Accident in Namibia, SH Ventus 2cxm

[smfidler]

http://www.az.com.na/unf-lle/schweizer-t-dlich-verungl-ckt.428806

[[email protected]]

Sad news.

Best I can understand the translation, it took several days to locate the wreckage. I would think that *everyone* flying there would be carrying a live tracking device due to the vast and remote area they're flying over.


On Sunday, January 3, 2016 at 12:39:58 PM UTC-8, smfidler wrote:
> http://www.az.com.na/unf-lle/schweizer-t-dlich-verungl-ckt.428806

[smfidler]

It's incredible that at least a sat tracker, and better yet an ELT is not onboard. Even if he landed out safely, the dangers in that region are extreme.

Sad. I wish we all could see the trace. I'm sure it tells the story.

[Charlie M. (UH & 002 owner/pilot)]

On Sunday, January 3, 2016 at 7:21:54 PM UTC-5, smfidler wrote:
> It's incredible that at least a sat tracker, and better yet an ELT is not onboard. Even if he landed out safely, the dangers in that region are extreme.
>
> Sad. I wish we all could see the trace. I'm sure it tells the story.

First, condolences to the pilots family & friends, hope something meaningful is discovered in the investigation. Sad day indeed.

Second, any sort of tracker/ELT is not mentioned, although it may have been there. Have to wait until the final report.

PS, [apologies upfront to peeps that knew the pilot], I figured that "due to who posted this originally" it was a case of a Flarm vs. non-Flarm mid-air and thus justification for full Flarm......

Again, a sad day regardless.

[[email protected]]

I hope that after a good sleep you come to your senses and remove your post script 'UH'. It's never ok to use the death of a fellow aviator to point score. It's pathetic.

CJ

[[email protected]]

On Sunday, January 3, 2016 at 3:39:58 PM UTC-5, smfidler wrote:
> http://www.az.com.na/unf-lle/schweizer-t-dlich-verungl-ckt.428806

Our condolences to family and friends.

https://aviation-safety.net/wikibase/wiki.php?id=182937

[[email protected]]

On Sunday, January 3, 2016 at 2:39:58 PM UTC-6, smfidler wrote:
> http://www.az.com.na/unf-lle/schweizer-t-dlich-verungl-ckt.428806

Thank you Sean, very tragic. Why are they having all those accidents? The article is also referring to the ASH 25 that crashed recently killing two New Zealanders. It is indeed unbelievable that they don't carry satellite trackers.

[smfidler]

Its really sad. The sport is so fun, but the accidents are so tragic. I really think we need to be more open about the causes, share the traces, more promptly share the facts so that we all can understand the reasons and make changes, if mecessary, to our own decision making process.

Was this an error in judgement?

Was is medical? Heat? Long flight?

Did the glider break?

Why no tracker? Did it fail? User Error?

With each accident, huge amounts of information is held close to the chest by many (I have been guilty of this myself) in order to protect themselves, or the feelings of others. I get it...but big picture...shouldnt we all be able to see the IGC traces of any glider accident. No commentary, respect, but the chance to see the general decision making if it was pilot error.

I know these ideas have a snowballs chance in hell. But I wish they were accepted.

I want my trace shared if I am killed in an accident. I want people to learn all that they can from any mistake I make. I will have no ego left to bruise!

Sean

[Christopher Giacomo]

+1 Sean,
The problem, however, almost always comes down pride. Most pilots (students and experienced) that I have instructed with have a difficult time staying non-defensive when their safety margin on a pattern or landing is questioned.
Now extrapolate that out to a situation where there is a very public embarrassment and serious internal questioning of your pilot and decision-making skills, and it starts to become far more understandable that the wreckage we get tossed in the back of the barn and the pilots not want to talk about it until after it has become news. If you are dead, well I guess your ego statement would be accurate, but no surviving family members wants to hear RAS's comments and speculation about their now deceased idiot, nitwit, or whatever otherwise disrespectful term the peanut gallery musters up...If this forum can't respectfully debate whether to partially silence a radar for the spirit of competition, do you really trust them to professionally discuss a decision process that ended in fatality?

In my case (see Oct post), Getting over that first hurdle of internal analysis and self-reflection was the hardest step. Once over that step by discussions with a few very experienced and thoughtful mentors, the public analysis and discussion actually became very helpful and almost therapeutic in "getting over it."

I agree it is incredibly helpful and rare that accident data is shared, but the hardest decision I made during and after my accident was weighing safety and educational benefit with ridicule and reprisal by sharing the story and data on RAS. I am glad that I did, and have already given 2 safety presentations on the accident, but I fully understand why others would not.

Chris
(Formerly "MW")

[Juanman[_2_]]

Terrible news. Having just flown a V2CX in South Africa (with SPOT) I wonder if the pilot was trying to start the engine too low and got into trouble. Hard to tell from the wreck photos. Apparently he went head on, likely from a low altitude spin. Depending on the area in Namibia good places to land out may be few and far between.

Also, the pilot had not logged any flights since his arrival on OLC, which is customary.
More photos of the wreck here:

http://internationalflyerz.co.za/viewtopic.php?t=22363

Juan

On Monday, January 4, 2016 at 1:02:10 PM UTC-5, smfidler wrote:
> Its really sad. The sport is so fun, but the accidents are so tragic. I really think we need to be more open about the causes, share the traces, more promptly share the facts so that we all can understand the reasons and make changes, if mecessary, to our own decision making process.
>
> Was this an error in judgement?
>
> Was is medical? Heat? Long flight?
>
> Did the glider break?
>
> Why no tracker? Did it fail? User Error?
>
> With each accident, huge amounts of information is held close to the chest by many (I have been guilty of this myself) in order to protect themselves, or the feelings of others. I get it...but big picture...shouldnt we all be able to see the IGC traces of any glider accident. No commentary, respect, but the chance to see the general decision making if it was pilot error.
>
> I know these ideas have a snowballs chance in hell. But I wish they were accepted.
>
> I want my trace shared if I am killed in an accident. I want people to learn all that they can from any mistake I make. I will have no ego left to bruise!
>
> Sean

[son_of_flubber]

On Monday, January 4, 2016 at 1:52:46 PM UTC-5, Christopher Giacomo wrote:

> I agree it is incredibly helpful and rare that accident data is shared

I just learned that some of the raw data of an NTSB accident investigation is available

http://dms.ntsb.gov/pubdms/search/projList.cfm

Here is the data on the NTSB docket for Chris's accident.

http://dms.ntsb.gov/pubdms/search/hitlist.cfm?docketID=58063&CFID=251827&CFTOKEN=9a057cd2dc2cdf5b-920D447E-B47F-5B01-CB6063B8EB734D45

There is for example a .pdf map of the flight path, but the IGC log file is not included.

[Christopher Giacomo]

On Monday, January 4, 2016 at 5:06:09 PM UTC-5, son_of_flubber wrote:
> On Monday, January 4, 2016 at 1:52:46 PM UTC-5, Christopher Giacomo wrote:
>
> > I agree it is incredibly helpful and rare that accident data is shared
>
> I just learned that some of the raw data of an NTSB accident investigation is available
>
> http://dms.ntsb.gov/pubdms/search/projList.cfm
>
> Here is the data on the NTSB docket for Chris's accident.
>
> http://dms.ntsb.gov/pubdms/search/hitlist.cfm?docketID=58063&CFID=251827&CFTOKEN=9a057cd2dc2cdf5b-920D447E-B47F-5B01-CB6063B8EB734D45
>
> There is for example a .pdf map of the flight path, but the IGC log file is not included.

Ironic that this would come up...the FAA sent me a nice e-mail today, and 3 months later they have decided with the NTSB that they changed their mind, and bailing out of a glider is now considered an "accident", not an "incident" or "occurrence" as previously thought. Time for some more paperwork...

[smfidler]

Good post Chris. Well put. No easy answers.

Best,

Sean

[Surge]

+1 Sean
I film and log all my flights (position is also streamed in real time to SkyLines and LiveTrack24) so that if something happens people can figure out how I screwed up even if the authorities refuse to release the data or take years to finalize the accident investigation.
The update rate on the live tracking may not capture the last few seconds or there may be spotty coverage but at least people should be able to figure out if I was being stupid enough to scratch around at low altitude and low airspeed a few moments before.

In the absence of reliable eye witnesses all that people can do is speculate but the high speed vertical component in most of these accidents tends to point towards low altitude stall/spin scenarios.

Here are the fatal glider crashes in Namibia and South Africa that I am aware from January 2014 to date.

20th January 2014
Location: Tempe airport, South Africa
Glider: JS1C
Injuries/fatalities: 1 fatality
Pilot experience: The 51 year old Norwegian pilot had over 1000 hours of gliding experience and previously flew F16's in the Norwegian Airforce.
Cause: Stall/spin off an aerotow at 300 feet AGL according to eye witnesses..

24th May 2014
Location: Howick, South Africa
Glider: ASK 13
Injuries/fatalities: 2 fatalities
Pilot experience: A 62 year old with over 30 years flying experience and a 65 year old with more than 10 years flying experience.
Cause: Probably stall and spin from low altitude while ridge soaring.

30th November 2014
Location: Kiripotib, Namibia
Glider: ASH-25-EB-28
Injuries/fatalities: 2 fatalities
Pilot experience: Two very experienced New Zealand pilots aged 66 and 77.
Cause: Unknown

4th October 2015
Location: Potchefstroom, South Africa
Glider: Speed Astir
Injuries/fatalities: 1 fatality
Pilot experience: A 58 year old with 250 flying hours.
Cause: Probably low altitude stall/spin. Pilot was apparently scratching for lift at low altitude close the the airfield.

