Postby kill_devil » Wed Nov 22, 2006 1:48 pm
I have to echo what Leprachaun says, and have put Dreamer's question to the BMAA.
The placarded Vne (never exceed speed) happens to have a 10% safety factor built in, which probably explains how Alex got away with it.
His Quik will have been test flown to 115mph x 1.1 = 126.5 mph by the factory. This means he was within the tested limits when he reached 125 mph, though I wonder whether he knew this at the time, it being only 1.5 mph from the Outer Limits!
Remember dynamic pressure increases by the square of the speed, so Alex subjected his wing to 18% more stress: 125*125/115/115=1.18. Any gust loading could easily double this.
From his photo he appears to be flying the older variable reflex Quik wing with in-flight adjustable lufflines (rather than the new motorised trim system), and so he was relying on them being correctly adjusted to provide the positive pitch moment to be sustained during the dive. Wisely he did not pitch down more than 30 degrees.
Last week I went solo in my own Quik GT-450. As part of the training they put you into an 80 to 90 mph spiral dive and then tell you to recover! That's OK, as it's well within the flight envelope.
In Alex's case I think he went too close to the edge.
"The hardest thing about flying is the ground"