A aviation & planes forum. AviationBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » AviationBanter forum » rec.aviation newsgroups » Soaring
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

Service Ceiling L23 - Litigation



 
 
Thread Tools Display Modes
  #1  
Old December 17th 20, 04:06 AM posted to rec.aviation.soaring
[email protected]
external usenet poster
 
Posts: 61
Default Service Ceiling L23 - Litigation

After reading the article I retrieved my copy of the L23 flight manual. Where does it say you can't fly it higher than 12,805 feet? There are VNE reductions calculated up to 35,000, but nowhere in it can I find a service ceiling limitation as the plaintiff seems to suggest there are.

Did I miss something?

Note:I am aware of the differences between flight test for certification and the extrapolation used to prepare the manual.


https://trib.com/news/state-and-regi...249be5d1c.html
Ads
  #2  
Old December 17th 20, 07:11 AM posted to rec.aviation.soaring
Haven
external usenet poster
 
Posts: 10
Default Service Ceiling L23 - Litigation

I didn't see any discussion of service ceiling. Back ~'98 I had a great ride in a two-place Grob 103 at Driggs, where we made a couple of circuits around the Grand Teton waving at the mountain climbers. Can't remember how high we were upon release or much more detail of the flight. The G103 and L23 have similar performance figures but it is all dependent on the skill and judgment of the pilot. Absent evidence of structural or flight controls/surfaces failure we are left with pilot error as the cause of the accident.

On Wednesday, December 16, 2020 at 7:06:26 PM UTC-8, wrote:
After reading the article I retrieved my copy of the L23 flight manual. Where does it say you can't fly it higher than 12,805 feet? There are VNE reductions calculated up to 35,000, but nowhere in it can I find a service ceiling limitation as the plaintiff seems to suggest there are.

Did I miss something?

Note:I am aware of the differences between flight test for certification and the extrapolation used to prepare the manual.


https://trib.com/news/state-and-regi...249be5d1c.html

  #3  
Old December 17th 20, 05:14 PM posted to rec.aviation.soaring
[email protected]
external usenet poster
 
Posts: 12
Default Service Ceiling L23 - Litigation

On Thursday, December 17, 2020 at 1:11:08 AM UTC-5, Haven wrote:
I didn't see any discussion of service ceiling. Back ~'98 I had a great ride in a two-place Grob 103 at Driggs, where we made a couple of circuits around the Grand Teton waving at the mountain climbers. Can't remember how high we were upon release or much more detail of the flight. The G103 and L23 have similar performance figures but it is all dependent on the skill and judgment of the pilot. Absent evidence of structural or flight controls/surfaces failure we are left with pilot error as the cause of the accident.
On Wednesday, December 16, 2020 at 7:06:26 PM UTC-8, wrote:
After reading the article I retrieved my copy of the L23 flight manual. Where does it say you can't fly it higher than 12,805 feet? There are VNE reductions calculated up to 35,000, but nowhere in it can I find a service ceiling limitation as the plaintiff seems to suggest there are.

Did I miss something?

Note:I am aware of the differences between flight test for certification and the extrapolation used to prepare the manual.


https://trib.com/news/state-and-regi...249be5d1c.html



Maybe they didn't have oxygen on that flight?
RO
  #4  
Old December 18th 20, 12:12 AM posted to rec.aviation.soaring
Frank Whiteley
external usenet poster
 
Posts: 2,099
Default Service Ceiling L23 - Litigation

On Wednesday, December 16, 2020 at 8:06:26 PM UTC-7, shaun_xxxxxxxxxxx wrote:
After reading the article I retrieved my copy of the L23 flight manual. Where does it say you can't fly it higher than 12,805 feet? There are VNE reductions calculated up to 35,000, but nowhere in it can I find a service ceiling limitation as the plaintiff seems to suggest there are.

Did I miss something?

Note:I am aware of the differences between flight test for certification and the extrapolation used to prepare the manual.


https://trib.com/news/state-and-regi...249be5d1c.html

Shawn there are a number of L-23 Pilot Manuals PDF'd on the web. There are page revisions to most, but the PDFs may be dated. Ours was N392BA and appears on a few sites. It was sold and exported to Argentina several years ago. That page has the limit in one or more version, yet it's missing from others. So there may have been page changes made to the Pilot Manual and applied inconsistently.
The manual lists the 'demonstrated' ceiling in para 2.11, but it's manual page revision number is 1012.3 and is listed as S/N 978307, no N-number. It appears to apply to serial numbers 938101 and subsequent.
http://www.cagcsoaring.ca/wp-content...per-Blanik.pdf
It's in this copy
http://www.soarccsc.com/wp-content/u...ght-Manual.pdf

It does not appear in manual version/revision 1014.5 for serial numbers 029005 and subsequent.

