747SP dive incident, 1985 (was: Fastest airliner ?)

From:         msb@sq.sq.com (Mark Brader)
Organization: SoftQuad Inc., Toronto, Canada
Date:         08 Aug 95 02:18:27 
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Karl Swartz (kls@ohare.Chicago.COM) writes:
> (The China Air 747SP which went into a dive over the Pacific
> on February 19, 1985, after flaming out all four engines, is often
> speculated to have gone supersonic, but the accident report concludes
> that the aircraft probably stayed subsonic.)

In "The Final Call: Why Airline Disasters Continue to Happen",
(Pantheon, 1990, ISBN 0-679-40174-1), author Stephen Barlay
spends several pages on that incident.  He says that while the
crew *thought* they had suffered a quadruple flameout, the NTSB
investigation came to quite a different conclusion.

The incident occurred near the end of a nonstop flight from Taipei to
San Francisco.  It began with a bit of clear air turbulence, causing
the airspeed to fluctuate.  At some point the autopilot "decided" to
increase engine power to maintain speed, but #4 engine did not respond.
The flight engineer soon decided that it had flamed out, but according
to Barlay paraphrasing the NTSB, it actually "was in a hung condition
due to the way it had been operated".

Now the real mistake: the pilot did not turn off the autopilot.
According to an account I remember from somewhere else, its priority
was to maintain altitude, but the plane's altitude of 41,000 feet
was higher than its ceiling for flight on 3 engines.  In any case,
the airspeed dropped to the point where the pilot feared a stall,
and he responded by putting the nose down *via the autopilot controls*.

The autopilot was now way outside its operating parameters, and the
plane went out of control, rolling inverted and then diving, with
heavy G-forces, into clouds.  The crew became disoriented and did not
realize just what was happening.  The flight engineer reported flameouts
on the other three engines, but (according to the NTSB according to
Barlay) he was again wrong about that.

The ground came into view at 11,000 feet, and the pilot was than able
to correct its attitude and pull out of the dive.  An engine restart
was performed, apparently successfully (well, the engines were working
after it) and the flight proceeded to San Francisco.

Mark Brader           \"The age of chivalry is gone. That of sophisters, econ-
msb@sq.com             \ omists, and calculators, has succeeded; and the glory
SoftQuad Inc., Toronto  \ of Europe is extinguished for ever." -- Burke, 1792

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