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From: scw@ucla-cs.UUCP
Newsgroups: net.aviation
Subject: Re: de Havilland Comet at ORD?
Message-ID: <7234@ucla-cs.ARPA>
Date: Tue, 22-Oct-85 16:45:28 EDT
Article-I.D.: ucla-cs.7234
Posted: Tue Oct 22 16:45:28 1985
Date-Received: Sat, 26-Oct-85 07:34:09 EDT
References: <338@ektools.UUCP> <33300001@hpfcmp.UUCP> <2987015c.1de6@apollo.uucp> <1305@poseidon.UUCP>
Reply-To: scw@ucla-cs.UUCP (Stephen C. Woods)
Organization: UCLA Computer Science Department
Lines: 23

In article <1305@poseidon.UUCP> brent@poseidon.UUCP (Brent P. Callaghan) writes:
>>I used to work on [...] be for quite a while.  I don't know if
>>any Electras are still in civilian use or not.
>
>A Lockheed Electra crashed on takeoff at Reno, Nevada last year.
>
>Weren't the original series of crashes attributed to the
>wing falling off ?

Actually the crashes were due to harmonic feedback between the engines and the
wing at a very specific engine speed. The fix was simple, they added about
80 pounds of weight at the front of the nacelles which changed the frequency
that they would cycle at.

The problem was solved when an Electra had the cycle start just as the pilot
pulled the throttles to begin a letdown.  The NTSB said that the wing/engine
on that aircraft completed only  3-4 cycles of the swing before the engine
passed out of the critical speed range. In those few cycles the wing popped
about 45% of the skin rivets and bent the Main spar almost 2 inches.

The wing on the electra was ALMOST exactly the same as the wing on the C-130
the major difference is that the engines on the C-130 are mounted underneth
the wing and the L-188 engines are mounted above the wing.