Wiring in the MD-11 Fleet

As part of the FAA's ongoing efforts to address the MD-11 wiring concerns raised by the Swissair accident, the agency ordered inspections of wiring and insulation in the cockpit and cabin on all U.S. operated MD-11s. The FAA continues to work closely with the Canadian Transportation Safety Board (CTSB) and NTSB on
potential MD-11 safety issues. The CTSB suggested a closer look at the wiring in the MD-11 fleet. Several MD-11s were examined as part of the Swissair accident investigation. Based on the wiring discrepancies found, the directive requires U.S. operators to perform the inspections, and make any necessary repairs, within
60 days and report findings to the FAA. Worldwide, 174 MD-11s are affected by this AD, 65 of which are U.S.- registered. Foreign carriers include Swissair, Varig, JAL, KLM and EVA. U.S. carriers are American, Delta, FedEx, and GATX. The cost to U.S. carriers is estimated at $720 per aircraft, $46,800 total for the U.S. fleet.

Wednesday, February 3, 1999

FAA orders tackle repeat problems

By STEPHEN THORNE -- The Canadian Press

OTTAWA (CP) -- Airworthiness directives issued by the U.S. Federal
Aviation Administration are falling short of their marks, says an agency
member who sees the same problems being repeated across the industry.

A directive last Thursday called for a one-time inspection for chafed or
otherwise damaged wires in MD-11 planes like Swissair's Flight 111 that
crashed off Nova Scotia on Sept. 2, killing 229 people.

But a one-time inspection is not enough, says Ed Block, recently appointed to
an FAA task force on electrical wiring.

"Why isn't there a stated repeat in 60 days and every 60 days thereafter? If
there's a chafing problem, when is it going to show up? This one-time
inspection's going to do it?

"If the issue is repeated rubbing or chafing or shorting, it should be a periodic
inspection," he said in an interview from Pennsylvania.

"These airworthiness directives are like handwriting on the wall, or tremors
before an earthquake."

He also noted that the wiring directives did not specify what insulation was
suspect.

None identified the type of insulation involved -- Kapton -- and therefore they
didn't alert operators of other aircraft types using the same electrics.

"If they put out an airworthiness directive on a Pratt and Whitney engine,
they'd look at all the Pratt and Whitney engines," said Block.

"If they have a frailty or shortcoming in a wire type, then why wouldn't they
look at all the different models that use that type wire?"

Block said similarities between 1991, '92 and '99 directives are striking.

In 1992, a directive was issued to inspect wiring between the cockpits and
cabins of 747 Model 300, 400, and 500 aircraft -- the same area of concern as
currently on MD-11s. It required operators to repeat the inspection "at
intervals not to exceed 120 days."

In 1991, the FAA ordered Boeing's 400 series of 747s inspected for chafing
and wear similar to that found in the MD-11s. The directive, under study by
crash investigators, cited the wire bundle installation in the 747s' advanced
cabin entertainment and service systems.

"The amendment is prompted by reports of chafed wiring resulting in short
circuits which led to burned wire bundles," the FAA said. "This condition, if
not corrected, could result in smoke and fire in the passenger cabin."

The directive last Thursday came after Canadian and U.S. investigators
found evidence of wire insulation damage in more than a dozen of the
McDonnell-Douglas planes, including some belonging to Swissair.

"This action requires a one-time inspection to detect discrepancies of certain
wiring and insulation in the cockpit and cabin, and repair, if necessary," said
the directive.

"The actions specified in this (directive) are intended to prevent electrical
arcing of certain wiring, which could cause fire and-or smoke in the cockpit or
cabin."

Flight 111's pilot reported cockpit smoke before the MD-11 plummeted into
the ocean. Investigators have focused much of their attention on the plane's
electrical and entertainment systems.

Canadian authorities have found signs of electrical arcing in wires from the
downed jet that could be the result of damage such as cracks or chafing.

Kapton is hard, sometimes brittle, and can wear away softer insulations with
flight vibration. It can also be easily damaged with handling and has been
known to break down with age.

Swissair's high-tech entertainment system used soft Tefzel-insulated wires. It
was installed by a California-based company early last year.

The entertainment systems aboard the 65 jumbo jets affected by the 1991
order were installed by Boeing when the aircraft were built.

The problems should not be related, said a Boeing spokesman.

"It's installation, not insulation," Russ Young said from Seattle.

Indeed, a Boeing service bulletin dated Aug. 29, 1991, advised operators to
inspect the 747s for correct installation as well as damaged insulation.

Swissair crash warning to airlines

Safety experts investigating the Swissair crash off the
coast of Canada in September have called on the US
Federal Aviation Administration to check cockpit wiring
in all Boeing MD-11planes, like the one that crashed,
following the discovery of new clues.

The National Transportation Safety Board (NTSB) said
electrical wiring recovered from the crash showed signs
of arcing damage - a short circuit - similar to faults found
in other MD-11s.

The request comes as European aircraft manufacturer Airbus announced a major rise in sales - in contrast to
Boeing's dip in fortunes.

Swissair Flight 111, bound from New York to Geneva,
crashed in the Atlantic Ocean near a Nova Scotia
fishing village on 2 September, killing all 229
people on board.

The crash occurred 16 minutes after the crew had
reported smoke in the cockpit.

In a letter to the FAA, the NTSB said that inspections of
all MD-11s should be carried out on an "expedited
basis", focusing on two cockpit circuit breaker panels.

In a statement, the FAA said it had already started to
address the wiring concerns.

Usually, airline authorities around the world follow the
recommendations of other air safety agencies.

Key areas of damage discovered in the wreckage
included a power feeding wire in an overhead circuit breaker and in the entertainment system.

The airline voluntarily cut off the entertainment system in October when the first indications that it may have
played a part in the tragedy.

Investigators have already made other wiring-related safety recommendations to Boeing and Swissair.

In November, the FAA ordered US airlines to examine
light dimmer switches for faults which could cause
overheating and smoke.

A month later, the agency asked airlines and Boeing to
ensure that front passenger doors did not nick or fray
wires when they were opened.

Airbus challenge Boeing

Meanwhile, Airbus Industrie reported that it was in a
position to compete on an equal basis with Boeing and
command half of the world's market.

Airbus' results show sharp rises in sales and orders for
its planes, just weeks after Boeing said it planned to cut
jobs and production levels.

The European concern received 556 firm orders for new
aircraft worth $39bn, up from 460 orders worth $29.6bn
the previous year