One engine of a USAir DC-9 airplane failed on takeoff from Washington National Airport last night, forcing the aircraft carrying 73 people to make an immediate emergency landing at the airport, officials said.

The Buffalo-bound Flight 100 took off at 8:20 p.m. but landed safely eight minutes later and taxied to the airport terminal, airport spokesman David Hess said. There were no injuries among the 68 passengers and five crew members.

Hess said the right Pratt & Whitney engine of the two-engine plane apparently failed on takeoff when the turbine spewed about 20 small blade fragments onto the grass lining runway 18/36, National's main runway.

The hot fragments started a small grass fire on one side of the runway and sparks from that blaze started another small fire on the other side, Hess said.

Firefighters from nearby Alexandria and Arlington helped an airport crew extinguish both fires, which scorched a 70-foot swath of grass, officials said.

The two fires forced the shutdown of the main runway for 51 minutes until 9:11 p.m., Hess said.

USAir spokesman David H. Shipley said passengers on Flight 100 were transferred to another plane and resumed the flight about 90 minutes later.

Officials would not identify the DC-9 pilot, but Hess said the pilot reported feeling a "thump" as the plane left the runway heading south along the Potomac River.

The pilot banked the plane in an easterly direction and approached the airport from the north, Hess said.