24th December 2015
Location: Bitterwasser, Namibia
Glider: Ventus 2CX
Injuries/fatalities: 1 fatality
Pilot experience: 46-year-old Swiss pilot. Flying experience unknown.
Cause: Unknown

[Andrzej Kobus]

On Tuesday, January 5, 2016 at 2:10:39 AM UTC-5, Surge wrote:
> +1 Sean
> I film and log all my flights (position is also streamed in real time to SkyLines and LiveTrack24) so that if something happens people can figure out how I screwed up even if the authorities refuse to release the data or take years to finalize the accident investigation.
> The update rate on the live tracking may not capture the last few seconds or there may be spotty coverage but at least people should be able to figure out if I was being stupid enough to scratch around at low altitude and low airspeed a few moments before.
>
> In the absence of reliable eye witnesses all that people can do is speculate but the high speed vertical component in most of these accidents tends to point towards low altitude stall/spin scenarios.
>
> Here are the fatal glider crashes in Namibia and South Africa that I am aware from January 2014 to date.
>
> 20th January 2014
> Location: Tempe airport, South Africa
> Glider: JS1C
> Injuries/fatalities: 1 fatality
> Pilot experience: The 51 year old Norwegian pilot had over 1000 hours of gliding experience and previously flew F16's in the Norwegian Airforce.
> Cause: Stall/spin off an aerotow at 300 feet AGL according to eye witnesses.
>
> 24th May 2014
> Location: Howick, South Africa
> Glider: ASK 13
> Injuries/fatalities: 2 fatalities
> Pilot experience: A 62 year old with over 30 years flying experience and a 65 year old with more than 10 years flying experience.
> Cause: Probably stall and spin from low altitude while ridge soaring.
>
> 30th November 2014
> Location: Kiripotib, Namibia
> Glider: ASH-25-EB-28
> Injuries/fatalities: 2 fatalities
> Pilot experience: Two very experienced New Zealand pilots aged 66 and 77.
> Cause: Unknown
>
> 4th October 2015
> Location: Potchefstroom, South Africa
> Glider: Speed Astir
> Injuries/fatalities: 1 fatality
> Pilot experience: A 58 year old with 250 flying hours.
> Cause: Probably low altitude stall/spin. Pilot was apparently scratching for lift at low altitude close the the airfield.
>
> 24th December 2015
> Location: Bitterwasser, Namibia
> Glider: Ventus 2CX
> Injuries/fatalities: 1 fatality
> Pilot experience: 46-year-old Swiss pilot. Flying experience unknown.
> Cause: Unknown

Surge, is there a report available for the accident on 20th January 2014? If so could you send me a link?

Andrzej

[Surge]

On Wednesday, 6 January 2016 01:01:08 UTC+2, Andrzej Kobus wrote:
> Surge, is there a report available for the accident on 20th January 2014? If so could you send me a link?
>
> Andrzej

Unfortunately the South African CAA hasn't posted the accident report online yet so I can only assume that they're still busy finalising the investigation or they've failed to publish it on their website (neither of which would surprise me).
http://www.caa.co.za/Pages/Accidents%20and%20Incidents/Aircraft-accident-reports.aspx


Eye witnesses report seeing the glider spin in from approximately 300 feet AGL and the tug pilot reported a severe pull on the tow rope which broke.

The only official news was a statement made by the Chairman of Soaring Society of South Africa:

At 12h20 today a 51 year old pilot from Norway was killed in a social gliding accident near Tempe airport. The next of kin was informed telephonically shortly thereafter. The pilot is known as Mr Arent Arntzen and was killed when his aircraft allegedly spun into the ground after breaking the tow rope of the "tug plane" taking the glider up. The Pilot has more than 1000 hours of gliding experience and previously flew F16's in the Norwegian Airforce.

The tug pilot immediately radioed the accident to a passing military helicopter who dropped a paramedic at the scene shortly thereafter. The local flying school operation at Tempe was also contacted and implemented the emergency protocol immediately. It is believed that the pilot was killed on impact. Tempe hosts gliding facilities for Europeans wishing to fly in South Africa for leisure during their winter months.

The Civil Aviation Authority has been contacted and will proceed with an investigation as to the reason for the accident.

Soaring is regarded as one of the safest sports and have a very good track record. Whether the pilot incurred a medical problem, pilot error or equipment failure is best left to the investigation team to discourage speculation.

The Soaring Society of South Africa extends its condolences to the family of the deceased.

Kind regards

Dirk Smit
Chairman of Soaring Society of South Africa - SSSA

[Surge]

According to a post on a private news group, another glider crashed in Namibia on the 11th January 2016.

Evidently it's a D-registered Nimbus 4 (DM?) and the two pilots on board managed to parachute to safety.

Does anyone else know about the accident?

[smfidler]

Wow. Is it just me or is Namibia is experiencing a proportionately large number of accidents?

Be careful over there boys (and girls).

7T

[[email protected]]

According to a friend present at Bitterwasser, the glider went into a kind of spiral dive at 3600 meter altitude. The pilots couldn't get it under control, and the glider lost a wing. The pilots bailed out at 700 and 500 m respectively. One is unharmed, the other has back injuries.

[Jonathan St. Cloud]

Is this an accident with a Nimbus 4D you are speaking of?

On Thursday, January 14, 2016 at 12:52:15 PM UTC-8, wrote:
> According to a friend present at Bitterwasser, the glider went into a kind of spiral dive at 3600 meter altitude. The pilots couldn't get it under control, and the glider lost a wing. The pilots bailed out at 700 and 500 m respectively. One is unharmed, the other has back injuries.

[Surge]

The news of the crash in Namibia on the 11th January 2016 was published yesterday.
http://www.republikein.com.na/ongelukke/n-g-n-sweeftuigongeluk-bitterwasser-lodge.262951

Summary in English:
A French couple bailed out of a Nimbus 4DM (German registered D-KCTI) near the Bitterwasser Lodge, on the 11th January 2016 at 15:40 UTC (16:40 local).

According to the report the left wing dropped while thermalling and recovery was not possible. My assumption is that this was another Nimbus 4 in flight break up during spin recovery.

The 65 year old male sustained minor injuries while the 60 year old woman suffered no injuries. They managed to bail out at about 700 meters AGL.

[WAVEGURU]

"My assumption is that this was another Nimbus 4 in flight break up during spin recovery."

How many of these have there been?

Boggs

[Tango Whisky]

Le vendredi 15 janvier 2016 16:12:36 UTC+1, Waveguru a écrit*:
> "My assumption is that this was another Nimbus 4 in flight break up during spin recovery."
>
> How many of these have there been?
>
> Boggs

Some. Spiral dives and spins with 25m+ gliders go with a huge chance of not being able to recover inside the flight enveloppe. The moment of inertia of these gliders are massively higher than with a 15m/18m glider. They take longer time to stop the rotation, while airspeed increases very rapidly.

Bert
Ventus cM ZW

[WAVEGURU]

How can they get certification if they come apart recovering from a spin?

Boggs

[Tango Whisky]

Le vendredi 15 janvier 2016 17:44:12 UTC+1, Waveguru a écrit*:
> How can they get certification if they come apart recovering from a spin?
>
> Boggs

You can recover from a spin, but you'd need to be sharp. You miss a beat, you'll loose a wing.
Not sure whether a glider >25 m is required to undergo spin testing for certification.

[firsys]

On Sunday, January 3, 2016 at 3:39:58 PM UTC-5, smfidler wrote:
> http://www.az.com.na/unf-lle/schweizer-t-dlich-verungl-ckt.428806

25 m certification; I would chance a guess that the spin recovery
test is done by a very experienced (possibly test) pilot.

John F

An old, no longer bold pilot.

[Jonathan St. Cloud]

Actually my Nimbus 4 was an honest spinner. Once while thermaling in a valley very close to the moutons a gust tried to get a spin developed, normal recovery. Prior to this I had done a number to spin entries followed by normal recovery. I never let a spin develop as i would not in normal flying either. There is a wait time while you wait for a control surface to dig in, but all in all I thought it was honest a normal. I also have several hundred hours in a Nimbus 4D. I found the 4D flew considerabily different than the single seat Nimbus 4.

The rigging is very important on a Nimbus and when I first got mine is was rigged horribly and flew horribly. Fixed the rigging and it was a beauty to fly.

On Friday, January 15, 2016 at 9:01:21 AM UTC-8, Tango Whisky wrote:
> Le vendredi 15 janvier 2016 17:44:12 UTC+1, Waveguru a écrit*:
> > How can they get certification if they come apart recovering from a spin?
> >
> > Boggs
>
> You can recover from a spin, but you'd need to be sharp. You miss a beat, you'll loose a wing.
> Not sure whether a glider >25 m is required to undergo spin testing for certification.

[[email protected]]

Just like any other certified glider according to the European CS-22 norm, a 25+ m glider has to undergo successful spin tests, including tests with asymmetrical water ballast. That's how the Eta glider used for certification broke up some years ago: when getting out of a spin with full ballast in one wing, the other empty, the fuselage couldn't resist the torsional load and failed.

Excerpt from the CS-22 rules:

Spinning

CS 22.221 General

(a) Compliance with the following requirements must be shown in all configurations and, for a powered sailplane, with the engine idling. For sailplanes equipped to carry water ballast, the demonstrations of sub-paragraphs (b) to (g) must also be made for the most critical water ballast asymmetry that might occur due to any single malfunction or due to lateral accelerations during a spin.

(b) The sailplane must be able to recover from spins of at least five turns or such lesser number at which the spin changes into a spiral dive, by applying the controls in a manner normal for recovery and without exceeding either the limiting air-speed nor the limiting positive manoeuvring load factor for the sailplane. Tests must be conducted with wing-flaps and airbrakes neutral (see AMC 22.335) and with:
(1) controls held in the position normal for spins;
(2) ailerons and rudder used in opposite directions;
(3) ailerons applied in the direction of rotation.
In addition and where applicable, tests must be conducted in critical combinations of airbrake extension, wing-flap deflection, waterballast including trim water-ballast and with the powerplant extended or retracted. For wing-flap positions for which a VFE limitation is established, the flap position may be adjusted during recovery after the auto-rotation has stopped. (See AMC 22.221 (b))

(c) A sailplane, in the configurations certificated for intentional spinning, must be able to recover from any point in a spin as defined in CS 22.221(b) in not more than one additional turn. In those configurations not approved for intentional spinning, sub-paragraph (d) must be applied. (See AMC 22.221 (c), (d), (e) and (f))

(d) A sailplane in the configurations not certificated for intentional spinning, must still be able to recover from a spin as defined in CS 22.221(b) in not more than one and a half additional turns. (See AMC 22.221 (c), (d), (e) and (f))

(e) In addition, any sailplane must be able to recover from a one turn spin in any configuration in not more than one additional turn. (See AMC 22.221 (c), (d), (e) and (f))

(f) The loss of altitude from the point at which recovery is initiated to the point at which horizontal flight is first regained must be determined in all of the above mentioned cases. (See AMC 22.221 (c), (d), (e) and (f))

(g) It must be impossible to obtain uncontrollable spins with any use of the controls.

CS 22.223 Spiral dive characteristics
If there is any tendency for the spin to turn into a spiral dive the stage at which this tendency occurs, must be determined. It must be possible to recover from the condition without exceeding either the limiting air speed or the limiting positive maneuvering factor for the sailplane. Compliance with this requirement must be shown without the use of air brakes.

