Re: Virgin 747 birdstrike

From:         sandee@Think.COM (Daan Sandee)
Organization: TMC
Date:         21 Dec 95 14:01:43 
References:   1 2 3 4
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In article <airliners.1995.2014@ohare.Chicago.COM>, kls@ohare.Chicago.COM (Karl Swartz) writes:
|> >Is it really true that two-engine shutdowns can be coped with? I seem
|> >to recall an El Al 747 freighter that lost two engines shortly after
|> >take-off from Schiphol in October 1992. If memory serves, it ended up
|> >crashing into a residential building short of the airport while trying
|> >to return to it.
|> Your memory serves well regarding the end result.  However, that was
|> not simply a case of two engines shutting down -- the #3 (starboard
|> inner) engine separated from the wing, hitting and detaching the #4
|> (starboard outer) engine on its way.  I believe there was also wing
|> and probably hydraulic damage that hindered the pilots' ability to
|> control the aircraft.  They did not dump fuel, so the aircraft was
|> very heavy, thus even harder to control.
|> United flight 811 was about an hour out of Honolulu on February 24,
|> 1989, when a forward cargo door separated from the aircraft, peeling
|> away a fair chunk of skin in the process.  9 passengers were ejected
|> and they along with other debris were sucked thru the #3 and #4
|> engines, which failed but did not depart the airframe.  Despite the
|> airframe damage and loss of two engines (on the same side), that
|> flight returned safely to Honolulu.  The key difference was that the
|> engines did not detach and damage the wing surfaces in the process.

The other important difference was that the El Al flight happened shortly
after take-off with a fully-loaded aircraft and the pilot had no safety
margin (read, speed and altitude) whatever.  The UA incident occurred at
altitude and the crew had ample opportunity to regain level flight at a much
lower altitude (they needed to descend rapidly anyway because of the loss
of cabin pressure.)  It would still surprise me if losing two engines on
a 747 during takeoff (e.g., through bird ingestion) without collateral
damage would be a situation which is regarded as normally recoverable.

Daan Sandee                                 
Cambridge, MA