Glider accident while filming commercial in 2011. NTSB Report updated

On 22/06/2013 15:01, Bill D wrote:
On Saturday, June 22, 2013 1:41:41 AM UTC-6, Alan wrote:
In article Bill D

writes:



I'm positive that if it's done right, winch launch is far safer than aero t=

ow. Germans suffer one accident on average every 180,000 winch launches wh=

ile we suffer one every 24,000 aero tows. I know there are cultural differ=

ences but, presumably, we're pretty good at aero tow and they're at least a=

s good at winch launch so the comparison is probably valid.



But, what is the severity of these accidents?

The severity is exactly the same for both aero tow and winch. The German LBU accident statistics are

available on-line just as the NTSB data is. I suggest you verify them
yourself.

I have no idea where the SSF got their numbers but it may have been the UK since no translations

are required. 2011 data shows the UK suffers one accident every 16,000
launches while

Germany suffers one every 180,000. German numbers are roughly
comparable to the rest of continental

Europe. The SSF needs to take another, wider look.

Bill makes the classic mistake of the amateur statistician - failing to
understand the different definitions & methods behind the statistics he
quotes.

None of the statistics Bill quotes can be relied upon to be an accurate
comparison.

Ed.

On Saturday, June 22, 2013 5:50:18 PM UTC-6, Chris Nicholas wrote:
Bill, I entirely agree that it is not the only factor - we have

identified 6 factors as the most notable circumstances, of which

belly hooks are one. It is a fact that the first such UK fatality was

with a belly hook (and also turbulence, and probably

recency/currency, were others in that case).



Dan’s point AIUI was you only have to fly the glider. My main point

was too many people didn’t, and over here at least are starting not

to again. Another of my points is that by education and supervision,

we are trying to address the re-emergence of the issue.



Our policy is that you should not have more than two, if that, of the

factors present on any one launch. Had that been known, adopted

and followed, the first such fatality would probably not have

happened.



By the way, another factor not in the list of 6 is distraction, which

has emerged recently in incident reports.



Regards - Chris

Maybe this will help.

https://dl.dropboxusercontent.com/u/...ng%20Guide.pdf

Aero tow is just not an inherently safe procedure and pilots need to understand that. Of course, winch launch isn't inherently safe either but at least they don't kill a tow pilot.

On Saturday, June 22, 2013 6:01:54 PM UTC-6, B4soaring wrote:
On 22/06/2013 15:01, Bill D wrote:

On Saturday, June 22, 2013 1:41:41 AM UTC-6, Alan wrote:

In article Bill D



writes:







I'm positive that if it's done right, winch launch is far safer than aero t=



ow. Germans suffer one accident on average every 180,000 winch launches wh=



ile we suffer one every 24,000 aero tows. I know there are cultural differ=



ences but, presumably, we're pretty good at aero tow and they're at least a=



s good at winch launch so the comparison is probably valid.







But, what is the severity of these accidents?



The severity is exactly the same for both aero tow and winch. The German LBU accident statistics are



available on-line just as the NTSB data is. I suggest you verify them

yourself.



I have no idea where the SSF got their numbers but it may have been the UK since no translations



are required. 2011 data shows the UK suffers one accident every 16,000

launches while



Germany suffers one every 180,000. German numbers are roughly

comparable to the rest of continental



Europe. The SSF needs to take another, wider look.



Bill makes the classic mistake of the amateur statistician - failing to

understand the different definitions & methods behind the statistics he

quotes.



None of the statistics Bill quotes can be relied upon to be an accurate

comparison.



Ed.

Bull ****! I've spend years investigating these reports and vetting the analysis with experts. These are not statistics or summaries, they are actual numbers obtained from the respective national aviation safety boards who use the same investigative techniques. They are 100% reliable for comparisons.

There is no way to overcome an order of magnitude difference no matter how you spin the numbers. If you don't believe it, try to make the numbers come out the other way.

On Sat, 22 Jun 2013 15:44:22 -0700 (PDT), Bill D
wrote:
[snip]


something no sane person would approve as an air-show act."

To dramatize that simile, here's an air show act that didn't come off
well today...

http://www.10tv.com/content/stories/...how-crash.html

. . .

Bill makes the classic mistake of the amateur statistician - failing to

understand the different definitions & methods behind the statistics he

quotes.



None of the statistics Bill quotes can be relied upon to be an accurate

comparison.



Ed.

Bull ****! I've spend years investigating these reports and vetting the analysis with experts. These are not statistics or summaries,

they are actual numbers obtained from the respective national aviation
safety boards who use the same investigative techniques. They

are 100% reliable for comparisons.