[Jonathan St. Cloud]

Curiously enough the ASH-26E is not certified for spins.


On Friday, January 15, 2016 at 1:51:30 PM UTC-8, wrote:
> Just like any other certified glider according to the European CS-22 norm, a 25+ m glider has to undergo successful spin tests, including tests with asymmetrical water ballast. That's how the Eta glider used for certification broke up some years ago: when getting out of a spin with full ballast in one wing, the other empty, the fuselage couldn't resist the torsional load and failed.
>
> Excerpt from the CS-22 rules:
>
> Spinning
>
> CS 22.221 General
>
> (a) Compliance with the following requirements must be shown in all configurations and, for a powered sailplane, with the engine idling. For sailplanes equipped to carry water ballast, the demonstrations of sub-paragraphs (b) to (g) must also be made for the most critical water ballast asymmetry that might occur due to any single malfunction or due to lateral accelerations during a spin.
>
> (b) The sailplane must be able to recover from spins of at least five turns or such lesser number at which the spin changes into a spiral dive, by applying the controls in a manner normal for recovery and without exceeding either the limiting air-speed nor the limiting positive manoeuvring load factor for the sailplane. Tests must be conducted with wing-flaps and airbrakes neutral (see AMC 22.335) and with:
> (1) controls held in the position normal for spins;
> (2) ailerons and rudder used in opposite directions;
> (3) ailerons applied in the direction of rotation.
> In addition and where applicable, tests must be conducted in critical combinations of airbrake extension, wing-flap deflection, waterballast including trim water-ballast and with the powerplant extended or retracted. For wing-flap positions for which a VFE limitation is established, the flap position may be adjusted during recovery after the auto-rotation has stopped. (See AMC 22.221 (b))
>
> (c) A sailplane, in the configurations certificated for intentional spinning, must be able to recover from any point in a spin as defined in CS 22.221(b) in not more than one additional turn. In those configurations not approved for intentional spinning, sub-paragraph (d) must be applied. (See AMC 22.221 (c), (d), (e) and (f))
>
> (d) A sailplane in the configurations not certificated for intentional spinning, must still be able to recover from a spin as defined in CS 22.221(b) in not more than one and a half additional turns. (See AMC 22.221 (c), (d), (e) and (f))
>
> (e) In addition, any sailplane must be able to recover from a one turn spin in any configuration in not more than one additional turn. (See AMC 22.221 (c), (d), (e) and (f))
>
> (f) The loss of altitude from the point at which recovery is initiated to the point at which horizontal flight is first regained must be determined in all of the above mentioned cases. (See AMC 22.221 (c), (d), (e) and (f))
>
> (g) It must be impossible to obtain uncontrollable spins with any use of the controls.
>
> CS 22.223 Spiral dive characteristics
> If there is any tendency for the spin to turn into a spiral dive the stage at which this tendency occurs, must be determined. It must be possible to recover from the condition without exceeding either the limiting air speed or the limiting positive maneuvering factor for the sailplane. Compliance with this requirement must be shown without the use of air brakes.

[Darryl Ramm]

On Friday, January 15, 2016 at 1:58:38 PM UTC-8, Jonathan St. Cloud wrote:
> Curiously enough the ASH-26E is not certified for spins.

And the reason for that would be, what in Aviation is known as common sense. You want engine oil spilling over a possibly warm/hot exhaust? An engine bay fire?

The ASH-26E handles beautifully, I expect it to recover from a spin very well. Certainly all pushing I have done both with and without an engine installed, it was just great.

[Dave Nadler]

On Friday, January 15, 2016 at 4:51:30 PM UTC-5, wrote:
> ...how the Eta glider used for certification broke up some years ago:
> when getting out of a spin with full ballast in one wing, the other empty,
> the fuselage couldn't resist the torsional load and failed.

I was briefed that the Eta accident was caused by not recognizing
that the spin had degenerated to spiral dive, followed by incorrect
recovery from spiral dive. Was I briefed incorrectly (by a factory
test pilot, briefing me on spin recovery in another make/model)?

Thanks,
Best Regards, Dave

[[email protected]]

On Friday, January 15, 2016 at 2:09:14 PM UTC-8, Darryl Ramm wrote:
> On Friday, January 15, 2016 at 1:58:38 PM UTC-8, Jonathan St. Cloud wrote:
> > Curiously enough the ASH-26E is not certified for spins.
>
> And the reason for that would be, what in Aviation is known as common sense. You want engine oil spilling over a possibly warm/hot exhaust? An engine bay fire?
>
> The ASH-26E handles beautifully, I expect it to recover from a spin very well. Certainly all pushing I have done both with and without an engine installed, it was just great.

I suspect that Schleicher just doesn't want you to do spins, not that it can't. In addition to oil, I wonder if there's a concern that wing mounted water or fuel tanks could expand with the centrifugal force and damage the wing skins?

-tom

[Tango Whisky]

Dave,

your version is correct.

[[email protected]]

Dave is indeed right, but that was not my point, just that the Eta did break up during spin tests.

If you want the whole story, here is the final investigation report:

http://www.bfu-web.de/EN/Publications/Investigation%20Report/2003/Report_03_3X221-Eta-Bueching.pdf?__blob=publicationFile

[Jonathan St. Cloud]

By my count there have been four Nimbus 4D spin/spiral non-recoverable accidents. Two accidents both flight crew were killed and two accidents both flight crew bailed out.

[[email protected]]

On Monday, January 18, 2016 at 12:37:39 PM UTC-8, wrote:
> Dave is indeed right, but that was not my point, just that the Eta did break up during spin tests.
>
> If you want the whole story, here is the final investigation report:
>
> http://www.bfu-web.de/EN/Publications/Investigation%20Report/2003/Report_03_3X221-Eta-Bueching.pdf?__blob=publicationFile

Interesting read. What structural load factors do the sailplane designers use?

[Dan Daly[_2_]]

> Interesting read. What structural load factors do the sailplane designers use?

Google CS-22 Amendment 1 revised. 22.337 refers. Nimbus is Utility.

Dan

[[email protected]]

In Denmark we had a serious incident regarding an Arcus.

The left wing airbrake bell crank ruptured as a consequence of inadequate weld quality. The strength of the welds was insufficient to withstand airbrake bell crank operational loads. The bell crank broke as the glider was in 600ft and had a speed of 108t. The left airbrake extended, The pilot made a brilliant recovery extending the right airbrake and landed the glider 32 seconds later.

You find the full report http://www.hcl.dk/index.php?option=com_contentbuilder&title=søg-luftfart-hclj530-2015-45-bulletin&controller=details&id=3&record_id=426&Itemid=161&limitstart=0&filter_order=&lang=da

-Peter

[smfidler]

Uh oh. That's no good. Has an AD for the Arcus been issued yet? Lots of load on those spoilers for sure.

[Jonathon May[_2_]]

At 17:19 31 January 2016, smfidler wrote:
>Uh oh. That's no good. Has an AD for the Arcus been issued yet? Lots
of
>load on those spoilers for sure.
>

The AD for the duo came out June or July we monitored it and changed to the

new stronger one when the annual was done at Christmas (uk)

[[email protected]]

I was the PIC in the accident involving a Nimbus 4DM in Bitterwasser.
We loose the control of the glider at 3500 meters height and at 110km/h when we wanted to exit a poor left circling thermal.
Why?? I never use the airbrakes. I put the flaps in full negative position and after several spins I tried to stop the dive at very high speed, the two outside wings broke..
We succeed to bail out (less then 15 seconds with the parachute open for me before to reach the ground!)
We spent the afertnoon and the night before the rescue team from Pokweni found us early in the morning.
We wife and me are safe, just spin problems for me.
But I don't know what happends (no water or fuel in the wings).
I hope the investigations will found the reason of this loose of control in a normal flight condition.

[Jonathan St. Cloud]

I wonder if all the Nimbus 4D crashes were from a spin to the left? I know someone who measured the angle of incident on a Nimbus 4DM and he thought the left wing was off by a few degrees. I have no personal knowledge of how the measurements were taken. I have several hundred hours in a Nimbus 4D and Nimbus 4DM. Have about 500ish hours in a Nimbus 4T. Loved those birds.


On Sunday, January 31, 2016 at 11:49:21 AM UTC-8, wrote:
> I was the PIC in the accident involving a Nimbus 4DM in Bitterwasser.
> We loose the control of the glider at 3500 meters height and at 110km/h when we wanted to exit a poor left circling thermal.
> Why?? I never use the airbrakes. I put the flaps in full negative position and after several spins I tried to stop the dive at very high speed, the two outside wings broke..
> We succeed to bail out (less then 15 seconds with the parachute open for me before to reach the ground!)
> We spent the afertnoon and the night before the rescue team from Pokweni found us early in the morning.
> We wife and me are safe, just spin problems for me.
> But I don't know what happends (no water or fuel in the wings).
> I hope the investigations will found the reason of this loose of control in a normal flight condition.

[Jonathan St. Cloud]

I wonder if all the Nimbus 4D crashes were from a spin to the left? Wasn't the Minden crash a spin to the left?



On Sunday, January 31, 2016 at 11:49:21 AM UTC-8, wrote:
> I was the PIC in the accident involving a Nimbus 4DM in Bitterwasser.
> We loose the control of the glider at 3500 meters height and at 110km/h when we wanted to exit a poor left circling thermal.
> Why?? I never use the airbrakes. I put the flaps in full negative position and after several spins I tried to stop the dive at very high speed, the two outside wings broke..
> We succeed to bail out (less then 15 seconds with the parachute open for me before to reach the ground!)
> We spent the afertnoon and the night before the rescue team from Pokweni found us early in the morning.
> We wife and me are safe, just spin problems for me.
> But I don't know what happends (no water or fuel in the wings).
> I hope the investigations will found the reason of this loose of control in a normal flight condition.

[waremark]

On Sunday, 31 January 2016 17:19:59 UTC, smfidler wrote:
> Uh oh. That's no good. Has an AD for the Arcus been issued yet? Lots of load on those spoilers for sure.

For the Arcus, there was a June AD for the inspection of the airbrake bell crank. For my Arcus, the UK agent Southern Sailplanes said the bell cranks were fine when they carried out the inspection.

By the way, there is a Google Group for Arcus operators at https://groups.google.com/forum/#!forum/schempp-hirth-arcus

[Dan Marotta]

Francois,

Thank you for posting about your accident! Do you remember how long
from the loss of control and at what altitude above ground before you
bailed out? Fifteen seconds under canopy seems very close!

