Allegheny Airlines flight AL561 departed on February 12, 1979 at 13:00 e.s.t. from Benedum Airport, Clarksburg, West Virginia, for National Airport, Washington, D.C., with Two persons were killed and eight persons were seriously injured; the 25 persons on board.

Allegheny Airlines flight AL561 crashed about 14 sec after liftoff, aircraft was destroyed.

The official weather at the time of departure was: Sky partial obscuration, 1,000 ft overcast; visibility 5/8 mi in snow; wind calm; altimeter 29.89 inHg.

The National Transportation Safety Board determines that the with snow on the aircraft’s wing and empennage surfaces which resulted in a loss of lateral control and a loss of lift as the aircraft ascended out of ground effect.