Hours before the pilots of an American Eagle commuter plane that crashed spoke of engine trouble, mechanics had to repair one of the engines because it wouldn't start.

The left engine was fixed and the plane took off from Raleigh for Greensboro, American Eagle spokesman Marty Heires said late Thursday. On the return flight to Raleigh, the twin-engine Jetstream 3200 crashed in fog and drizzle, killing 15 of the 20 people aboard.Heires said there was no connection between the starting problem Tuesday and a possible engine failure. He said the nature of the engine repairs was unknown because the repair logs were lost in the crash of Flight 3379.

"Clearly the plane was safe to take off," he said after an National Transportation Safety Board briefing.

The cockpit voice recorders show the pilots talked about a "flameout," or engine failure, just before the crash 31/2 miles from Raleigh-Durham International Airport. It was not known which engine they were talking about.

Also Thursday, American Eagle suspended all flights from Chicago and some from New York's Kennedy Airport until Jan. 4 because pilots of planes that had been shifted there said they needed more training to fly in cold weather.

The airline had brought in Saab 340 turboprops from Nashville, Raleigh-Durham and Miami because of concerns that ATR turboprops might not be safe in icy weather. An American Eagle ATR plane crashed in icy weather on Oct. 31 in Indiana, killing all 68 people aboard.

At the briefing, NTSB Chairman Jim Hall said investigators had recovered a piece of sheet metal wedged in part of Flight 3379's left engine. He said it was unclear when the metal became lodged in the engine. He would not speculate on whether it was a factor in the crash.

A trainee air traffic controller was guiding Flight 3379 before it crashed, but Hall said interviews with tower officials showed the controller was under supervision and that the flight was handled normally.