Glad you and your wife are OK!

Dan

On 1/31/2016 12:49 PM, wrote:
> I was the PIC in the accident involving a Nimbus 4DM in Bitterwasser.
> We loose the control of the glider at 3500 meters height and at 110km/h when we wanted to exit a poor left circling thermal.
> Why?? I never use the airbrakes. I put the flaps in full negative position and after several spins I tried to stop the dive at very high speed, the two outside wings broke..
> We succeed to bail out (less then 15 seconds with the parachute open for me before to reach the ground!)
> We spent the afertnoon and the night before the rescue team from Pokweni found us early in the morning.
> We wife and me are safe, just spin problems for me.
> But I don't know what happends (no water or fuel in the wings).
> I hope the investigations will found the reason of this loose of control in a normal flight condition.
>
>

--
Dan, 5J

[[email protected]]

At the beginning,at about 3500 meters, when we loose the control of the glider at 110/120 km/h, it was like a flat spin, and it seemed impossible to put the rudder on the right.
After several turns with no success for recovery I put the glider in left classical spin, to a last chance maneuver...
When we exit the spin after several turns we were approximately at 500 meters but with a very high speed, and during the rise the two outside wings went off.
We loose almost 1800 meters (ground about 1200 meters)
François

[Jonathan St. Cloud]

Nimbus 4DM Accident history (loss of control).

- 27/07/1997 Fuentemilanos Spain, 2 fatalities
- 13/07/1999 Minden USA, 2 fatalities
- 13/07/200 Ocana Spain, 1 fatality (4DT)
- 19/11/2006 Zapala Argentina, 2 fatalities
- 22/11/2007 Gariep Dam South Africa, 2 fatalities
- 01/08/2009 Vinon France, 2 fatalities
- 11/01 2016 Bitterwasser Namibia

anyone know the accident history of the ASH-25? I have about 200 hours in Nimbus 4D and 4DM. Have about 500 hours in a Nimbus 4t that I did spin and the single seat nimbus is a beautiful flyer.

[Ramy[_2_]]

Scary! And I don't think there are that many nimbus 4DM out there. Will be interesting to compare this number to number of 4DM made. I wouldn't want to fly one myself.

Ramy

[Steve Leonard[_2_]]

http://rcawsey.co.uk/nimbus4.htm

Scroll down to get the the 4D variants.

Steve Leonard

[Don Johnstone[_4_]]

At 18:23 01 February 2016, Ramy wrote:
>Scary! And I don't think there are that many nimbus 4DM out there.
Will be
>interesting to compare this number to number of 4DM made. I
wouldn't want
>to fly one myself.
>
>Ramy

It would appear that 100 Nimbus 4D were built, of those 11 were 4DT
and 12 were 4D leaving a total of 87 DM of all types.

There is a list of 7 accidents in the previous post due to loss of control.

Just over 8% of the total built have been lost to loss of control
accidents.

I wonder how many other people have to die or parachute to safety
before someone asks the question, should this glider be flying at all.

[[email protected]]

It would be interesting to know the CG location for all of these.

[Tango Whisky]

Le lundi 1 février 2016 20:01:27 UTC+1, Don Johnstone a écrit*:
> At 18:23 01 February 2016, Ramy wrote:
> >Scary! And I don't think there are that many nimbus 4DM out there.
> Will be
> >interesting to compare this number to number of 4DM made. I
> wouldn't want
> >to fly one myself.
> >
> >Ramy
>
> It would appear that 100 Nimbus 4D were built, of those 11 were 4DT
> and 12 were 4D leaving a total of 87 DM of all types.
>
> There is a list of 7 accidents in the previous post due to loss of control.
>
> Just over 8% of the total built have been lost to loss of control
> accidents.
>
> I wonder how many other people have to die or parachute to safety
> before someone asks the question, should this glider be flying at all.

As the N4DM is certified, it had to be demonstrated that it will exit a spin after 3 turn at most.
Loosing 1800 m in any certified glider while trying to stop the spin is hilarious. This corresponds to something like 12-15 turns. Something has gone wrong very seriously.

Bert
Ventus cM TW

[WAVEGURU]

I would rather fly an L-13...

Boggs

[JS]

Thanks for the detail on your accident in Namibia, Francois. It's fantastic that you are here to help us learn from it.
Quite different to intentionally spinning a training glider like ASK21.
Jim

[Don Johnstone[_4_]]

At 20:13 01 February 2016, Tango Whisky wrote:
>Le lundi 1 f=E9vrier 2016 20:01:27 UTC+1, Don Johnstone a
=E9crit=A0:
>> At 18:23 01 February 2016, Ramy wrote:
>> >Scary! And I don't think there are that many nimbus 4DM out
there.=20
>> Will be
>> >interesting to compare this number to number of 4DM made.
I=20
>> wouldn't want
>> >to fly one myself.=20
>> >
>> >Ramy=20
>>=20
>> It would appear that 100 Nimbus 4D were built, of those 11
were 4DT=20
>> and 12 were 4D leaving a total of 87 DM of all types.
>>=20
>> There is a list of 7 accidents in the previous post due to loss of
>contro=
>l.
>> =20
>> Just over 8% of the total built have been lost to loss of
control=20
>> accidents.
>>=20
>> I wonder how many other people have to die or parachute to
safety=20
>> before someone asks the question, should this glider be flying
at all.
>
>As the N4DM is certified, it had to be demonstrated that it will exit
a
>spi=
>n after 3 turn at most.=20
>Loosing 1800 m in any certified glider while trying to stop the
spin is
>hil=
>arious. This corresponds to something like 12-15 turns.
Something has gone
>=
>wrong very seriously.
>
>Bert
>Ventus cM TW
>
Not sure that spinning is the issue per se, it is what happens after
it stops spinning that seems to be the main issue. For whatever
reason it seems that some pilots have had difficulty stopping VNE
being exceeded in the recovery.
A test pilot might be able to demonstrate a successful recovery but
what about mere mortals?

[Charlie M. (UH & 002 owner/pilot)]

On Monday, February 1, 2016 at 4:30:20 PM UTC-5, Don Johnstone wrote:
> At 20:13 01 February 2016, Tango Whisky wrote:
> >Le lundi 1 f=E9vrier 2016 20:01:27 UTC+1, Don Johnstone a
> =E9crit=A0:
> >> At 18:23 01 February 2016, Ramy wrote:
> >> >Scary! And I don't think there are that many nimbus 4DM out
> there.=20
> >> Will be
> >> >interesting to compare this number to number of 4DM made.
> I=20
> >> wouldn't want
> >> >to fly one myself.=20
> >> >
> >> >Ramy=20
> >>=20
> >> It would appear that 100 Nimbus 4D were built, of those 11
> were 4DT=20
> >> and 12 were 4D leaving a total of 87 DM of all types.
> >>=20
> >> There is a list of 7 accidents in the previous post due to loss of
> >contro=
> >l.
> >> =20
> >> Just over 8% of the total built have been lost to loss of
> control=20
> >> accidents.
> >>=20
> >> I wonder how many other people have to die or parachute to
> safety=20
> >> before someone asks the question, should this glider be flying
> at all.
> >
> >As the N4DM is certified, it had to be demonstrated that it will exit
> a
> >spi=
> >n after 3 turn at most.=20
> >Loosing 1800 m in any certified glider while trying to stop the
> spin is
> >hil=
> >arious. This corresponds to something like 12-15 turns.
> Something has gone
> >=
> >wrong very seriously.
> >
> >Bert
> >Ventus cM TW
> >
> Not sure that spinning is the issue per se, it is what happens after
> it stops spinning that seems to be the main issue. For whatever
> reason it seems that some pilots have had difficulty stopping VNE
> being exceeded in the recovery.
> A test pilot might be able to demonstrate a successful recovery but
> what about mere mortals?

Hmmm.... maybe some of these pilots were taught, "Stick fully forward" in the spin recovery vs., "Get the nose below the horizon" instead. In a draggy trainer, they're slow to accelerate so not as much of an issue, in a "clean ship" speed happens very fast comparatively.
Some of this comes to, "Muscle memory" and whether or not good ideas were trained earlier.

I also agree, some ships do markedly different things depending on CG. Curious if there is a common CG (forward, aft?) on the accident ships.

PS, I know none of the involved pilots nor their experience, so I'm sorta guessing here.

[Ramy[_2_]]

On Monday, February 1, 2016 at 11:01:27 AM UTC-8, Don Johnstone wrote:
> At 18:23 01 February 2016, Ramy wrote:
> >Scary! And I don't think there are that many nimbus 4DM out there.
> Will be
> >interesting to compare this number to number of 4DM made. I
> wouldn't want
> >to fly one myself.
> >
> >Ramy
>
> It would appear that 100 Nimbus 4D were built, of those 11 were 4DT
> and 12 were 4D leaving a total of 87 DM of all types.
>
> There is a list of 7 accidents in the previous post due to loss of control.
>
> Just over 8% of the total built have been lost to loss of control
> accidents.
>
> I wonder how many other people have to die or parachute to safety
> before someone asks the question, should this glider be flying at all.

The statistic is probably much worse giving that not all gliders are airworthy and flying from one reason or another.

Ramy

[Paul B[_2_]]

> As the N4DM is certified, it had to be demonstrated that it will exit a spin after 3 turn at most.
> Loosing 1800 m in any certified glider while trying to stop the spin is hilarious.

Maybe not if you in it. But I do see your point, was a spiral mistaken for a spin?

Cheers

Paul


This corresponds to something like 12-15 turns. Something has gone wrong very seriously.
>
> Bert
> Ventus cM TW

[BruceGreeff]

The very long wing open class gliders have a bad record on spin recovery.
They will generally transition to a spiral dive quite early in a spin,
but will accelerate very rapidly on the exit.
If they do get into a stable spin, the momentum in the wings is a problem.

If you have water in the wings, or fuel, then you are a test pilot.
Certification is done dry.

There are at least five Nimbus 4D accidents I am aware of where recovery
was past Vne and the glider broke up on recovery. Ash25 - same story.

