m/s sink rate at 200 km/h with 45 kg/m2 WL, then GP15 will be an excellent cruiser.
>>>>>
>>>>> The $64,000 Question (yes, I am that old) is which country's certification standards, if any, is GP going to meet? They don't mention certification on their website. Also, I assume that the V-n diagram (fig. 1) are the G loads the glider must be designed for. If so, they are considerably less than what non-UL gliders must meet.
>>>>>
>>>>> Tom
>>>>>
>>>> The G Limits for the GP15 are the same as your ASH 26 E - +5.3/-2.65.
>>>
>>> That is what is posted on their website, but have destructive tests been done on an actual wing by an independent lab? And, again, I ask what country's aircraft certification standards, if any, will the GP15 meet?
>> The Velo 14 (the 13.5M version) has been tested for flutter and to destruction. A
>> video is on the FB page. The factory says the GP15 will be tested in Q1-2021, and
>> the videos will be posted afterwards.
>>
>> From the Feb 2020 Provisional Flight Manual:
>>
>> 1.2. Certification Basis
>>
>> This Motor Glider has been approved in the SFUL LSZ category -
>> http://www.sful.sk/smernice in accordance with the higher tier regulations of:
>>
>> LTF-UL http://www.dulv.de/sites/default/files/Downloads/ltf_aerodynamische_ul.pdf
>>
>> CS-22
>> https://www.easa.europa.eu/certification-specifications/cs-22-sailplanes-andpowered-sailplanes
>>
>> Your concern for the safety of GP15 customers suggests that you might be
>> considering a reservation deposit to get in the order queue, just in case the GP15
>> works out. You would not be the first owner of a large and complicated motorglider
>> to do so :^)
>> --

> Your CS22 link is broken.
>

A dash got lost somehow when I copied it from the pdf. This one works for me:

https://www.easa.europa.eu/certification-specifications/cs-22-sailplanes-and-powered-sailplanes
--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications/download-the-guide-1