ALVA, Okla. (AP) — Authorities in northwestern Oklahoma say a 61-year-old flight instructor is dead following the crash of a single-engine aircraft in Woods County.

The Oklahoma Highway Patrol says the crash occurred about 5:30 p.m. Saturday as the aircraft was approaching the Alva Municipal Airport. Troopers say a preliminary investigation indicates the aircraft experienced a mechanical failure during descent and that its landing gear struck some power lines. Authorities say the small aircraft struck some trees, plummeted to the ground and burst into flames.

Officials say the instructor, David Chael of Enid, was pronounced dead at the scene. A flight school student, 39-year-old Cory Washburn of Alva, was transported to a local hospital with undetermined injuries.

The Federal Aviation Administration and the National Transportation Safety Board are investigating the cause of the crash.