FAA ORDERS CHECK OF BOEING 737S.

Byline: Daily News Staff and Wire Reports

The Federal Aviation Administration issued an urgent order to airlines Thursday to inspect the wiring of their older Boeing 737s after learning that sparks from a high-voltage power line in the wing tank of a Continental Airlines plane had burned holes in the surrounding conduit, in which jet fuel leaked.

The discovery was confirmed Monday by Boeing Co., to which Continental had sent the conduit, and Thursday the aviation agency gave the airlines seven days to inspect the 152 planes in this country with more than 50,000 hours of service. Each inspection will take 15 hours and will require two airline mechanics, the agency said, making it virtually certain that some planes will be grounded to comply and airlines will be forced to scramble to meet their flight schedules.

``For this kind of a failure, there's a potential for fire or explosion,'' said Richard Breuhaus, Boeing's chief engineer for fuel system safety. ``That's why we're reacting to it as quickly as we are.''

Locally, flights at the Burbank-Glendale-Pasadena Airport will be unaffected because the older aircraft addressed in the inspection order has been phased out, said Sean McCarthy, assistant director of public affairs at the airport.

``Our service has not been hampered at all. Everything is running smoothly,'' McCarthy said.

Flights at Los Angeles International Airport might be affected by the order, with the possibility of a few canceled flights, said Tim Pile, an FAA spokesman based in Seattle.

But Pile said two of the major airlines using the older plane, Southwest and United, have stated that they will minimize the effects and, if necessary, notify passengers with reservations in advance of any changes.

``They will be able to schedule the inspections with a minimal impact,'' Pile said Thursday. ``The bigger the company, the more they can creatively juggle their airplane schedules with little interruption.''

The wiring problem was discovered several days ago as a result of a fuel leak it had caused on the Continental plane. On learning about it, the aviation agency also issued rules covering wiring inspections on several other Boeing models that it had been considering for months as part of a program growing out of the crash of Trans World Airlines Flight 800 almost two years ago. That plane was a 747.

But experts said Thursday that the troublesome mechanism discovered on the Continental plane was probably not involved in the TWA crash. The Continental plane probably had sparking from the high-voltage line because insulation had been rubbed away by vibration, but the conduits in the 747s have an extra layer of Teflon sleeves to reduce such rubbing, experts said. In addition, inspections of the conduits of other 747s over the past few months have found no sign of damage.

The wires in question carry 115 volts and power the pumps that deliver fuel from the wing tanks to the engines. The conduits are about half an inch in diameter, and run several feet through the tanks; the one in the Continental plane was made of aluminum. Boeing has ruled out corrosion or abrasion as the cause of the holes. Thomas McSweeney, the director of aircraft certification at the aviation agency, said the holes apparently were made by electrical sparks, although tests were continuing.

FAA engineers had believed that if a short developed, it would trip a circuit breaker before the electricity burned through the conduit, but they have been proved wrong.

Since the TWA incident, investigators have grown more concerned that as planes age, the insulation on their wiring may become more brittle and prone to crack, but McSweeney said Thursday that the problem with the 737s did not involve aging. Instead, he said, it was abrasion of the insulation, brought on by engine vibration.