On Friday, February 2, 2018 at 6:11:23 PM UTC-5, John Cochrane wrote:
Meanwhile, when we put in a low speed start system and higher finishes, those crashes ended.

We can debate the finish gate (actually, let's not!). But I've gotta question what data you have on high-speed start crashes. I didn't see any in your PPT (I'm not sure when we ditched the start gate but it was still around for at least part of your study period).

I only recall two. One in Minden in the 1970s caused (IIRC) by not locking the main pins so they ratcheted out and departed the fuselage (pilot bailed out successfully). The other was a PIO at Fairfield in the late 90s (?) when a handheld radio got loose in the cockpit and the pilot reached for it, losing control of the glider and departing the cockpit through the hole in the canopy created by the errant radio (also a successful bailout).

Oh, and I'm told there was a pilot who fluttered an early ASW 20 elevator in the 1980s and landed uneventfully to discover some internal damage in the control system.

High-speed starts always sounded lethal whenever CAI and the then Rules Committee were trying to justify mandating GPS flight recorders. Everyone just KNEW high-speed starts were dangerous! To me that's analogous to your average bystander thinking it simply must be dangerous to fly an aircraft without an engine.

I've actually been a lot more uncomfortable on the edge of start cylinders winding around in a gaggle faster and faster with half a dozen gliders all trying to stay a few feet below the top, watching the clock, looking out for at least half a dozen more orbiting in a different part of thermal plus another half dozen bumping the thermal on their way out of the cylinder. A few feet too high? No problem with the gate: just push over on your start run a little sooner. With the cylinder, get the brakes out and ease back down through the gaggle, but not too low, while watching the clock again. I'm not sure that's progress in terms of safety. Nothing comes for free. At least with the start gate, we knew precisely where the start traffic would be.

It's those unintended consequences again.

Chip Bearden