At least two persons were reported killed last night when a small jet plane crashed in the McLean area of Fairfax County, apparently after exploding in flight, according to county fire officials and witnesses.

Air traffic controllers said that the plane was not a commercial flight. Witnesses said it appeared to be a small craft that may have carried no more than two persons.

The crash occurred about 8:40 p.m. Many persons throughout Northern Virginia and in parts of Montgomery County reported hearing a terrific explosion and seeing a brilliant fireball in the night sky.

About the same time, Washington air traffic controllers reported that they had lost contact with an aircraft about a mile northwest of Tysons Corner.

Part of the debris touched off a blaze in a house in the McLean Hunt subdivision, according to firemen.

No injuries were reported initially as a result of the fire at 1171 Old Stable Rd., the home of Mr. and Mrs. Dennis P. Clarke and their children.

The house was destroyed, according to John Bowen, a neighborhood resident. Only the chimney was left standing, he said.

But the Clarkes were across the street at the time, he said.

"It's a miracle," said Bowen.

Bowen said debris from an airplane lay strewn about the neighborhood, with most of it in a four-acre park behind the Clarke's house.

He said the disposition of the debris indicated that the crash occurred in or near the park.

Bowen said he saw part of an airplane wing nearby, and it appeared to have been made of white colored aluminum.

He said that some of his neighbors reported that a second house in the area may have been damaged as a result of the crash, but no address was immediate available.

The area of impact was sealed off by authorities shortly after they reached the scene.

Neighbors who went immediately to the crash site said there were indications that the plane had two engines.

Initial reports of two deaths came after two bodies were found in the cockpit of the plane, which was said to have been owned by a private business corporation.

However, there were indications that a third persons may also have died in the crash.

The third victim may have been thrown from the plane before it came to rest, authorities speculated.

There were no immediate indications as to the cause of the explosion and crash.

The explosion apparently occurred as the plane was at a relatively low altitude and according to one air traffic controller, it had just taken off from National Airport.

A witness, Col. Robert F.[Word Elligible] kraus, 56, of McLean, said the blast appeared to be "right at the base of the overcast, which appeared to be at about 2,000 feet."

"There was a distinct explosion of orange flame," he said" . . . It appeared to be almost total disintegration. You could see the debris falling straight down. It was all over in five seconds."