Glider accident while filming commercial in 2011. NTSB Report updated

Ian, excellent analysis. I agree.

It was a stunt which brings up the relationship with the video crew.

Directors are known to push stunt people to produce ever more dramatic scenes trusting that, as professionals, they will push back if things get really dangerous. This pilot probably didn't push back and the video folks probably didn't realize he wasn't a professional so things got out of hand.

The real pro's would have gone out to a deserted strip or dry lake with lots of room to recover from mistakes and flown the scripted maneuver over and over approaching the dangerous parts in small steps until all the bugs were worked out before trying it in front of the cameras on a short strip. At the short strip, they would have all the "outs", like the farm field off the departure end, precisely determined and have resolved to use them if something went wrong. It's a hard business, not a game of "dare".

One of the many "take-homes" from this sad affair is never let anyone push you to do something your gut says is dangerous.





On Sunday, June 23, 2013 2:10:17 AM UTC-6, Ian wrote:
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