What happened
On the morning of August 31, 2002, a private BEECH A36, registered ZS-JPJ, departed George Aerodrome (FAGG) bound for New Tempe (FATP). The flight was conducted under Visual Flight Rules (VFR) with a single occupant. After taking off from Runway 29 and climbing to flight level 070, the pilot began a turn toward the Outeniqua Mountains. During the climb through 4,000 feet, the pilot noticed slight fluctuations in engine RPM. Efforts to stabilize the engine led to a rapid deterioration of performance, prompting an immediate decision to return to George.
As the aircraft approached the aerodrome, the pilot managed the manifold pressure and RPM to maintain engine effectiveness while flying over a populated area. While positioned on the left downwind leg, a loud bang occurred within the engine compartment, accompanied by smoke emerging from the cowling. To maintain visual contact with the airfield, the pilot utilized a side-slip maneuver. Fearing a potential landing gear malfunction, the pilot extended the gear early. Despite a higher sink rate, the pilot successfully completed a steep descent and landing. During the rollout, the pilot retracted the flaps and allowed the aircraft's momentum to carry it off the runway without applying brakes.
The investigation
The investigation focused on the mechanical failure that occurred during the climb and the subsequent engine behavior during the approach. Investigators examined the engine's performance fluctuations and the physical evidence of the loud bang and smoke reported by the pilot. The inquiry established that the engine's internal components had suffered significant damage.
Findings
- The aircraft suffered a loss of engine power caused by engine detonation.
- This detonation led to an engine seizure.
- The damage included a hole in the piston dome, which allowed oil to be burnt and expelled, resulting in the black smoke observed by the pilot.