Bruce

On 2016-02-02 08:12, Paul B wrote:
>
>> As the N4DM is certified, it had to be demonstrated that it will exit a spin after 3 turn at most.
>> Loosing 1800 m in any certified glider while trying to stop the spin is hilarious.
>
> Maybe not if you in it. But I do see your point, was a spiral mistaken for a spin?
>
> Cheers
>
> Paul
>
>
> This corresponds to something like 12-15 turns. Something has gone wrong very seriously.
>>
>> Bert
>> Ventus cM TW
>

--
Bruce Greeff
T59D #1771

[[email protected]]

Le vendredi 15 janvier 2016 22:07:57 UTC+1, Jonathan St. Cloud a écrit :
> > The rigging is very important on a Nimbus and when I first got mine is was rigged horribly and flew horribly. Fixed the rigging and it was a beauty to fly.
>

Hi Jonathan,
Very interesting. I have a N4DM since 17 years and 2.500 hours and see no possibility at all to change any setting during rigging. I can't understand how I may "rig horribly"... Thanks for explaining to me and others.
Instead, I can change the setting of the flap angle and the force of airbrake locking by changing the extension of the controls between the fuselage and the inner wing, but this is something that takes time and attention, not simply a rigging. BTW, I actually change the airbrake locking force twice a year, for cold flights in Patagonia and warm ones in Europe. See my book "Dancing with the Wind" page 194 and following (on sale at Cumulus Soaring)..
All the best
jm

[[email protected]]

Le lundi 1 février 2016 20:01:27 UTC+1, Don Johnstone a écrit*:
> At 18:23 01 February 2016, Ramy wrote:
> > There is a list of 7 accidents in the previous post due to loss of control.
> Just over 8% of the total built have been lost to loss of control
> accidents.
> I wonder how many other people have to die or parachute to safety
> before someone asks the question, should this glider be flying at all.

That's not totally true.
- Spain: wrong decision (turn back) after engine failure after take off
- Zapala: hitting the rocks at low altitude in turbulent blue thermal day

Vinon 2009 was actually loss of control in spiral dive, inexperienced crew.
Bitterwasser 2016, the future will tell (the crew is alive and is professional).
The others, I don't know.

These gliders cannot undergo a spin or a spiral dive without an almost certain fatal issue (in particular if they have an engine), unless you are an expert test pilot. I was forced to do that in an ASH25E twenty years ago and although I could stop the spin after less than a turn, the recovery was above Vne and the fuselage was over the vertical position (i.e. slightly negative). I said NEVER again!

In the case of the N4D, it happens that the airbrakes will self-open (photo available) during the pull-up due to both the high lift force and the kinematics of the control rod. No way to avoid loosing the outer wings. Amazingly, I have flown 2 500 hrs in my N4DM, almost at the maximum rear CG, and could never enter a involuntary spin, but twice the beginning of a spiral dive because the inexperienced pilot tried to recover using the opposite aileron and pulling, promptly recovered with stick in the middle and little forward, and full opposite rudder, exit at Vne.

Big ships are like this, if you don't like, don't buy!

All the best,
jmc

[Bruce Hoult]

On Tuesday, February 2, 2016 at 11:58:17 AM UTC+3, wrote:
> Le vendredi 15 janvier 2016 22:07:57 UTC+1, Jonathan St. Cloud a écrit :
> > > The rigging is very important on a Nimbus and when I first got mine is was rigged horribly and flew horribly. Fixed the rigging and it was a beauty to fly.
> >
>
> Hi Jonathan,
> Very interesting. I have a N4DM since 17 years and 2.500 hours and see no possibility at all to change any setting during rigging. I can't understand how I may "rig horribly"... Thanks for explaining to me and others.
> Instead, I can change the setting of the flap angle and the force of airbrake locking by changing the extension of the controls between the fuselage and the inner wing, but this is something that takes time and attention, not simply a rigging. BTW, I actually change the airbrake locking force twice a year, for cold flights in Patagonia and warm ones in Europe. See my book "Dancing with the Wind" page 194 and following (on sale at Cumulus Soaring).

"Rigging" is a set of devices for adjusting positions, angles, tensions etc of aerodynamic surfaces -- or as a verb the use of such adjustments. Originally from sailing ships but later applied to aircraft (which were initially made in very similar ways. The "rigging angle", for example, refers to the angle between the chord of the wing and the fuselage.

What we refer to as "rigging" of gliders is merely the use of precision quick-release mechanisms that are expressly designed to not alter the settings!

[Eric Munk]

At 16:34 01 February 2016, Jonathan St. Cloud wrote:
>Nimbus 4DM Accident history (loss of control).
>
>- 27/07/1997 Fuentemilanos Spain, 2 fatalities
>- 13/07/1999 Minden USA, 2 fatalities
>- 13/07/200 Ocana Spain, 1 fatality (4DT)
>- 19/11/2006 Zapala Argentina, 2 fatalities
>- 22/11/2007 Gariep Dam South Africa, 2 fatalities
>- 01/08/2009 Vinon France, 2 fatalities
>- 11/01 2016 Bitterwasser Namibia
>
>anyone know the accident history of the ASH-25? I have about 200 hours in
>Nimbus 4D and 4DM. Have about 500 hours in a Nimbus 4t that I did spin
and
>the single seat nimbus is a beautiful flyer.
>

Loss of control is a wide category. I know one of the above is a winch
launch gone sour. Not much to do with spinning charachteristics...

[James Thomson[_2_]]

At 11:02 02 February 2016, Bruce Hoult wrote:

>"Rigging" is a set of devices for adjusting positions, angles, tensions
>etc=
> of aerodynamic surfaces -- or as a verb the use of such
adjustments.
>Origi=
>nally from sailing ships but later applied to aircraft (which were
>initiall=
>y made in very similar ways. The "rigging angle", for example, refers
to
>th=
>e angle between the chord of the wing and the fuselage.
>
>What we refer to as "rigging" of gliders is merely the use of precision
>qui=
>ck-release mechanisms that are expressly designed to not alter the
>settings=
>!
Rigging could be referring to control deflections. These are not
affected by the operation pilots call "rigging" but they can, and do,
change due to wear and to the replacement of parts in the control
linkages. They are adjustable by maintenance personnel. If the
deflections are wrong the glider will not handle as designed and
expected.

Under BGA rules the control deflections on all gliders have to be
checked (and corrected if wrong) at every annual inspection. I expect
other authorities have similar rules.

[Dan Daly[_2_]]

On Tuesday, February 2, 2016 at 3:41:35 AM UTC-5, BruceGreeff wrote:
> The very long wing open class gliders have a bad record on spin recovery.
> They will generally transition to a spiral dive quite early in a spin,
> but will accelerate very rapidly on the exit.
> If they do get into a stable spin, the momentum in the wings is a problem.
>
> If you have water in the wings, or fuel, then you are a test pilot.
> Certification is done dry.
>
> There are at least five Nimbus 4D accidents I am aware of where recovery
> was past Vne and the glider broke up on recovery. Ash25 - same story.
>
> Bruce

> Bruce Greeff
> T59D #1771

"Certification is done dry..." No. Current CS-22 Amendment 1:

"CS 22.221 General
(a) Compliance with the following requirements must be shown in all configurations and, for a powered sailplane, with the engine idling.
For sailplanes equipped to carry water ballast, the demonstrations of sub-paragraphs (b) to (g) must also be made for the most critical water ballast asymmetry that might occur due to any single malfunction or due to lateral accelerations during a spin."

Then, in spin testing (later in CS22 AL1):
"AMC 22.221(b)
Spinning
General
It will normally be sufficient to conduct a number of spins of about two turns in each of the conditions of CS 22.221(b) and subsequently to conduct spins of five turns in the most adverse cases."

You may recall the ETA spin test with one wing full/one empty led to a crash. Both CS-22 AL1 and the ETA test are available by mr. google.

[Bruce Hoult]

On Tuesday, February 2, 2016 at 3:47:08 PM UTC+3, James Thomson wrote:
> At 11:02 02 February 2016, Bruce Hoult wrote:
>
> >"Rigging" is a set of devices for adjusting positions, angles, tensions
> >etc=
> > of aerodynamic surfaces -- or as a verb the use of such
> adjustments.
> >Origi=
> >nally from sailing ships but later applied to aircraft (which were
> >initiall=
> >y made in very similar ways. The "rigging angle", for example, refers
> to
> >th=
> >e angle between the chord of the wing and the fuselage.
> >
> >What we refer to as "rigging" of gliders is merely the use of precision
> >qui=
> >ck-release mechanisms that are expressly designed to not alter the
> >settings=
> >!
> Rigging could be referring to control deflections. These are not
> affected by the operation pilots call "rigging" but they can, and do,
> change due to wear and to the replacement of parts in the control
> linkages. They are adjustable by maintenance personnel. If the
> deflections are wrong the glider will not handle as designed and
> expected.

My point, precisely.

[Tango Whisky]

Le mardi 2 février 2016 13:41:43 UTC+1, Dan Daly a écrit*:

> You may recall the ETA spin test with one wing full/one empty led to a crash. Both CS-22 AL1 and the ETA test are available by mr. google.

No. The Eta crashed when trying to recover from a spiral dive (dry). The load on the rudder simply snapped the tail boom.

The ASH25 did crash during flight testing when spinning with water in only one wing. The centrifugal force of the water made the wing skin pop, and Martin Heide had to parachute down. He had been suspicious about this outcome beforehand and had tried to talk authorities into dropping this part of the test, but to no avail. So he did the test starting at 10'000 ft.

[Dan Daly[_2_]]

On Tuesday, February 2, 2016 at 8:48:43 AM UTC-5, Tango Whisky wrote:
> Le mardi 2 février 2016 13:41:43 UTC+1, Dan Daly a écrit*:
>
> > You may recall the ETA spin test with one wing full/one empty led to a crash. Both CS-22 AL1 and the ETA test are available by mr. google.
>
> No. The Eta crashed when trying to recover from a spiral dive (dry). The load on the rudder simply snapped the tail boom.
>
> The ASH25 did crash during flight testing when spinning with water in only one wing. The centrifugal force of the water made the wing skin pop, and Martin Heide had to parachute down. He had been suspicious about this outcome beforehand and had tried to talk authorities into dropping this part of the test, but to no avail. So he did the test starting at 10'000 ft.

******
According to the Oct 2009 BFU Investigative report 3x221-0/05, the test was a spinning trial with asymmetric fuel (not water as I said - you are correct on that) - page 1 (History of the flight). According to the conclusions, the spin changed to a spiral dive and the use of rudder for recovery broke the tail (page 5). I guess we are both right, and both wrong in some parts! The asymmetric condition was not noted in conclusions, so probably not critical in comparison to the engineering conclusions.

I didn't say anything about ASH25 but it sounds interesting... I did a brief search but couldn't find it online. When did it happen?

Thank you for the correction.

