$1 billion BMS Ooops...

On 3/18/2021 7:07 PM, waremark wrote:
When flying the Arcus M with a copilot and no ballast my wing loading is 49 kg/m2 (10 lbs/ft2). In spite of being a 'newer flapped design', in very weak lift pure gliders without ballast simply climb away from me. You may rightly assume that is indicative of my piloting skills, or lack of them!

I wasn't going to say anything...

ArcusM isn't quite as good in weak lift, but anyway it's minimum loading
is MUCH higher than the Jeta; IIRC for me and usual passengers ArcusM
was around 9.5 also. Also Ian's comparing to a non-flapped glider...

On Thursday, March 18, 2021 at 5:42:22 PM UTC-4, Eric Greenwell wrote:
India November wrote on 3/18/2021 8:50 AM:
On Wednesday, March 17, 2021 at 9:00:04 AM UTC-4, Eric Greenwell wrote:
2G wrote on 3/16/2021 10:17 PM:
On Tuesday, March 16, 2021 at 3:48:54 PM UTC-7, Eric Greenwell wrote:
2G wrote on 3/16/2021 12:46 PM:
Landing out in eastern Nevada is serious business; some may chose to fly non-motorized gliders there (which, in my mind, the GP15 is) and get away with it.
I forgot to respond to the "non-motorized" portion of your remarks. Perhaps you will be
surprised (or at least interested) to learn the GP15 climb rate from the runway on a typical
flying day at Ely will be nearly double the climb rate of my ASH26E. A major reason is the
electric motor still has the same power at 9000' DA, while the carbureted Wankel has lost about
18%. The better climb on takeoff in high density altitudes was an important factor in my
choice. It's not important at Ely, but it is at Parowan, and a few other places I've flown (or
wanted to fly but decided it was marginal).

Now, I realize you think 90 miles of self-retrieve is the same as zero miles, but that view is
not shared by every "pure" glider pilot out there!
--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1

Where do you get 90 miles? GP's website doesn't list it. Their numbers are dry - if you can trust them (nobody's verified them and they may be estimated for all you know). The self-retrieve distance they list for the B battery is 100km (63 miles) with a 800m launch with no ballast. Now add ballast, add an 3,000 ft obstacle and a 20kt headwind (all realistic conditions at Ely) and refigure what the hypothetical retrieve distance is, if any.

Take a look at this page: https://www.gpgliders.com/offer/gp-15-e-se-jeta Here's the pertinent
portion:

Usable battery capacity: 9,23 kWh
Operational battery capacity: 8,36 kWh (10% buffer to preserve battery life)
Weight: 52 kg (115 lb)

Motor glider’s self-launch and climb performance on a single charge, equipped with “B� battery
pack (TOW: 320 kg [705 lb]):

5 x take-off and climb to 800 m (2 625 ft) altitude
or 1 x take-off and climb to 800 m (2 625 ft) altitude + 150 km (93 mi) range
or 1 x take-off and total climb to 4 000 m (13 120 ft)
Max. climb rate: 4,4 m/s (8,55 kts)
Ground-roll take-off distance: 180 m (197 yards)

Because the wing area is 84 ft2, the 705lb TOW = 8.4 lb/ft2, about the same wing loading I have
in the ASH26E, unballasted.
Eric, I'm curious about the wing loadings quoted for the Jeta from 7,58-13,72 lb/ft^2. For the conditions I fly in Ontario where thermals average 2 to 4 kts, I see these heavy wing loadings as a disadvantage even in a flapped ship. I fly my D2 mostly dry at less than 6 lb/ft^2. What am I missing?
Ian IN

Are you really sure of that wing loading? The numbers on the Schmepp site suggest a wing
loading for a pilot 165lb pilot with a 15 lb parachute is over 6.5 lb/ft2.. But even it's 7
lb/ft2, it is definitely a lighter wing loading than the newer flapped 15m gliders; eg, the new
AS33-15M has a minimum wing loading of 8.5 lb/ft2, and that is without a motor.

As Dave mentions, span loading (weight/span^2) is a better indicator of thermalling ability,
and since the Discus 2A and the Jeta have the same span and about the same minimum weight
(using the weight from the Schmepp site), I'd expect them to thermal the same. It may seem
strange a lighter wing loading doesn't help more, but aspect ratio matters: the Discus has a 22
ratio, while the Jeta has 29.

And, the Jeta has a motor, so even if it did not thermal quite as well as your Discus, you'd
still have fewer landouts in it than the Discus 2. Plus, you'd love the extra speed the higher
wing loading allows during the cruise, at least 15% faster (and with a higher glide ratio, due
in part to the higher aspect ratio).
--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1

Interesting, thanks Eric. And yes, I meant 6.8ppsf min loading in my D2. What was I thinking!
Ian IN

On 3/12/21 1:38 AM, wrote:
On Friday, 12 March 2021 at 04:33:55 UTC+1, Eric Greenwell wrote:

I don't think it will take 15+ more years for electric gliders to be accepted and desired like
gas powered gliders are now. With FES and mast-mounted electrics available from all the major
manufacturers, I think this year is the "tipping point", and sales of electrics will "soon"
increase faster than the gas powered sales; unfortunately, I don't know of any good way to
track sales.

Just one datapoint, Jonker in their latest newsletter reported the following about their electrical JS3 RES:
"The first 5 JS3 RES gliders are currently in production with another 30 planned for 2021."
If they plan to produce 35 electrical JS3s in 2021, I assume that will be most of their production of JS3s. They produced their 100th JS3 last year, 4 years after it was introduced, so up until then average production was around 25 per year.

