david, i can't read air traffic control radar but what that shows is that as that plane was ascending to 36,000 feet it was probably flying about 100 miles an hour too slowly to be at that altitude. what problems could that create if that's in fact what happened? >> well it's a pretty simple problem because what happens is the air over the top of the wing is what creates the lift. the speed of the air over the top of the wing. if the air is not going well over the top of the wing not going at a high enough speed there's similarly not enough lift to lift the aircraft up and that's what happens in a stall is the air is either disrupted -- >> the word you used was "stall." so it could cause the plane to stall if it's fly too slowly at that altitude? >> a stall in this situation is much worse. in n a stall situation if your power is not on, if you pulled power back and the aircraft is angling up and it stalls that's a recoverable stall. in this situation the power was evidently on full power trying to climb and it had climbed too rapidly and that's when it stalled. if it stalls with power on it's