ABCNEWS ON TV
SEND PAGE TO
WIRE:10/11/2000 16:26:00 ET
Wire Cracks Found in Tests of Older Jets
|FAA To Look Again At Airplane Wiring
this had been their first response)
|Wednesday October 11 1:44 PM ET
Study Shows Need for Wiring Upgrade Back to Story
By RANDOLPH E. SCHMID, Associated Press Writer
WASHINGTON (AP) - Inspections of wiring on 81 airliners found ``room for improvement'' but no immediate safety problems, the Federal Aviation Administration (news - web sites) reported Wednesday.
While cracked insulation was found on wires in six recently retired planes, the cracks did not necessarily represent a hazard, said Elizabeth Erickson, director of aircraft certification for the Federal Aviation Administration.
``Cracked wires do not, in and of themselves, represent an immediate safety problem,'' Erickson said in a discussion of the agency's program to study aircraft wiring. But, she added, ``they are of concern to us.''
The FAA launched a program two years ago to study wiring in aircraft, particularly aging airliners. The advisory committee for that effort is meeting in Washington this week to review progress.
The National Transportation Safety Board has concluded that the destruction of TWA flight 800 four years ago, killing all 230 aboard, resulted from a fuel tank explosion, probably caused by a short circuit.
The FAA program studied airliners during their regular maintenance stops, looking specifically for wiring problems
``They found no immediate fleetwide safety issues, but they found definite room for improvement in maintenance practices,'' Erickson said.
Not all the problems were caused by aging, she added, noting, for example, that in some cases wiring insulation had been unintentionally damaged by work crews in tight areas.
``We found a need for better targeted inspection out there in the fleet,'' she said.
Erickson said Boeing and Airbus have advised airlines of problem areas so they can improve wiring inspections and noted maintenance reports are being changed to more completely show repairs made on wiring. The FAA is also improving its training of inspectors to better focus on wiring problems.
Erickson said the agency is also working on the development of new, more sensitive circuit breakers to shut off power when a short occurs in a wire and on technology to check the condition of wires throughout a plane.
Asked about reports that the cracked wiring found on the six retired airliners could mean some planes have hundreds of damaged wires, she insisted that assumption was incorrect.
Those inspections targeted areas where wiring was under the most stress, areas where it was exposed to heat or cramped into a tight areas, she said.
Those findings ``can't be extrapolated to the whole of the aircraft,'' she said.
The detailed wiring checks done on the six retired planes included removal of wiring bundles from various parts of the planes, a step that can't be done on aircraft that are still in service, she noted.
The six planes included an Airbus A300, two DC-9s, a Boeing 747, a DC-10 and a Lockheed L-1011.
Wednesday October 11 4:26 PM ET
Wire Cracks Found in Tests of Older Jets
WASHINGTON (Reuters) - Cracked insulation was found in the wires of six older, recently retired aircraft, but the Federal Aviation Administration (news - web sites) said Wednesday it had no immediate safety concerns.
Engineers removed wires from high-stress areas of the aircraft that were more than 20 years old as part of a government-industry task force effort to determine the extent to which aging wiring may threaten safety.
``Cracks in wire do not in and of themselves present an immediate safety concern,'' FAA aircraft certification director Beth Erickson told reporters, noting that cracked insulation alone need not cause a problem unless it shorts with another wire or the plane.
The aviation industry became sharply focused on wiring after the 1996 crash of a TWA Boeing 747 (NYSE:BA - news) near New York that was blamed on a likely short circuit in its center fuel tank.
The investigation of a fiery Swissair (SWSZn.S) MD-11 crash off the east coast of Canada in 1998 has focused on wiring in the cockpit.
USA Today reported Wednesday that, in one of the aircraft examined, a Lockheed L-1011 wide-bodied jet, four cracks were found in every 1,000 feet of wire tested.
The newspaper calculated the aircraft could have more than 3,100 wiring cracks, assuming roughly 150 miles of wiring in the whole aircraft.
But Erickson said that number exaggerated the problem as the wire was taken from problem areas involving heat stress or tight turns that can abuse wire insulation.
``It's not right to extrapolate,'' she said.
FAA declined to make the report available saying it was being delivered to the task force later Wednesday in preliminary form.
Erickson said FAA had issued numerous directives on improving wiring in specific aircraft and more would likely be forthcoming as more data became available.
The other five aircraft involved in the intrusive inspections were an Airbus (ARBU.UL) A300, a DC-9, a 747 and a DC-10.
As of last month, U.S. airlines were operating 1,709 jets that are at least 20 years old, according to Christine Francoeur, president of Jet Information Services, which publishes the World Jet Inventory. Worldwide, airlines were operating 3,270 jets that old, she says.
FAA said a separate non-intrusive inspection of 81 aircraft still in service had shown no fleet-wide safety concerns, but had pointed to a need to improve maintenance practices, training and better reporting of wire faults.
Work was also proceeding on an advanced circuit breaker that could detect damaging wiring shorts sometimes undetected by existing technology, or detected after major damage has occurred.
Two contracts have been issued to companies working on devices that will allow maintenance workers to test wires for faults without disturbing wire bundles. Experts say the very act of moving wires around to inspect them can cause damage.