simulation of a fatality report

[Tad Eareckson]

2006/02/05
13:15

Accident Pilot:
Advanced
AT FL
RLF TUR X-C

Pacific Airwave Vision Pulse 10 Meter

Quest Air Soaring Center
Runway 27

aerotow
tug: Dragonfly 914
tow line: 250 feet
dolly launch

primary release: Quest
secondary release system: twin Baileys
weak links: 140 pound at top end of primary and both ends of secondary bridles

post frontal
winds: west - 10-12 mph

Accident Description

We are especially fortunate with respect to the analysis of this accident to have had numerous witnesses, a track log, and a high resolution digital movie camera set up on a tripod a hundred yards upwind from the launch point which recorded the entire sequence of events.

A highly experienced pilot whose airtime had been accumulated almost exclusively through aerotowing waited for a lull. Unbeknownst to the tug and glider pilots a huge thermal cycle had started blowing through about a minute prior downwind of the launch point whipping through the pines and sending people running for their gliders in the setup and staging areas.

Launch was commenced before the pilots could be alerted to the danger.

Although the roll and liftoff themselves were smooth and uneventful, at ten feet the glider began a hard roll to the right. With the glider continuing to climb and roll the pilot for several seconds attempted to correct but the effort was rewarded with limited success.

Scenario 1

At this point the control effort was interrupted in favor of a reach for the release actuator - a bicycle brake lever assembly on the starboard downtube. Unfortunately it was insecurely mounted (velcro) and rotated 90 degrees outboard without effect.

The pilot immediately transferred his hand to the starboard barrel release but the force was such by that point that it was overloaded and inoperable.

After approximately two seconds the pilot made a second effort with respect to the primary release. By grasping the downtube and squeezing the lever he achieved success.

However, by this point - at a hundred feet - the glider had rolled to 80 degrees and fully locked out and the situation was not recoverable. The pilot stuffed the bar and dove to the ground downwind at a steep angle. An effort to flare made at the last instant was totally ineffectual.

The pilot died instantly from massive upper body trauma.

Scenario 2

The pilot then actuated the primary release by means of a basetube mounted brake lever but the bridle wrapped before clearing the tow ring (carabiner).

Following a short hesitation the pilot grasped the starboard Bailey but the glider was now steeply banked and the force was such that the release was severely overloaded and inoperable.

The glider continued to roll to 90 degrees until the port secondary weak link failed but by this point it was fully locked out and dove to the ground downwind at a steep angle.

The pilot died instantly from massive upper body trauma.

Scenario 3

The pilot then actuated the primary release by means of a basetube mounted brake lever but the cable adjustment was slightly off and the lever bottomed out on the basetube without effect.

Following a short hesitation the pilot grasped the starboard Bailey. An initial effort failed but a second later success was achieved with a vigorous pull and the bottom end of the primary bridle was freed.

Unfortunately, the bridle wrapped before clearing the tow ring (carabiner). As the trim point on the keel of that model glider is fairly far fore of the hang point it immediately pitched down and dove very steeply. The weak link failed twenty feet before the glider impacted the ground. It was immediately obvious to all witnesses that there was no possibility of survival.

The pilot died instantly from massive upper body trauma.

[Batman]

Scenario 4.

The hang glider pilot suddenly realizes that in front of him is a galloping pig as big as a car. At the same time, he noticedsa helicopter flying at ground level directly behind him. Both the giant pig and
the helicopter are traveling at the same speed as the pilot. Shrieking with fear (eek!) the hang glider pilot realizes he is clearly too drunk to fly and needss to get off the children's merry-go-round.

True story!
(no pigs or helicopters were hurt in the writing of this story)

[Paul Tjaden]

I have never allowed myself to get sucked into one of these threads but what the hell!!! Although I personally think that the bicycle brake release handle could be improved upon (perhaps by adding the wrist loop like Lookout uses) This idea that a barrel release will become functionally inoperative due to high loading is hog wash. The weak link or line that is attached to the barrel release is placed so far down on the cam lever that the idea that this could overload the release mechanism is absolute nonsense. I have used this type of release in lockout situations at altitude and the necessary force is negligible. Tad, I challenge you to create a strong enough pulling force using normal bridle materials that I (or someone even older and weaker) couldn't easily pull the barrel off of the cam and execute a normal release. If you can do this, I will switch to your release system. Put up.....or shut up!

Paul T.

[markc]

Hi Tad,

You are completely welcome to start a topic along the lines of, say, "Bailey releases in
lock-out scenarios" . And then engage in discussion about the merits of barrel releases.

But this one, which seems to combine real accident report information with a variety of
postulated scenarios of release difficulties, just isn't of any help. Heck, I can't even
remember which (if any) of those scenarios is the *real* one. And if I can't, then this
simply isn't going to be helpful to new pilots.

So I'm locking this thread down.

If a new one IS opened....

I'll warn all participants in advance: If the discussion veers into condescension,
sneering, veiled insults, or anything like I've seen in other threads, then it
will also be shut down. Or worse.

MarkC