[Tango Whisky]

Le mardi 2 février 2016 15:59:41 UTC+1, Dan Daly a écrit*:
> On Tuesday, February 2, 2016 at 8:48:43 AM UTC-5, Tango Whisky wrote:
> > Le mardi 2 février 2016 13:41:43 UTC+1, Dan Daly a écrit*:
> >
> > > You may recall the ETA spin test with one wing full/one empty led to a crash. Both CS-22 AL1 and the ETA test are available by mr. google.
> >
> > No. The Eta crashed when trying to recover from a spiral dive (dry). The load on the rudder simply snapped the tail boom.
> >
> > The ASH25 did crash during flight testing when spinning with water in only one wing. The centrifugal force of the water made the wing skin pop, and Martin Heide had to parachute down. He had been suspicious about this outcome beforehand and had tried to talk authorities into dropping this part of the test, but to no avail. So he did the test starting at 10'000 ft.
>
> ******
> According to the Oct 2009 BFU Investigative report 3x221-0/05, the test was a spinning trial with asymmetric fuel (not water as I said - you are correct on that) - page 1 (History of the flight). According to the conclusions, the spin changed to a spiral dive and the use of rudder for recovery broke the tail (page 5). I guess we are both right, and both wrong in some parts! The asymmetric condition was not noted in conclusions, so probably not critical in comparison to the engineering conclusions.
>
> I didn't say anything about ASH25 but it sounds interesting... I did a brief search but couldn't find it online. When did it happen?
>
> Thank you for the correction.

I think that the ASH25 happened in 1985 or 1986. Martin Heide told me about it a week or two later.

[Jonathan St. Cloud]

Ailerons, flaps and mixing was rigged wrong. Once that was corrected she was a beauty. Recovered from spin entry within quarter turn of control inputs, dry. Single place Nimbus 4. I still miss that bird!

On Tuesday, February 2, 2016 at 12:58:17 AM UTC-8, wrote:
> Le vendredi 15 janvier 2016 22:07:57 UTC+1, Jonathan St. Cloud a écrit :
> > > The rigging is very important on a Nimbus and when I first got mine is was rigged horribly and flew horribly. Fixed the rigging and it was a beauty to fly.
> >
>
> Hi Jonathan,
> Very interesting. I have a N4DM since 17 years and 2.500 hours and see no possibility at all to change any setting during rigging. I can't understand how I may "rig horribly"... Thanks for explaining to me and others.
> Instead, I can change the setting of the flap angle and the force of airbrake locking by changing the extension of the controls between the fuselage and the inner wing, but this is something that takes time and attention, not simply a rigging. BTW, I actually change the airbrake locking force twice a year, for cold flights in Patagonia and warm ones in Europe. See my book "Dancing with the Wind" page 194 and following (on sale at Cumulus Soaring).
> All the best
> jm

[[email protected]]

Read my post, at the begining it was not a spin

[Jonathan St. Cloud]

This comment has nothing to do with the latest Nimbus 4DM accident:

However, in regards to some comments about a glider spin developing into a spiral. If you have not had that happen it can be a real surprise. I was spin training in a 2-32 that would do 1/2 turn in a spin and then go in spiral. The sight picture was the same, only different was rudder opposite the rotation did not work. I spotted the problem after about ¾ of a rotation but was very surprised that the spiral did not look any different than the spin I had always assumed I could tell the difference. Now picture this is a slippery modern glider of any wing length, nose 70 degrees down or more. Would very quickly go through VNE.

The most fun flying I have done is in a Nimbus 4D or ASH-25 as a shared experience is the essence of human nature. Two pilots can make one very good flight!

[Andrzej Kobus]

On Tuesday, February 2, 2016 at 5:02:50 PM UTC-5, Jonathan St. Cloud wrote:
> This comment has nothing to do with the latest Nimbus 4DM accident:
>
> However, in regards to some comments about a glider spin developing into a spiral. If you have not had that happen it can be a real surprise. I was spin training in a 2-32 that would do 1/2 turn in a spin and then go in spiral. The sight picture was the same, only different was rudder opposite the rotation did not work. I spotted the problem after about ¾ of a rotation but was very surprised that the spiral did not look any different than the spin I had always assumed I could tell the difference. Now picture this is a slippery modern glider of any wing length, nose 70 degrees down or more. Would very quickly go through VNE.
>
> The most fun flying I have done is in a Nimbus 4D or ASH-25 as a shared experience is the essence of human nature. Two pilots can make one very good flight!

You should be able to tell the difference. Look at your airspeed indicator. In the spin the air speed will be low or at least stable and in the spiral it will be high and quickly increasing. That was the case on all gliders I spanned. Turn and bank indicator ball in the spin will be all the way to the outside of the turn.

[Jonathan St. Cloud]

The 2-32 is not very slippery, no need to look inside when spin recovery did not work, I recovered from the spiral. Point being, if you had not considered this possibility and are in a slippery glider you might keep this in mind. This is the only aircraft I had intentional spun that would spiral out of the spin.



On Tuesday, February 2, 2016 at 3:05:29 PM UTC-8, Andrzej Kobus wrote:

> You should be able to tell the difference. Look at your airspeed indicator. In the spin the air speed will be low or at least stable and in the spiral it will be high and quickly increasing. That was the case on all gliders I spanned. Turn and bank indicator ball in the spin will be all the way to the outside of the turn.

[BobW]

On 2/2/2016 7:46 PM, Jonathan St. Cloud wrote:
> The 2-32 is not very slippery, no need to look inside when spin recovery
> did not work, I recovered from the spiral. Point being, if you had not
> considered this possibility and are in a slippery glider you might keep
> this in mind. This is the only aircraft I had intentional spun that would
> spiral out of the spin.
>
>
>
> On Tuesday, February 2, 2016 at 3:05:29 PM UTC-8, Andrzej Kobus wrote:
>
>> You should be able to tell the difference. Look at your airspeed
>> indicator. In the spin the air speed will be low or at least stable and
>> in the spiral it will be high and quickly increasing. That was the case
>> on all gliders I spanned. Turn and bank indicator ball in the spin will
>> be all the way to the outside of the turn.

Having never spun anything more slippery than a 2-32 (at least four of which
have been spun into the ground from well aloft), but having many times
incipiently-spun a 15-meter glass bird, and having thoroughly spun a 1-26 (in
both directions) for up to 17 turns (in one direction only), and having gained
a modicum of knowledge concerning aeronautical industry practices and war
stories related to spinning, I long ago concluded several things about spins:
1) they were then (and remain) beyond mankind's computational skills regarding
"absolutely-predictable behavior," and (along with flutter testing) rightfully
are one of the reasons within industry that test-piloting remains a
well-respected, and reasonably well-paying occupation; 2) anyone who treats
them complacently is either seriously ignorant or willfully blind; and 3) just
because a bird is certified is no reason to complacently bet your life on the
*next* spin behaving identically to past spins. I'm not trying to be dramatic
here, just trying to convey the very real complexity of spinning aerodynamics.

My present working conclusion is big, heavy, clean sailplanes (e.g. ASH-25,
Nimbus 4DM) may well (likely do, for cleanliness & inertial reasons) have less
"ham-fisted margin" between the time of stopping rotation and returning to
level flight than "the rest of the glider fleet." Thoughtful pilots will fly
them accordionly...

As to "looking inside at ASI/needle-ball" to verify whether one is in a spin
or spiral dive, I'd hesitate to make a sweeping claim one does or does not
have to, but - assuming for the sake of discussion that ground clearance isn't
an issue - if you choose wrongly as to which methodology to apply first in the
face of "WTF is the ship doing?" I know I'd rather apply spiral dive
corrective action *before* anti-spin corrective action, simply because being
late on the former includes dire structural implications. Best, of course, to
have confirmed what the ship is doing before attempting corrective action, and
instruments are (used to be, anyway) a part of every instructors' teaching
toolkit.

I could never get that (still in the flying fleet) 1-26 I spent so much time
with investigating its spinning behavior, to remain in a spin in one direction
(I've forgotten which) for more than 5 (sometimes less than 3) turns;
throughout it "hunted up/down in pitch" in phase with decreasing/increasing
spin rate until on one of its downward-pitching excursions, it always exited
in a skidding diving turn which showed every indication was about to become a
spiral dive if left unaddressed. It spun rock-steadily in the other direction,
but required ailerons to be strictly neutralized to avoid more or less
instantly exiting in either a nose-low slipping turn (aileron out of the spin)
or a nose-low skidding spiral dive (aileron into the spin). The transition
from spinning flight to non-spinning flight was attention grabbing in that
aerodynamically dirty bird. Quite audible and accompanied by obvious lateral
accelerations. I never could convince myself to permit the skidding spiral
dive entry aft-stick recovery to continue to nose level without quickly
neutralizing the ailerons so cautious was I of spiral dive possibilities,
though I think it would have safely recovered at that early stage of things.
My "spin-now-stopped" recoveries involved rapidly neutralizing ailerons and
maintaining full aft stick. I never managed to induce a secondary stall under
those circumstances in that docile, forgiving, ship.

The transition from spinning to non-spinning flight may well *not* be obvious
in some other ship. You pays your money and takes your chances with spin
behavior, ideally treading thoughtfully, cautiously and preparedly...

Bob - so call me overcautious - W.

[Don Johnstone[_4_]]

As glider pilots there are many things we do which are familiar to
us, we deal with these events very quickly, the so called muscle
memory. If we are prudent we practise, on a regular basis so
emergency situations, such as launch failures and every one we
practise increases the chance of recognition and proper recovery
action.

As regards spinning we may practise in a glider cleared for
intentional spinning but we seldom if ever practise a spiral dive
which is uncontrolled, we have no experience of such an event. We
may have been told that it can happen, briefed on the symptoms
and warned of the consequences but never actually seen it and
recovered unless we are one of the very few test pilots.

The difference between a spiral dive and a spin may be bleedin
obvious to a few but for most of us it is a situation which requires
the processing of information which is completely unfamiliar.

Some gliders are prohibited from deliberate spinning so we never
have the opportunity to practice, it is likely therefore that the first
time we see an event be it spinning or spiral dive is when it occurs
unintentionally. One of the symptoms which distinguishes a spiral
dive from a spin is the already high and increasing airspeed. To
recognise the difference you have to see it. The problem is that the
increase in airspeed, the acceleration, is very high, maybe
approaching 18kts per second per second (32fps/ps). If we take
just 3 seconds to see that the speed is in fact increasing we will
have added 57kts and we still have to decide how to correct that
and take the appropriate action. If we take a further 3 seconds to
decide on and start to carry out the appropriate recovery we are
already through VA, approaching or exceeding VNE and headed for
the scene of the accident. It has been said that recovery will result
in uncommanded airbrake deployment which transfers and
increased load to the outer wing panels, which are likely to fail.

