An oil leak in an auxiliary power unit in the cockpit caused the smell of smoke in a St. Louis-bound TWA airliner that turned back to John Wayne Airport during the weekend, a spokesman said.
The leak was minor and occurred in a unit that supplies electrical power while the DC-9 is on the ground, TWA station manager Marty Larsen said.
TWA Flight 336, with 57 passengers aboard, took off at 1:35 p.m. Saturday and returned to the airport about 10 minutes later.
On the ground, the flight crew also found an electrical problem in a microwave oven used to heat food. The oven and the power unit were not needed on the flight and were put out of service, Larsen said.
The plane took off again 2 hours later.