Julia - flying a small glider
Pinned to the cart (Souther field)
Maybe it would've been smarter to tow from the other end of the field?Julia Kucherenko - 2011/05/16 12:35:57 UTC
Most people are convinced that the reason for my crash was coming off the cart too early. That is not quite right. I'll try to describe my guess at what happened:
1. Low angle of attack - glider got "stuck" to the cart
Angle of attack. We all know, that we should check it before we launch. So do I and I always put keel support in the lowest position possible. But my Combat 12 has a smaller airframe compare to other gliders and often even lowest position is not enough. I got used to it, and almost every second launch I had to "push out" basebar to get off the cart, when I feel that I am traveling with enough speed but the glider is still not flying. I thought this was normal.
2. Cross tail wind with combination of uneven ground - bouncy run.
There was cross-tail wind and uneven ground to make dolly roll faster and bounce, kicking my keel up. That's why I got the feeling of a glider flying "tail up". So at a certain point, when I felt enough speed and even saw the Dragonfly come off the ground in front of me I tried to push out. The basebar left the basebar cradle on the cart, but apparently my tail didn't leave its support. It got stuck in the cart keel support (I don't use a tail). For a second or two I kept flying straight, trying to push out without any success, and then suddenly felt a strong push down on my nose that smashed me into the ground.
3. Too much VG on
4. Tug prop downwash
I crashed right between two red cones, indicating where the tug stops when the rope is tight and then starts when the pilot is ready. Maybe I was in the prop downwash which nailed me down. Maybe I simply got a kick up to my keel that made a same effect. Keel tube had multiple dents and paint marks, which could indicate that at the moment of the crash my keel was still on the keel support on the cart.
Evidence:
1. Multiple paint scratches and dents on my keel tube.
2. Feeling that the "basebar was stuck to the cart."
3. Feeling that a glider is flying "tail up" and no matter how hard I'm pushing out - it didn't want to go higher. Even after I got rid of the cart at the base tube.
4. Strong nose down push in the end, while I was pushing out.
Glider has broken keel, front wires, LE, upright, ripped sail in several places - the impact was pretty strong. I scratched my face and had cosmetic surgery inside my mouth. All the rest is fine. Thanks to people, who helped me after the crash.
It would be nice if the carts where constructed to allow the pilot put the keel support even lower for small glider.
Yeah. She got reamed.http://ozreport.com/15.096
Tail action
Accident?Davis Straub - 2011/05/16 12:36:18 UTC
Hitting the tail with the keel support (Souther field)
A few comments on Julia's accident.
In any of her previous extensive international experience with aerotowing from a cart did anyone instruct her how to trim a glider on a cart or check to see that hers was?First. Because of her previous extensive international experience with aerotowing in a cart she thought it was normal and natural to at least half the time feel pinned to the cart when towing. She hadn't asked any experienced aerotow pilots whether this was in fact normal. (Of course, it isn't).
What this REALLY means is that at least half of the aerotow operators she's encountered in her previous extensive international experience have been negligent in providing a safe operating environment.Second. The small Aeros glider that she flies has a small control frame with down tubes (uprights) that are five centimeters (two inches) shorter than the Wills Wing down tubes used on the T2 144. This means that even at the lowest setting for the carts she has a lower angle of attack than other pilots in "normal" sized gliders.
Duh.This means she is likely to experience being pinned to the cart. She, and others like her need carts that allow for lower keel supports.
- The fact that nobody else was complaining about getting his keel dented indicates that this is ONLY a problem if the cart can't be trimmed properly for the glider. She's putting a lot of weight and downward force on the front end of the cart and there's no clearance between her keel and the tail bracket.Third. Witnesses noticed that back of Julia's cart bouncing in the semi rough grass field. They noticed it pushing up her keel. Black marks and dents on the keel indicated that the keel was being hit by the keel support. One way that others have solved the problem of a bouncing keel support is to deflate the rear tire. The issue of a bouncing keel support pushing up the keel is much more problematic on rough fields like at outlying airfields rather than flight parks. Carts used at rough fields need different design criteria than those used at smooth flight parks.
- See the guys at Ridgely for tips on ensuring that the rear tire is deflated at all times - just like the front ones. They're the pros.
Yeah.Fourth. The tug got off the ground before the pilot came up off the cart. This is a very bad sign. I have never seen it happen. It means that you are seriously pinned to the cart.