So, it's a tough question. There were some payload changes from some of the earlier serial number. The first two digits are year of manufacture. Were there pilot manual page inserts that updated the pilot manual? I don't think demonstrated service altitude is a service limit.

FAA TCDS info for G60EU_Rev8
https://rgl.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/0/4be37cc5c028c09f86258115005f3e32/$FILE/G60EU_Rev_8.pdf

No pilot manual mentions an altitude placard. I certainly soared ours up to 17,500 several times.

The accident docket is here https://data.ntsb.gov/Docket?ProjectID=97436

Frank Whiteley
  #5  
Old December 18th 20, 01:45 AM posted to rec.aviation.soaring
2G
external usenet poster
 
Posts: 1,439
Default Service Ceiling L23 - Litigation

On Thursday, December 17, 2020 at 3:12:22 PM UTC-8, Frank Whiteley wrote:
On Wednesday, December 16, 2020 at 8:06:26 PM UTC-7, shaun_xxxxxxxxxxx wrote:
After reading the article I retrieved my copy of the L23 flight manual. Where does it say you can't fly it higher than 12,805 feet? There are VNE reductions calculated up to 35,000, but nowhere in it can I find a service ceiling limitation as the plaintiff seems to suggest there are.

Did I miss something?

Note:I am aware of the differences between flight test for certification and the extrapolation used to prepare the manual.


https://trib.com/news/state-and-regi...249be5d1c.html

Shawn there are a number of L-23 Pilot Manuals PDF'd on the web. There are page revisions to most, but the PDFs may be dated. Ours was N392BA and appears on a few sites. It was sold and exported to Argentina several years ago. That page has the limit in one or more version, yet it's missing from others. So there may have been page changes made to the Pilot Manual and applied inconsistently.
The manual lists the 'demonstrated' ceiling in para 2.11, but it's manual page revision number is 1012.3 and is listed as S/N 978307, no N-number. It appears to apply to serial numbers 938101 and subsequent.
http://www.cagcsoaring.ca/wp-content...per-Blanik.pdf
It's in this copy
http://www.soarccsc.com/wp-content/u...ght-Manual.pdf

It does not appear in manual version/revision 1014.5 for serial numbers 029005 and subsequent.

So, it's a tough question. There were some payload changes from some of the earlier serial number. The first two digits are year of manufacture. Were there pilot manual page inserts that updated the pilot manual? I don't think demonstrated service altitude is a service limit.

FAA TCDS info for G60EU_Rev8
https://rgl.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/0/4be37cc5c028c09f86258115005f3e32/$FILE/G60EU_Rev_8.pdf

No pilot manual mentions an altitude placard. I certainly soared ours up to 17,500 several times.

The accident docket is here https://data.ntsb.gov/Docket?ProjectID=97436

Frank Whiteley


The point in the complaint “being towed and released at an altitude that exceeded the certification and rating of the glider” is specious and not supported in the POH. The accident docket, however, contains several disturbing examples of poor pilotage. The pilot was flying very uncoordinated at low airspeeds close to the terrain. Additionally, there were indications of strong gusting winds at the time of the accident and the glider encountered strong sink multiple times shortly before the accident. Twice the pilot said "this is not good" prior to the accident as recorded by the passenger's smartphone, indicating she did not have situational awareness. The accident photo showed a vertical impact, so the pilot likely entered a stall/spin. This accident was totally preventable by maintaining some extra airspeed and flying coordinated. It is interesting that the docket includes a Soaring article on mountain flying by Henry Combs in 1984, which gives me a strong indication of where the investigation is heading.

Tom
  #6  
Old December 18th 20, 05:03 AM posted to rec.aviation.soaring
[email protected]
external usenet poster
 
Posts: 61
Default Service Ceiling L23 - Litigation

Thank you for the responses.

I could not find anything to support counsel's mendacious claim that the aicraft was towed or flown above any restriction either by the manufacturer or by the FAA. The evidence seems to support your opinion, Tom, that she got into sink and did not correct accordingly. Why was she so far out of trim? 45 degrees in the front seat isn't something you wouldn't notice from the back.



  #7  
Old December 18th 20, 04:48 PM posted to rec.aviation.soaring
Stuart Venters
external usenet poster
 
Posts: 6
Default Service Ceiling L23 - Litigation

On 12/17/20 10:03 PM, wrote:
Thank you for the responses.

