What happened
Following the initial investigation into the accident involving the ZK-FMO, the pilot-in-command provided additional details for the Commission's consideration. This supplementary information addressed several technical and operational aspects of the flight, including the configuration of the aircraft's flaps and the specific distribution of weight within the cabin. The pilot also provided context regarding the interpretation of the company's load sheet instructions and the timing of updates made to the operator's manual.
The investigation
An independent review was conducted by a Commission Assessor and a Senior Inspector of Air Accidents who had no prior involvement in the original inquiry. This review focused on technical data concerning the engine's dual magneto system, specifically looking at the impact of a misaligned contact breaker assembly arm. The investigators also examined how the pilot's use of specific flap settings and load distributions might have influenced the aircraft's performance during the critical phases of departure.
Findings
While the fundamental causal factors identified in the original report remained largely unchanged, the review established a new technical nuance regarding engine output. The investigation found that a reduction in engine power during the takeoff and initial climb may have occurred. This loss of thrust likely depleted the already narrow performance margins of the aircraft, making the accident unavoidable under the existing conditions.