Accident Overview
A flight instructor (CFI) and a private pilot receiving dual instruction were conducting touch-and-go landings on Runway 17R. After the fourth landing, power was applied and a normal climb began. At approximately 400 feet above ground level (AGL), power was reduced, and the engine developed heavy vibrations accompanied by an estimated 50% power loss.
The CFI took control from the private pilot. Initially turning right, the CFI then executed a left downwind turn. With the aircraft at a 45- to 60-degree angle of bank, it turned approximately 190 degrees in an effort to land on Runway 35L. According to the CFI, the aircraft stalled and contacted the ground left wing first.
Engine Examination
Post-accident examination of the engine revealed that continuity in the mixture control system did not exist. Investigators found no attaching hardware that would connect the mixture linkage to the carburetor. This missing hardware had not been installed by the operator, and the aircraft had accumulated 13.8 flight hours in the 35 days prior to the accident since the last maintenance action that would have involved the mixture control.
After re-rigging the mixture control linkage and repairing impact damage sustained during the accident, the engine was successfully test-run, confirming the absence of any pre-impact mechanical failure beyond the linkage issue.
Environmental Conditions
At the time of the forced landing, the wind was reported as from 180 degrees at 18 knots, gusting to 28 knots.
Probable Cause
Loss of engine power due to the absence of hardware connecting the mixture control linkage to the carburetor, which resulted in a loss of continuity in the mixture control system.