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Subject: Boeing 747s Inspection Focuses Concern on Corroded Engine Pins<By Don
Date: Fri, 13 Nov 92 04:39:11 EST
Message-ID: <10.1992Nov13.043912@AmeriCast.com>

Boeing 747s Inspection Focuses Concern on Corroded Engine Pins<By
Don Phillips=Washington Post Staff Writer=

A special inspection of the pins that hold the engines to the
wings of Boeing 747 jets has uncovered significant corrosion in
about 20 percent of the pins so far, and the Boeing Co. yesterday
said it has recommended that inspection procedures be tightened.

The Federal Aviation Administration is expected to make the ex-
panded procedures mandatory within the next few days. The new FAA
order will supplement inspections already ordered after an El Al
747 crashed last month.

The FAA has said that cracked pins is one "theoretical accident
scenario" in the crash of the El Al cargo 747 on Oct. 4 in Am-
sterdam. Both engines ripped from the right wing of that plane
several minutes after takeoff, and the jet crashed into a low-
income apartment complex, killing a still-undetermined number of
people.  That crash was similar to a China Airlines crash on
Taiwan Dec. 21, 1991, in which both right engines fell off the
cargo plane.

Dick Johnson, Boeing's director of engineering for the 747 pro-
gram, said airlines have "gone beyond what we asked them to do"
in inspecting and replacing pins, and he said there is no danger
to passengers.

Johnson said that of 2,340 pins inspected - on about 300 planes
of the 950-plane fleet worldwide - about 20 percent were corroded
enough to require replacement. That was "more corrosion than we
expected," he said.

However, he said only 14 pins were found to be cracked, and those
cracks were not severe.

"I think we're being very conservative, but we have to be conser-
vative when it comes to safety," Johnson said.

Four of the 2 1/4-by-4-inch "fuse pins" hold each of four struts,
or pylons, to the 747's wings, and the jet's four engines are
each attached to the bottom of a strut. The pins are essentially
a safety device designed to break and allow the engine to
separate from the plane in case of a catastrophic engine failure,
which might otherwise rip all or part of the wing off.

However, the pins have proved subject to corrosion, which could
lead to cracks and allow the engine to rip off under normal
operation. Boeing has redesigned the pins once, and is now
redesigning them a second time. The third generation of pins
should be available about mid-1993, Boeing said.

The recommended new procedures expand the inspections to the en-
tire 747 fleet. Previously, 747s with General Electric engines
were exempt. The initial inspection on a new plane also would
come sooner - after three years or 3,000 landings, rather than
after 5,000 landings. And first-generation pins, now used on only
about 10 planes, must be replaced regardless of their condition.

The recommendations include inspections of both ends of the pins.
Previously, the requirements could be met with an ultrasonic in-
spection on one end of the pin, but Boeing recommended that air-
lines now physically inspect the other end of the pin, which is
difficult to reach. Johnson said the new inspection procedures
could be performed overnight, so that no planes need be taken out
of service.<02:10 11-13C9999-----

Copyright 1992, The Washington Post.  This story is from the
Washington Post's Capitol Edition On-Line and is not to be ar-
chived or redistributed.

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