Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!watmath!clyde!burl!ulysses!allegra!bellcore!decvax!genrad!mit-eddie!godot!ima!pbear!peterb From: peterb@pbear.UUCP Newsgroups: net.aviation Subject: Re: Re: China Airlines 747 Message-ID: <87@pbear.UUCP> Date: Sat, 9-Mar-85 05:54:47 EST Article-I.D.: pbear.87 Posted: Sat Mar 9 05:54:47 1985 Date-Received: Mon, 11-Mar-85 07:01:14 EST Lines: 41 Nf-ID: #R:alice:-344200:pbear:26200001:000:2194 Nf-From: pbear!peterb Mar 8 15:40:00 1985 Actually you have hit on a point that was all to evident in a 727 mishap a while ago. I don't remember the airline or the year, but a mysterious accident occured when for no apparent reason the 727 rolled over and dived straight down from about 35000-40000 feet shortly after entering cruise. Another 727 did the same thing a while later and this time they figured out the reason. 727's were not originally designed to fly at such high altitudes so when they do they tend to plow along in a nose up attitude since the thin air does not create enough lift in a level attitude. this was no real problem until the fuel crunch, and pilots and airlines realized it. Somebody came up with an illegal brainstorm: put out 2 degrees of flap and the wing now generates enough lift to fly level and lower feul consumption, reduce air time, redice time to cruise, etc. This was great(apparently) but there was a minor flaw in it. On the 727, the flap and slat circuits operate together under one control. So at 3XX00 feet, in order to put out 2 degree of flap without having the slats open they pop the circuit breaker to the slats. In the incidents the bozos doing this either didn't pop one of the breakers or forgot or whatever. But the end result is rather astonishing. Opening a slat at about 300-400 knots on a 727 is self-destructive. Apperently one slat deployed and quickly disintigrated. This caused a highly asymmetric lift condition(with an entire leading edge gone, there's no choice) which was so bad that FULL aileron/spoiler deflection could not overcome the imbalance, and hence the plane barrell rolled over into the ground. The FAA inspectors were puzzled when they found that the flaps were out a little, and that the slats were gone. There was no way to determine of they were deployed or not, they were just ripped out, actuators and everything. When they rebuilt the cockpit and examined it, lo and behold one of the slat breakers was popped. Through some deductive reasoning they figured the rest. The incident with the China 747 sounds a little fishy to me, I wouldn't be suprised to find that they pulled a real stupid move. Peter Barada ima!pbear!peterb