Engine Falls Off but Jetliner Carrying 145 Lands Safely : Air travel: Incident occurs over Florida on flight to Minneapolis. Ground search fails to find 3,500-pound component.

The right rear engine fell off a Northwest Airlines Boeing 727 jetliner Thursday as it flew 35,000 feet above Florida, forcing the plane carrying 145 people to make an emergency landing in Tampa. No one aboard was injured.

The 3,500-pound engine, one of three on the aircraft, fell somewhere near Cross City, between Jacksonville and Tallahassee, airline officials said.

Douglas Miller, a spokesman for the Minneapolis-based airline, said that officials will not know why the engine fell off until an investigation is completed. Safety investigators had not found the engine, which is 12 feet long and 4 feet in diameter, by late afternoon Thursday.

Miller said that Flight No. 5 took off from Miami at 8:30 a.m. and was bound nonstop for Minneapolis with 139 passengers and a crew of six aboard. Northeast of Tallahassee, the pilot radioed air traffic controllers, informing them that he had lost an engine. The plane was diverted to Tampa and landed shortly before 10 a.m.

Mark Weingartner, a passenger returning to Minneapolis from the Orange Bowl, said that the plane shook and he felt a bump similar to driving over a pothole in a road.

“I was sitting next to the window, but it was cloudy at the time, so I didn’t see anything,” he said. “The captain came on and said that one of our engines had just failed--he called it failed--and he said there was no problem, that we could fly on two engines, but that they were going to take us down in Tampa.”

“The captain reported a compressor stall in engine 3, and that was the first indication of any trouble,” Miller said, adding that the crew reported no unusual vibrations or steering problems as a result of the engine failure. “According to procedure, he attempted to restart that compressor. About that time, passengers in the rear of the cabin noticed a loud bang. That may have been when the engine separated from the plane.”

He said there was no evidence of an explosion and no report of major structural damage to the rest of the plane. “I saw pictures, and it looked like the engine made a clean break from the rest of the aircraft,” he said.

Miller said that the plane was 14 years old, about average for Northwest’s fleet. He said company officials were pulling together the plane’s maintenance records for FAA officials and that there were no details on the engine’s repair history.

Federal Aviation Administration spokesman Fred Farrar said the engine loss in flight was the fifth such incident since 1983; it was the second involving a Boeing 727 and fourth involving a Boeing-made aircraft.

The earlier 727 incident occurred on April 16, 1985, over Deming, N. M., Farrar said, noting that officials suspect the engine was struck by “blue ice.” Blue ice is created by the fluid from a leaky lavatory, which freezes at high altitude and may be sucked into the engine compressors, stalling the engine.

“The wrenching motion of the stalled engine may have torn the engine off,” Farrar said. “We don’t know for sure but that’s what we suspect happened in that (previous) incident.”

In the two other incidents involving Boeing planes, the engine bolts were improperly fastened to the fuselage. Both involved Boeing 737s, with one mishap occurring Dec. 5, 1987, over Deptford, N. J., and the other Jan. 20, 1989, on takeoff at Chicago’s O’Hare Airport, Farrar said. The fifth incident involved a Fokker-28 aircraft in 1983.

Augustine Calatrone, a passenger on the aircraft involved in Thursday’s mishap, said that the plane shook briefly as though it had hit a turbulent air pocket. “It just stopped, like that. Then I think I felt shocks two or three more times. I was asleep. The only thing it did was wake me up. I thought it was just the wind,” Calatrone said.

Boeing 727-100 Length: 133 feet, 2 inches Wingspan: 108 feet Engines: Three rear-mounted Pratt & Whitney JT8D-7 turbofan engines with 14,000 lbs. thrust each. Range: Up to 2,650 miles Passengers: Up to 139 First flew: 963