There is no way to overcome an order of magnitude difference no matter how you spin the numbers. If you don't believe it, try to make

the numbers come out the other way.



"they are actual numbers obtained from the respective national aviation
safety boards who use the same investigative techniques"

No, they are not. The equivalent of the BFU is the AAIB - if you wish to
make comparisons you should compare the BFU statistics with the AAIB
figures.

Ed.

ps an earlier post of yours refers to the "German LBU"; I'm aware of the
LBA, I know of the BFU but your reference to the "German LBU" is puzzling.

No, they are not. The equivalent of the BFU is the AAIB - if you wish to make comparisons you should compare the BFU statistics with the AAIB figures.
_____________________

What!!? The AAIB doesn't publish glider accident statistics - they leave that to the BGA. I used the BGA numbers for 2011.

ps an earlier post of yours refers to the "German LBU"; I'm aware of the LBA, I know of the BFU but your reference to the "German LBU" is puzzling.

The German LBA is their FAA equivalent. The BFU is the NTSB/AAIB equivalent. The "LBU" was a typo.

The numbers I used are available for anybody to read and analyze. The differences are so huge, there's no way to come up with a different result. If you disagree, go read them and do your own analysis.

On 06/20/2013 09:53 PM, Steve Leonard wrote:

http://www.ntsb.gov/aviationquery/br...FA010 &akey=1

Happened to be looking through the NTSB Database and saw that they updated the report about a month ago.


Firstly let me express my condolences to the friends and family of the
late pilot. There has been a lot of noise on this thread about this
accident. But adding to the above with the additional documents and
video published he

http://dms.ntsb.gov/pubdms/search/hi...KEN=7351 7888

I would like to post this in the spirit of learning from past mistakes.
I think this is what probably happened:

- The length of the tow rope was much shorter than the typical minimum
length of 300m used for a conventional auto tow launches. The runway was
also shorter than that which would normally be considered suitable for
auto tow. Thus this operation should be regarded as a stunt contrived
for the benefit of the camera's rather than a conventional soaring launch.

- The video shows the glider being towed horizontally behind the tow
vehicle and then performing a "kite" manoeuvre where the glider pitches
nose up, gains altitude rapidly and accelerates due to the geometry of
changing the relative direction. Intentional "kite" manoeuvres are
conducted in a controlled manner during a conventional ground launch.
They can also occur unintentionally during aerotow where they can cause
tug upset accidents. It is not clear if the kite manoeuvre on the crash
flight was initiated deliberately by the pilot for the purposes of the
camera, or if it happened accidentally.

- In the accident flight the kite manoeuvre caused the rope to break.
The pilot then lowered the nose to return to a normal gliding attitude.
(Even if the rope did not break, the short length of the rope would have
required the manoeuvre to end within a few seconds, eg by a back
release, the pilot releasing or the pilot lowering the nose.)

- As the launch was conducted outside of the parameters of a normal auto
tow, there may have been insufficient runway length available to land
ahead - the conventional recovery procedure for a ground launch failure
at this hight. The tow vehicle also presented an obstacle to landing
ahead, another aspect which differs from a conventional auto tow launch.

- Rather the pilot attempted a 180 degree turn to land downwind on the
runway again, similar to the recovery manoeuvre from an aerotow rope
failure at that altitude. However the pilot lost control, stalled and/or
spun and crashed.

- It is standard procedure when recovering from a ground launch rope
failure to lower the nose and the WAIT UNTIL AIRSPEED RECOVERS BEFORE
TURNING OR USING AIRBRAKES. As the glider experiences lowered or
negative G during the "push over" manoeuvre used to lower the nose after
the cable brake, it can fly normally even if the airspeed drops below
the nominal stalling speed. However after the push over is completed,
the glider experiences 1G and requires airspeed above nominal stall
speed to fly. This may be achieved only after some seconds after the
nose has been lowered. Any attempt to manoeuvre the glider during this
period can easily lead to loss of control. This is clearly illustrated
in this BGA training material:

http://www.gliding.co.uk/bgainfo/saf...deo/spin-4.mp4

- I suspect the pilot had insufficient airspeed when he attempted the
180 degree turn.

The pilots options in this situation were compromised due to the non
compliance with the norms for an autotow launch. It is not clear whether
he had sufficient altitude, speed and runway space to complete a safe
landing.

