A Howard County man died instantly yesterday when his single-engine, homemade airplane crashed just after noon into a wooded area 100 feet north of the Montgomery County Air Park runway.

Hubert Franklin Jett, 53, of 7510 Brown Bridge Rd. in Highland probably died of massive internal injuries, said Dr. John Rogers, coroner for the west side of the county. Jett, who was alone in the plane, was pronounced dead at the crash site.

Police said Jett fueled his plane at the air park and took off but the engine apparently stalled and he tried to circle back to land. Witnesses told police they heard the engine sputter, saw the plane circle the field twice, then crash between two trees that ripped off its wings.

"The question we can't answer is why he didn't try to go down in the field instead of the woods ," said county police spokesman Phillip Caswell.

Jett's plane crashed only 50 yards from where Montgomery County's last fatal plane crash happened, in May 1983, when two men and an 8-year-old boy died after their small plane crashed in the field after takeoff.

Caswell said residents near the airport, in Gaithersburg, have complained to county officials about increasing traffic at the air park.

Jett had built the orange plane, decorated on the tail and wings with brown and white tattersall checks, from a Shoestring brand experimental model airplane kit in 1976, according to police. Caswell said Jett was a member of an aviation club that makes the light, single-engine Shoestrings.

National Transportation Safety Board officials are investigating what caused the crash.

Baltimore medical examiners also will perform an autopsy to determine the exact cause of death, Caswell said.