When a test pilot carries out his tests he deliberately does so, he
knows what to expect and has already decided on his recovery
action, his recovery is likely to be close to optimum. He is likely to
guard the airbrake control. I would suggest that anyone, including
our test pilot might have difficulty if the event was completely
unexpected.

Even if the acceleration is only 90% of the maximun in a Nimbus
4DM, the speed will increase by 100kts in the 6 seconds. Assuming
we started with 50kts the recovery will go through VNE (177kts).
Max manouvering speed (VA) for a Nimbus 4 is 100kts, so full
control deflection is not available after 3 seconds. It seems to me
that if it happens unexpectedly it is not going to end well however
lighting fast our reactions might be.

[Justin Craig[_3_]]

Don,

the answer is simple. Don't fly a Nimbus 4 if you do not feel competent to
do so.

There is a sh1t load of opinions in this thread and some frankly outlandish
comments from people (most of whom) have not flown the aircraft.

"I wonder how many other people have to die or parachute to safety
before someone asks the question, should this glider be flying at all"

A knee jerk response to a factually correct but ill-informed statement
which lacked all of the information.

So far as I can see, there are two people on this thread who has
constructively contributed. JMC and Francois.

I would happily fly a Nimbus 4DM with either of these people.




At 11:05 03 February 2016, Don Johnstone wrote:
>As glider pilots there are many things we do which are familiar to
>us, we deal with these events very quickly, the so called muscle
>memory. If we are prudent we practise, on a regular basis so
>emergency situations, such as launch failures and every one we
>practise increases the chance of recognition and proper recovery
>action.
>
>As regards spinning we may practise in a glider cleared for
>intentional spinning but we seldom if ever practise a spiral dive
>which is uncontrolled, we have no experience of such an event. We
>may have been told that it can happen, briefed on the symptoms
>and warned of the consequences but never actually seen it and
>recovered unless we are one of the very few test pilots.
>
>The difference between a spiral dive and a spin may be bleedin
>obvious to a few but for most of us it is a situation which requires
>the processing of information which is completely unfamiliar.
>
>Some gliders are prohibited from deliberate spinning so we never
>have the opportunity to practice, it is likely therefore that the first
>time we see an event be it spinning or spiral dive is when it occurs
>unintentionally. One of the symptoms which distinguishes a spiral
>dive from a spin is the already high and increasing airspeed. To
>recognise the difference you have to see it. The problem is that the
>increase in airspeed, the acceleration, is very high, maybe
>approaching 18kts per second per second (32fps/ps). If we take
>just 3 seconds to see that the speed is in fact increasing we will
>have added 57kts and we still have to decide how to correct that
>and take the appropriate action. If we take a further 3 seconds to
>decide on and start to carry out the appropriate recovery we are
>already through VA, approaching or exceeding VNE and headed for
>the scene of the accident. It has been said that recovery will result
>in uncommanded airbrake deployment which transfers and
>increased load to the outer wing panels, which are likely to fail.
>
>When a test pilot carries out his tests he deliberately does so, he
>knows what to expect and has already decided on his recovery
>action, his recovery is likely to be close to optimum. He is likely to
>guard the airbrake control. I would suggest that anyone, including
>our test pilot might have difficulty if the event was completely
>unexpected.
>
>Even if the acceleration is only 90% of the maximun in a Nimbus
>4DM, the speed will increase by 100kts in the 6 seconds. Assuming
>we started with 50kts the recovery will go through VNE (177kts).
>Max manouvering speed (VA) for a Nimbus 4 is 100kts, so full
>control deflection is not available after 3 seconds. It seems to me
>that if it happens unexpectedly it is not going to end well however
>lighting fast our reactions might be.
>
>

[Eric Munk]

At 11:05 03 February 2016, Don Johnstone wrote:
>The difference between a spiral dive and a spin may be bleedin
>obvious to a few but for most of us it is a situation which requires
>the processing of information which is completely unfamiliar.

The instruction standard I teach by mandates spiral dive and spin recovery
prior to first solo. Common sense dictates that if you can't distinguish
between the two in your day-to-day glider (and their very different
recoveries), you shouldn't fly solo IMHO. Granted, the differences are a
lot more subtle in an advanced (open class) glider (and time to react a lot
shorter), but it still suprises me how often students confuse the two and
put in the wrong control inputs.

[Tango Whisky]

Le mercredi 3 février 2016 13:15:10 UTC+1, Justin Craig a écrit*:
> Don,
>
> the answer is simple. Don't fly a Nimbus 4 if you do not feel competent to
> do so.

Justin,

"feeling competent to" is probably he cause of death #1 amongst glider pilots.

I absolutely agree with you that if one doesn't feel competent to fly an open glass glider, then he shouldn't. But "feeling compentent" might be a different thing than "being competent".
I'm not addressing that to any person in specific. However, having spin experience in a ASK21 or a Discus does not mean that you will survive a fully developed spin in an open glass ship. The momentum of the wing is about 3-5 times larger than that of a 15m glider, and when you do the right inputs to stop the spin, the large momentum means that until the actual rotation is stopped, you are accelerating nose down by 70-80 deg with negative flaps for almost a full turn. So if you wait for the rotation to have stopped before you pull up, there is almost no way that the wings would stay with you. If you don't wait long enough, you might re-stall the wing. The margin for a successful exit is very slim, while on a 15 m ship it is absolutely easy.

Been there, done that long ago on a 26 m ship, happy to be still alive. After that event, any incipent stall on a ASH25 got my immediate attention.

[Andreas Maurer]

On Tue, 2 Feb 2016 07:12:13 -0800 (PST), Tango Whisky
> wrote:

>I think that the ASH25 happened in 1985 or 1986. Martin Heide told me about it a week or two later.

.... actually it was the ASW-22 prototype.

[Dave Nadler]

On Wednesday, February 3, 2016 at 10:41:22 AM UTC-5, Andreas Maurer wrote:
> On Tue, 2 Feb 2016 07:12:13 -0800 (PST), Tango Whisky
> > wrote:
> >I think that the ASH25 happened in 1985 or 1986.
> > Martin Heide told me about it a week or two later.
>
> ... actually it was the ASW-22 prototype.

Right, one of two accidents I know of where hydrostatic pressure
blew the wing skins off a -22 (the other a ground-loop).

Led to development of the kludgy isolated tanks, which limit
hydraulic pressure *IFF* there's a bit of air in the tanks.
Don't overfill ;-)

Hope that helps,
Best Regards, Dave

[Ross[_3_]]

Just going back to the actual topic of this thread, there has been a trace received from the logger of the Ventus in question.
Looks like he exited the thermal at a bit over 4500 meters, and has gently pulled into a turn, stalled, and gone straight down from there. No sign of a recovery.
I will not speculate as to what has happened as he was a friend of mine.

[Surge]

One wonders if the inclusion of a tail parachute would have been a better option on these slippery open class ships with tricky recovery envelopes?
Accidental or unreliable deployment issues aside, a drag chute could probably be used to recover from a spin or spiral dive without exceeding Vne.

For example the Nimbus 2 has a terminal velocity in a vertical dive of 200 to 220 km/h (108 to 119 knots) with the tail chute deployed, air brakes and landing gear extended. So assuming one popped the chute within a couple of seconds (giving extra time to extend air brakes and lower the landing gear) the glider would be able to exit the spin/spiral vertically and then gently pull out of the dive without breaking anything in the process.

Is this a crazy idea or feasible?

[son_of_flubber]

On Thursday, February 4, 2016 at 3:32:51 AM UTC-5, Surge wrote:
> One wonders if the inclusion of a tail parachute would have been a better option on these slippery open class ships with tricky recovery envelopes?

You would need a reliable means to jettison the chute at the right moment.

[[email protected]]

On Thursday, February 4, 2016 at 10:32:26 AM UTC-5, son_of_flubber wrote:
> On Thursday, February 4, 2016 at 3:32:51 AM UTC-5, Surge wrote:
> > One wonders if the inclusion of a tail parachute would have been a better option on these slippery open class ships with tricky recovery envelopes?
>
> You would need a reliable means to jettison the chute at the right moment.

You mean like the other gliders that have tail chutes?
UH

[Jim White[_3_]]

At 15:32 04 February 2016, son_of_flubber wrote:
>On Thursday, February 4, 2016 at 3:32:51 AM UTC-5, Surge wrote:
>> One wonders if the inclusion of a tail parachute would have been a
better
>option on these slippery open class ships with tricky recovery envelopes?
>
>You would need a reliable means to jettison the chute at the right
moment.
>

Attach the rear seat pilot to the boom with a length of cable. He can then
exit and deploy his chute thereby stabilising the spin and when the
aircraft is fully recovered disconnect and float down to earth. Job done!

[Bruce Hoult]

On Thursday, February 4, 2016 at 6:32:26 PM UTC+3, son_of_flubber wrote:
> On Thursday, February 4, 2016 at 3:32:51 AM UTC-5, Surge wrote:
> > One wonders if the inclusion of a tail parachute would have been a better option on these slippery open class ships with tricky recovery envelopes?
>
> You would need a reliable means to jettison the chute at the right moment.

Like the blue knob low on the right hand cockpit wall in my glider here, you mean?

http://hoult.org/bruce/gliding/sasha/sasha-Images/3.jpg.

First stop deploys the chute. Zig right and all the way forward to jettison it.

Not the same glider, but looks like the same model:

https://farm8.staticflickr.com/7261/7545310106_818173ceca_b.jpg

[Dan Marotta]

How does that work? Do you push the knob forward to the detent to
deploy the chute and then outboard and forward again to jettison? What
type of glider is that?

On 2/4/2016 9:02 AM, Bruce Hoult wrote:
> On Thursday, February 4, 2016 at 6:32:26 PM UTC+3, son_of_flubber wrote:
>> On Thursday, February 4, 2016 at 3:32:51 AM UTC-5, Surge wrote:
>>> One wonders if the inclusion of a tail parachute would have been a better option on these slippery open class ships with tricky recovery envelopes?
>> You would need a reliable means to jettison the chute at the right moment.
> Like the blue knob low on the right hand cockpit wall in my glider here, you mean?
>
> http://hoult.org/bruce/gliding/sasha/sasha-Images/3.jpg.
>
> First stop deploys the chute. Zig right and all the way forward to jettison it.
>
> Not the same glider, but looks like the same model:
>
> https://farm8.staticflickr.com/7261/7545310106_818173ceca_b.jpg

--
Dan, 5J

[[email protected]]

Sounds like a good idea.