Of course, they don't have any combustion engine self launch version of the JS3 to compare with, though the heavily delayed JS2 is about to enter production. Don't know any order numbers for that one.


When it comes to 'heavily delayed', nothing can hold a candle to the
GP-14 and 15. In August, we heard they hoped to freeze the overall
design of the units in Q1. As Q1 grinds to an end, wonder what they're
telling aspiring customers now? They've gone uncharacteristically quiet
on social media. The picture of the (former) RK glider sitting in the
snow is getting a bit stale.

On Friday, 19 March 2021 at 03:04:04 UTC, wrote:
On 3/18/2021 7:07 PM, waremark wrote:
When flying the Arcus M with a copilot and no ballast my wing loading is 49 kg/m2 (10 lbs/ft2). In spite of being a 'newer flapped design', in very weak lift pure gliders without ballast simply climb away from me. You may rightly assume that is indicative of my piloting skills, or lack of them!
I wasn't going to say anything...

ArcusM isn't quite as good in weak lift, but anyway it's minimum loading
is MUCH higher than the Jeta; IIRC for me and usual passengers ArcusM
was around 9.5 also. Also Ian's comparing to a non-flapped glider...

It was a different glider in 2020 - when for Covid social distancing reasons I always flew it solo!

https://www.msn.com/en-us/news/techn...?ocid=msedgdhp

This is IT! No more pesky recharging problem.
No more limited self retrieve range!
Sign me up!
Nick
T

On Friday, March 19, 2021 at 8:26:29 PM UTC-4, kinsell wrote:
On 3/12/21 1:38 AM, wrote:
On Friday, 12 March 2021 at 04:33:55 UTC+1, Eric Greenwell wrote:

I don't think it will take 15+ more years for electric gliders to be accepted and desired like
gas powered gliders are now. With FES and mast-mounted electrics available from all the major
manufacturers, I think this year is the "tipping point", and sales of electrics will "soon"
increase faster than the gas powered sales; unfortunately, I don't know of any good way to
track sales.

Just one datapoint, Jonker in their latest newsletter reported the following about their electrical JS3 RES:
"The first 5 JS3 RES gliders are currently in production with another 30 planned for 2021."
If they plan to produce 35 electrical JS3s in 2021, I assume that will be most of their production of JS3s. They produced their 100th JS3 last year, 4 years after it was introduced, so up until then average production was around 25 per year.

Of course, they don't have any combustion engine self launch version of the JS3 to compare with, though the heavily delayed JS2 is about to enter production. Don't know any order numbers for that one.


When it comes to 'heavily delayed', nothing can hold a candle to the
GP-14 and 15. In August, we heard they hoped to freeze the overall
design of the units in Q1. As Q1 grinds to an end, wonder what they're
telling aspiring customers now? They've gone uncharacteristically quiet
on social media. The picture of the (former) RK glider sitting in the
snow is getting a bit stale.

The US rep has sent an update message to those on his circulation list.
UH

On Wednesday, March 31, 2021 at 8:41:34 AM UTC-7, wrote:
https://www.msn.com/en-us/news/techn...?ocid=msedgdhp

Debunked:

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

On 3/31/21 10:12 AM, Hank Nixon wrote:
On Friday, March 19, 2021 at 8:26:29 PM UTC-4, kinsell wrote:
On 3/12/21 1:38 AM, wrote:
On Friday, 12 March 2021 at 04:33:55 UTC+1, Eric Greenwell wrote:

I don't think it will take 15+ more years for electric gliders to be accepted and desired like
gas powered gliders are now. With FES and mast-mounted electrics available from all the major
manufacturers, I think this year is the "tipping point", and sales of electrics will "soon"
increase faster than the gas powered sales; unfortunately, I don't know of any good way to
track sales.

Just one datapoint, Jonker in their latest newsletter reported the following about their electrical JS3 RES:
"The first 5 JS3 RES gliders are currently in production with another 30 planned for 2021."
If they plan to produce 35 electrical JS3s in 2021, I assume that will be most of their production of JS3s. They produced their 100th JS3 last year, 4 years after it was introduced, so up until then average production was around 25 per year.

Of course, they don't have any combustion engine self launch version of the JS3 to compare with, though the heavily delayed JS2 is about to enter production. Don't know any order numbers for that one.


When it comes to 'heavily delayed', nothing can hold a candle to the
GP-14 and 15. In August, we heard they hoped to freeze the overall
design of the units in Q1. As Q1 grinds to an end, wonder what they're
telling aspiring customers now? They've gone uncharacteristically quiet
on social media. The picture of the (former) RK glider sitting in the
snow is getting a bit stale.

The US rep has sent an update message to those on his circulation list.
UH


That's nice. But at some point they need to deliver actual working
gliders. Working gliders that meet their amazing specs would be even
better. Could happen, but their past history does not give one much
hope. I have multiple friends who have these things on order, I hope
it does work out for their sake, but won't be holding my breath. Like
they say, hope is not a strategy.

On Wednesday, March 31, 2021 at 8:41:34 AM UTC-7, wrote:
https://www.msn.com/en-us/news/techn...?ocid=msedgdhp

This is IT! No more pesky recharging problem.
No more limited self retrieve range!
Sign me up!
Nick
T
It's a day early for APRIL FOOLS!

On 3/7/2021 11:30 PM, 2G wrote:
Why don't you start by naming JUST ONE that replaced an ICE with an electric.

Somehow I failed to post this earlier:
Patrick McLaughlin designed/built/debugged/delivered an electric
self-launch version of the Sparrowhawk some years ago (called the Owl).
Not a ICDE replacement, but a scratch-built pylon electric
self-launcher. Of course he's a bit more capable than most of us ;-)