From Staff and Wire Reporta CHANTILLY — Federal investigators

From Staff and Wire Reporta

CHANTILLY — Federal investigators are trying to determine what caused a cover for the engine on a Boeing 737 airliner carrying 120 people to fall off minutes after takeoff from Dulles International Airport.

The pilot of People Express Flight 183, bound for Newark, N.J., with 115 passengers and five crew members, turned around just after 7 a.m. Sunday when a passenger said he saw the casing for the engine under the left wing fly off, according to airline spokesman Ed Stukane.

The pilot did not declare an emergency, Mr. Stuljane said. “He did the prudent thing, and decided to return and have it checked out,” he said. “The passengers were not in danger. ”

The twin-engine Boeing 737-100 jet is equipped with Pratt & Whitney JT8D-7 engines, Mr. Stukane said.

Last week the Federal Aviation Administration ordered inspection of JT8D-15 models following an engine fire that caused a British Airtours 737 jet to crash Aug. 22 after takeoff from Manchester, England, killing 54 people.

A day after the crash, Pratt & Whitney said it had sent a message to all airlines using engine types J78D-1 to JT8D-15, “re-emphasizing earlier recommendations covering inspections and maintenance of the combustors.”

Mr. Stukane described the missing portion on engine No. 1 as a cowling, or an outer shell toward the rear of the engine, which he said may have exposed working parts of the engine.

A photograph of the plane’s engine showed an exposed fuel line. Federal officials hoped to find the casing in the area along the plane’s flight path.

“A passenger noticed the problem, and notified a customer service manager (flif^it attendant) who told the first officer,” Mr. Stukane said. Emergency equipment was called out to the runway, but the plane landed without incident, he said.