FAA says MD-11 map lights a fire hazard, orders them unplugged STEPHEN THORNE

NEW YORK (CP) - Aviation's top regulator has ordered airlines to unplug cockpit map lights on MD-11 jets after Canadian authorities investigating the 1998 crash of a Swissair plane off Nova Scotia found they could start a fire.

Wednesday's airworthiness directive from the U.S. Federal Aviation Administration is at least the 23rd safety order about wiring on the jets since all 229 people aboard Swissair Flight 111 crashed off Peggy's Cove.

There have been 47 wiring orders total in the last decade - an unusually high number.

Ed Block, an aircraft wiring expert and member of an FAA committee on the subject, says the volume of orders affecting MD-11 electrics is a concern.

"It's the most horrendous combination of wiring problems found on any model of aircraft - absolutely, bar none," Block said.

The increase in orders since the September 1998 crash is indicative of a tombstone mentality, he said, where some wiring problems were ignored until a crash forced authorities to act.

The FAA, which dictates industry rule-making worldwide, ordered operators to inspect map lights for broken or cracked bulbs which could lead to smoke or fire.

The map light directive follows a March 2 letter from Canadian investigators to the U.S. National Transportation Safety Board warning of problems with map lights aboard MD-11 jets.

The problems were discovered while officials from the Transportation Safety Board of Canada were monitoring changes in thermal and acoustic blanket insulation, which they determined helped spread fire on Flight 111.

There are 11 map lights on an MD-11. Investigators have not been able to find any from Flight 111's cockpit, said spokesman Jim Harris.

More than a million pieces of the downed aircraft have been found. Evidence suggests a fire may have started in the plane's right-side ceiling, just aft of the cockpit, although the study is not complete.

Pilots aboard Flight 111 enroute to Geneva reported smoke in the cockpit about 53 minutes after leaving New York. The plane's electrical systems began failing about 15 minutes later.

Six minutes after that, the jet plummeted into the Atlantic Ocean.

There are 174 MD-11s worldwide, none flown by Canadian airlines. The jets are manufactured by Seattle-based Boeing Co.

There are about 9,000 Boeing aircraft in service. Block said at least 70 per cent have some degree of defective wiring.

Based partly on the recommendations of Canadian authorities, the FAA has ordered the flammable metalized mylar insulation changed aboard hundreds of jets worldwide.

"During one of the early visual inspections, it was noted that an insulation blanket was in contact with the upper part of the recessed map light installed in the right side of the cockpit ceiling," wrote William Tucker, the TSB's director general of investigation operations.

"The . . . insulation material had been mechanically damaged and, due to continuous contact, had been imprinted with the back of the map light fixture, which houses a halogen lamp."

Insulators on a wire lead to the map light showed possible heat damage, said Tucker, and the left-hand map light showed similar problems.

As a result, the TSB looked at map lights on about a dozen aircraft from two operators:

- Several had cracks in the plastic protective covers on the lights' positive terminal; cracks had been repaired on some lights even though the manufacturer requires replacement.

- In one instance, part of the protective cover was missing and the positive terminal strip was partially melted.

- Mylar blanket insulation was found pressed against many of the light fixtures and showed signs of heat damage.

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-- Martin Thompson (mthom1927@aol.com), April 05, 2000