On July 11, 1991, an Aeronca 11-AC (registration N86083) operated by Terrance A. Grahm was involved in an aviation accident near Central Lake, MI. Investigators recorded the probable cause as: A RESULT OF THE PILOT IN COMMAND NOT MAINTAINING AIRCRAFT CONTROL AND NOT PERFORMING REMEDIAL ACTION AFTER THE AIRPLANE ENTERED THE STEEP DESCENT. A FACTOR CONTRIBUTING TO THIS ACCIDENT WAS THE PILOT IN COMMAND'S LACK OF RECENT EXPERIENCE. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
After a touch and go landing, a light single-engine airplane pitched straight down and descended into terrain. Investigation found no mechanical issues; the airstrip had a 3-degree downslope and terrain beyond dropped into a 300-foot valley.
Accident Sequence
Witnesses observed the light, single-engine airplane performing a climb after a touch and go landing. During the climb, the airplane suddenly pitched straight down and descended into the terrain. An on-scene investigation did not reveal any control, airframe, or powerplant conditions that would contribute to such an uncontrolled descent.
Airstrip and Terrain
The airstrip had a 3-degree downslope from the center of the runway toward both the approach and departure ends. The terrain off the departure end of the runway drops suddenly into an approximately 300-foot deep valley.
Aircraft Inspection and Pilot Information
Investigation revealed the airplane's last annual inspection was 10 years prior to the accident. The pilot held a student pilot and third class medical certificate that was issued approximately 13 years prior to the accident. The pilot's last flight as pilot in command was approximately two years prior to the accident.