I hope that readers will appreciate that ground launching can be
conducted safely, provided that it is conducted within established
norms. Pilots should have appropriate training and ground launch
operations should be conducted under the supervision of skilled and
current ground launch instructors. However deviating these norms can
rapidly increase the potential hazards.


Ian

At 02:32 23 June 2013, Bill D wrote:

No, they are not. The equivalent of the BFU is the AAIB - if you wish
to
make comparisons you should compare the BFU statistics with the AAIB
figures.
_____________________

What!!? The AAIB doesn't publish glider accident statistics - they leave
that to the BGA. I used the BGA numbers for 2011.

ps an earlier post of yours refers to the "German LBU"; I'm aware of the

LBA, I know of the BFU but your reference to the "German LBU" is
puzzling.

The German LBA is their FAA equivalent. The BFU is the NTSB/AAIB
equivalent. The "LBU" was a typo.

The numbers I used are available for anybody to read and analyze. The
differences are so huge, there's no way to come up with a different
result.
If you disagree, go read them and do your own analysis.

Sorry Bill but your statistics are seriously flawed, In the UK the Air
Cadet organisation carry out nearly 50% of the total winch launches in the
UK in any year. The Air Cadets have not had a fatal or serious injury from
a failed winch launch accident since 1963 and probably before that.
The accidents/incidents reported by the BGA far exceed what would normally
be recorded by a national government source.
You will see that minor crime has decreased in the UK over the years if you
look at statistics. What the statistics do not tell you is that people have
stopped reporting minor crime so of course it has reduced. Same thing
applies to AAIB statistics, they do not record all the minor stuff that the
BGA do.

Le vendredi 21 juin 2013 07:30:21 UTC+2, a écrit*:
Le jeudi 20 juin 2013 21:53:31 UTC+2, Steve Leonard a écrit*:

It looks like they tried to more or less duplicate an old commercial by Michelin, where you saw an ASK-21 being auto-towed on a frozen lake. The glider went brutally up on a very short rope and released almost immediately. Then the car came to a braking halt just in front of an obstacle, while the glider was flying away. It was to illustrate the grip of a "Drice" winter tire... I can't find it on the web anymore. Some small stills are visible if you google "Michelin Drice" for images, but the links are dead.

I put a copy of the Michelin ad on YouTube, for comparison purpose: http://youtu.be/Rcc2yKQFW5Q

On Sunday, June 23, 2013 3:35:00 AM UTC-6, Don Johnstone wrote:
At 02:32 23 June 2013, Bill D wrote:



No, they are not. The equivalent of the BFU is the AAIB - if you wish

to

make comparisons you should compare the BFU statistics with the AAIB

figures.

_____________________



What!!? The AAIB doesn't publish glider accident statistics - they leave

that to the BGA. I used the BGA numbers for 2011.



ps an earlier post of yours refers to the "German LBU"; I'm aware of the



LBA, I know of the BFU but your reference to the "German LBU" is

puzzling.



The German LBA is their FAA equivalent. The BFU is the NTSB/AAIB

equivalent. The "LBU" was a typo.



The numbers I used are available for anybody to read and analyze. The

differences are so huge, there's no way to come up with a different

result.

If you disagree, go read them and do your own analysis.



Sorry Bill but your statistics are seriously flawed, In the UK the Air

Cadet organisation carry out nearly 50% of the total winch launches in the

UK in any year. The Air Cadets have not had a fatal or serious injury from

a failed winch launch accident since 1963 and probably before that.

The accidents/incidents reported by the BGA far exceed what would normally

be recorded by a national government source.

You will see that minor crime has decreased in the UK over the years if you

look at statistics. What the statistics do not tell you is that people have

stopped reporting minor crime so of course it has reduced. Same thing

applies to AAIB statistics, they do not record all the minor stuff that the

BGA do.


Don, I used only the BGA numbers. I did not use any AAIB numbers since none are available. I stand by my results until the BGA supplies different numbers. Note carefully that I used the most favorable interpretation for the UK and digging deeper will most likely make things look worse.

For example, the BGA numbers reported were obviously restricted to fatal or serious injury accidents whereas the German BFU and the NTSB reported all of them so the real situation is actually worse for the UK than it appears. I have numbers supporting that contention but I chose not to publish them..

Even giving the UK the benefit of the doubt, the results say the Germans are more than 10 times safer than the Brits on winch launch and the Germans are 7 - 8 times safer on winch launch than US is with aero tow. Play with the numbers if you want, but it's very, very doubtful you can overcome or explain away differences that big.

The solution is fixing the safety problem, not attacking the numbers. I'd start by finding out what the Germans are doing right.