I could not find anything to support counsel's mendacious claim that the aicraft was towed or flown above any restriction either by the manufacturer or by the FAA. The evidence seems to support your opinion, Tom, that she got into sink and did not correct accordingly. Why was she so far out of trim? 45 degrees in the front seat isn't something you wouldn't notice from the back.



There is a mention of 12-5 in the accident report interviews.

https://data.ntsb.gov/Docket/Documen...%20-Master.PDF

Page 104 line 3 regarding the length or glider flights.

3 A. It would be to be 2 hours. But that being said, even if it
4 is, we're never above 12-5 for more than 30 minutes due to the
5 oxygen requirements. So we have that kind of ceiling.
  #8  
Old December 19th 20, 11:08 PM posted to rec.aviation.soaring
2G
external usenet poster
 
Posts: 1,439
Default Service Ceiling L23 - Litigation

On Thursday, December 17, 2020 at 8:03:51 PM UTC-8, wrote:
Thank you for the responses.

I could not find anything to support counsel's mendacious claim that the aicraft was towed or flown above any restriction either by the manufacturer or by the FAA. The evidence seems to support your opinion, Tom, that she got into sink and did not correct accordingly. Why was she so far out of trim? 45 degrees in the front seat isn't something you wouldn't notice from the back.


By "trim" I assume that you mean rudder coordination and not nose-down trim.. I assume that there is a yaw string for the back seat as the front yaw string would not be visible to the pilot. She was both allowing airspeed to bleed off to dangerously slow levels and not monitoring control coordination.. It is puzzling why, after twice saying "This is not good" that she didn't turn back to the airport.

The lawyer is probably not a pilot and may have interpreted the O2 altitude limitation to be an airframe limitation. He has plenty of malfeasances to hold Teton Aviation's feet to the fire, however.

Tom
  #9  
Old December 20th 20, 12:01 AM posted to rec.aviation.soaring
Tango Eight
external usenet poster
 
Posts: 962
Default Service Ceiling L23 - Litigation

On Saturday, December 19, 2020 at 5:09:01 PM UTC-5, 2G wrote:
On Thursday, December 17, 2020 at 8:03:51 PM UTC-8, wrote:
Thank you for the responses.

I could not find anything to support counsel's mendacious claim that the aicraft was towed or flown above any restriction either by the manufacturer or by the FAA. The evidence seems to support your opinion, Tom, that she got into sink and did not correct accordingly. Why was she so far out of trim? 45 degrees in the front seat isn't something you wouldn't notice from the back.

By "trim" I assume that you mean rudder coordination and not nose-down trim. I assume that there is a yaw string for the back seat as the front yaw string would not be visible to the pilot. She was both allowing airspeed to bleed off to dangerously slow levels and not monitoring control coordination. It is puzzling why, after twice saying "This is not good" that she didn't turn back to the airport.

The lawyer is probably not a pilot and may have interpreted the O2 altitude limitation to be an airframe limitation. He has plenty of malfeasances to hold Teton Aviation's feet to the fire, however.

Tom



Look through the photos in item 30 on the docket linked earlier in the thread (still frames from video the passenger was recording in the moments before the crash), it's very strange. Ridge on the left, very close aboard (less than 100 feet is my guess), left bank about 30 degrees, yaw string indicating what appears to be full right rudder. The full video would probably provide additional insight. The last two frames, 9 seconds apart, don't show evidence of a rapid descent... comparing the two views with the ridge line and considering the severe uncoordinated flight condition, I would guess the glider is flying in lift.

More questions than answers.

T8
  #10  
Old December 20th 20, 07:43 AM posted to rec.aviation.soaring
[email protected]
external usenet poster
 
Posts: 61
Default Service Ceiling L23 - Litigation

Grand Teton is 13,776 ft. Icefloe Lake is 10,652 ft. If the first frame began at release altitude then they were slightly below and to the south of the summit of Grand Teton. In 3:09 they lost 3100 feet give or take.


https://www.youtube.com/watch?v=lvWNkP-NzAQ



 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Max Service ceiling for commercial airplanes [email protected] Piloting 64 January 31st 08 10:03 AM
Camera Litigation in UK [email protected] Soaring 12 January 28th 06 08:16 PM
A Service ceiling question (Piper 235) falcon Owning 0 December 6th 04 11:28 PM
A Service ceiling question (Piper 235) falcon Piloting 0 December 6th 04 11:28 PM
service ceiling of F-22 zxcv Military Aviation 7 March 14th 04 11:31 PM


All times are GMT +1. The time now is 09:59 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.
Copyright 2004-2021 AviationBanter.
The comments are property of their posters.