As an aside, I have many chute only landings in an Elfe S-3 and a Libelle 301. Besides being great pattern & speed control practice (I slip around the pattern from downwind through final until I'm at about 50ft before deploying the chute) its a hell of a lot of fun!

On Thursday, February 4, 2016 at 3:32:51 AM UTC-5, Surge wrote:
> One wonders if the inclusion of a tail parachute would have been a better option on these slippery open class ships with tricky recovery envelopes?
> Accidental or unreliable deployment issues aside, a drag chute could probably be used to recover from a spin or spiral dive without exceeding Vne.
>
> For example the Nimbus 2 has a terminal velocity in a vertical dive of 200 to 220 km/h (108 to 119 knots) with the tail chute deployed, air brakes and landing gear extended. So assuming one popped the chute within a couple of seconds (giving extra time to extend air brakes and lower the landing gear) the glider would be able to exit the spin/spiral vertically and then gently pull out of the dive without breaking anything in the process.
>
> Is this a crazy idea or feasible?

[Don Johnstone[_4_]]

At 16:12 04 February 2016, Dan Marotta wrote:
>How does that work? Do you push the knob forward to the detent to
>deploy the chute and then outboard and forward again to jettison?
What
>type of glider is that?
>
Looks like a Janus. If you are clumsy it is very easy to past the first
detent and all the way forward. The parachute then falls off in it's
container and is very difficult to find :-)

[Bruce Hoult]

On Friday, February 5, 2016 at 3:30:06 AM UTC+3, Don Johnstone wrote:
> At 16:12 04 February 2016, Dan Marotta wrote:
> >How does that work? Do you push the knob forward to the detent to
> >deploy the chute and then outboard and forward again to jettison?
> What
> >type of glider is that?
> >
> Looks like a Janus. If you are clumsy it is very easy to past the first
> detent and all the way forward. The parachute then falls off in it's
> container and is very difficult to find :-)

Yup, original Janus. Aerotow on belly hook, all-moving tailplane.

I never used the chute. The airbrakes themselves aren't so great, but add in landing flap and it's as good or better than a Grob. Plus it does a wicked sideslip which, unlike the parachute, is adjustable and can be recovered from and then applied again later as required.

[son_of_flubber]

On Thursday, February 4, 2016 at 11:02:14 AM UTC-5, Bruce Hoult wrote:
> On Thursday, February 4, 2016 at 6:32:26 PM UTC+3, son_of_flubber wrote:
> > On Thursday, February 4, 2016 at 3:32:51 AM UTC-5, Surge wrote:
> > > One wonders if the inclusion of a tail parachute would have been a better option on these slippery open class ships with tricky recovery envelopes?
> >
> > You would need a reliable means to jettison the chute at the right moment.
>
> Like the blue knob low on the right hand cockpit wall in my glider here, you mean?
>
> http://hoult.org/bruce/gliding/sasha/sasha-Images/3.jpg.
>
> First stop deploys the chute. Zig right and all the way forward to jettison it.

I was aware of the chute used for landing on Libelle. So you think a similar chute mechanism could be used during spin/spiral dive recovery.

[[email protected]]

Standard equipment for flight testing of aircraft:

http://www.airborne-sys.com/pages/view/aircraft-spin-stall-recovery-systems

On Thursday, February 4, 2016 at 6:51:48 PM UTC-8, son_of_flubber wrote:
> I was aware of the chute used for landing on Libelle. So you think a similar chute mechanism could be used during spin/spiral dive recovery.

[JS]

On Thursday, February 4, 2016 at 6:51:48 PM UTC-8, son_of_flubber wrote:
> On Thursday, February 4, 2016 at 11:02:14 AM UTC-5, Bruce Hoult wrote:
> > On Thursday, February 4, 2016 at 6:32:26 PM UTC+3, son_of_flubber wrote:
> > > On Thursday, February 4, 2016 at 3:32:51 AM UTC-5, Surge wrote:
> > > > One wonders if the inclusion of a tail parachute would have been a better option on these slippery open class ships with tricky recovery envelopes?
> > >
> > > You would need a reliable means to jettison the chute at the right moment.
> >
> > Like the blue knob low on the right hand cockpit wall in my glider here, you mean?
> >
> > http://hoult.org/bruce/gliding/sasha/sasha-Images/3.jpg.
> >
> > First stop deploys the chute. Zig right and all the way forward to jettison it.
>
> I was aware of the chute used for landing on Libelle. So you think a similar chute mechanism could be used during spin/spiral dive recovery.

Shouldn't this move to another thread?
Jim

[Mike Schumann[_2_]]

On Thursday, February 4, 2016 at 3:32:51 AM UTC-5, Surge wrote:
> One wonders if the inclusion of a tail parachute would have been a better option on these slippery open class ships with tricky recovery envelopes?
> Accidental or unreliable deployment issues aside, a drag chute could probably be used to recover from a spin or spiral dive without exceeding Vne.
>
> For example the Nimbus 2 has a terminal velocity in a vertical dive of 200 to 220 km/h (108 to 119 knots) with the tail chute deployed, air brakes and landing gear extended. So assuming one popped the chute within a couple of seconds (giving extra time to extend air brakes and lower the landing gear) the glider would be able to exit the spin/spiral vertically and then gently pull out of the dive without breaking anything in the process.
>
> Is this a crazy idea or feasible?

Another option that would cover a broader range of potential disasters is the installation of a ballistic recovery chute.

[JS]

Hallo Bert "TW"
Through a convoluted series of links, I stumbled into and read a very good article on "How To Survive Gliding" which at the end credits you.
Wielen danke.
Jim

http://www.tango-whisky.com/How%20to%20Survive%20Gliding.pdf


On Wednesday, February 3, 2016 at 5:51:16 AM UTC-8, Tango Whisky wrote:
> Le mercredi 3 février 2016 13:15:10 UTC+1, Justin Craig a écrit*:
> > Don,
> >
> > the answer is simple. Don't fly a Nimbus 4 if you do not feel competent to
> > do so.
>
> Justin,
>
> "feeling competent to" is probably he cause of death #1 amongst glider pilots.
>
> I absolutely agree with you that if one doesn't feel competent to fly an open glass glider, then he shouldn't. But "feeling compentent" might be a different thing than "being competent".
> I'm not addressing that to any person in specific. However, having spin experience in a ASK21 or a Discus does not mean that you will survive a fully developed spin in an open glass ship. The momentum of the wing is about 3-5 times larger than that of a 15m glider, and when you do the right inputs to stop the spin, the large momentum means that until the actual rotation is stopped, you are accelerating nose down by 70-80 deg with negative flaps for almost a full turn. So if you wait for the rotation to have stopped before you pull up, there is almost no way that the wings would stay with you.. If you don't wait long enough, you might re-stall the wing. The margin for a successful exit is very slim, while on a 15 m ship it is absolutely easy.
>
> Been there, done that long ago on a 26 m ship, happy to be still alive. After that event, any incipent stall on a ASH25 got my immediate attention.

[[email protected]]

On Thursday, February 4, 2016 at 3:32:51 AM UTC-5, Surge wrote:
> One wonders if the inclusion of a tail parachute would have been a better option on these slippery open class ships with tricky recovery envelopes?
> Accidental or unreliable deployment issues aside, a drag chute could probably be used to recover from a spin or spiral dive without exceeding Vne.
>
> For example the Nimbus 2 has a terminal velocity in a vertical dive of 200 to 220 km/h (108 to 119 knots) with the tail chute deployed, air brakes and landing gear extended. So assuming one popped the chute within a couple of seconds (giving extra time to extend air brakes and lower the landing gear) the glider would be able to exit the spin/spiral vertically and then gently pull out of the dive without breaking anything in the process.
>
> Is this a crazy idea or feasible?

With the sailplane departing form controlled flight and then accelerating at a high rate I wonder if the pilot would remember to actuate the chute. The critical part happens very quickly and is disorienting. Some would want to try to save it to avoid having to lose the chute.
That said it might be very useful after the wings are pulled off by making the projectile more stable and buying exit time.
FWIW
UH

[BobW]

On 2/6/2016 6:50 PM, JS wrote:
> Hallo Bert "TW" Through a convoluted series of links, I stumbled into and
> read a very good article on "How To Survive Gliding" which at the end
> credits you. Wielen danke. Jim
>
> http://www.tango-whisky.com/How%20to%20Survive%20Gliding.pdf

Excellent, thoughtful, thought-provoking link!!! I thought what it touches
upon worthy of its own thread...

As to the article's ending point, here's a public, recent, "There I Wuz..."
soaring-centric article to see if it's possible on RAS to help jump-start such
a discussion.

http://www.flyingmag.com/i-learned-about-flying-from-that-land-out-at-kitt-peak

The experienced glider pilot in me cringed upon reading the Flying magazine
article...but long exposure and participation in recreational soaring had also
long ago led to my concluding the "mental mindset errors" displayed by the
pilot in the Flying magazine article are (excuse the pun) dirt common. *Why*
they are has also long been a real puzzler for me: Lack of exposure? Denial?
("e.g. Only a ignorant idiot would do that - not me!" mindset.) Risk-raising
mental compartmentalization? ???

What do others think?

Bob W.

[[email protected]]

It would be interesting to know if the root cause is the same. If there are a loss of control, and the root cause is unintended opening of airbrakes in flight.

In France there have been a series of incidents with unintended opening of airbrakes at speeds above 130 km/h.

http://www.volavoile.net/index.php?showtopic=10981

Peter


Den søndag den 31. januar 2016 kl. 11.48.10 UTC+1 skrev :
> In Denmark we had a serious incident regarding an Arcus.
>
> The left wing airbrake bell crank ruptured as a consequence of inadequate weld quality. The strength of the welds was insufficient to withstand airbrake bell crank operational loads. The bell crank broke as the glider was in 600ft and had a speed of 108t. The left airbrake extended, The pilot made a brilliant recovery extending the right airbrake and landed the glider 32 seconds later.
>
> You find the full report http://www.hcl.dk/index.php?option=com_contentbuilder&title=søg-luftfart-hclj530-2015-45-bulletin&controller=details&id=3&record_id=426&Itemid=161&limitstart=0&filter_order=&lang=da
>
> -Peter