U.S. wants airlines to focus more closely on wiring
Sat Oct 8, 2005 7:16 AM IST
By John Crawley

WASHINGTON (Reuters) - U.S. aviation regulators want the industry to pay closer attention to aircraft wiring that could pose risks for electrical failure and fire, especially on older planes.

The Federal Aviation Administration this week proposed new maintenance, inspection and design standards that would require airlines and manufacturers to analyze aircraft wiring with the aim of making it more fire resistant and easier to pinpoint and correct problems.

Although aircraft design standards are rigorous, wiring is generally considered part of the components they power, like engines or cockpit controls. Maintenance inspections have never given wiring special attention as a separate system.

Current inspection requirements are too general and there is too little attention paid to the impact of how wiring modifications on one part of a plane might affect other parts of the same aircraft, the FAA said.

The new regulation, if adopted, would allow airlines to do more work on wiring at fewer intervals.

"There will be more efficient planning of maintenance programs and less down time for aircraft," said FAA spokesman Hank Price. "Instead of doing it (piecemeal) everyone will come under one umbrella."

The agency estimated the cost of the new program at $474 million over 25 years. But it said airlines should save nearly $800 million from retooled maintenance procedures and improved safety.

Between 1995-2002, there were nearly 400 aircraft wiring failures, the FAA said. Loose, chafed and broken wires account for roughly 84 percent of all wiring problems.

Damaged wiring can be a fire hazard, while engine oil, hydraulic fluids, galley spills and bathroom fluids can coat wire bundles, making them grimy and attracting dust.

Wiring prompted fresh concern after the 1996 TWA Flight 800 explosion. Investigators believe sparks triggered by a wiring failure ignited vapors in the jumbo jet's center fuel tank. The plane broke apart over the Atlantic off New York, killing all 230 passengers and crew.

Two years later, SwissAir Flight 111 crashed off Nova Scotia due to a fire. While investigators never determined an exact cause, suspicion centered on an electric cable.

The disasters spawned safety initiatives, including fuel tank modifications. But post-crash analyses revealed wiring problems may not always be tied to age. They can also be linked to installation and maintenance shortcomings.


http://tinyurl.com/atvyn

quote:

They can also be linked to installation and maintenance shortcomings.

In the case of sr 111, extremely sloppy installation of an entertainment system into the main bus of the aircraft.

New Rule Targets Explosive Wiring Issues

By Russ Niles
Newswriter, Editor

Almost ten years after an electrical fault is suspected to have caused the center tank of a TWA Boeing 747 to explode off New York (killing 230 people), the FAA has come up with a new set of proposed regulations aimed at ensuring (encouraging) airlines and manufacturers to better look after the lifeblood of their airplanes. The Notice of Proposed Rulemaking would essentially treat wiring as a separate system, rather than as part of the other systems, thus boosting inspection, maintenance and design requirements that the FAA claims will actually save the airlines money. "There will be more efficient planning of maintenance programs and less down time for aircraft," FAA spokesman Hank Price told reporters. Instead of patching up wiring as needed, the new regimen would require more work to be done at fewer intervals. The changes will have a direct cost of $425 million over 25 years but Price said the efficiencies afforded will actually save the airlines $800 million. Besides the TWA flight, more than 400 wiring failures have been documented in airliners, including the downing of Swissair Flight 111 off Nova Scotia in 1998, which was believed to have been caused by overheated wiring in the plane's entertainment system.


http://www.avweb.com/newswire/11_41a/briefs/190747-1.html