What happened
On August 5, 2008, a Beechcraft F3-3A, registration PT-WJQ, was performing a flight from Bom Jesus da Lapa to Boquira, Bahia. The aircraft was cruising at 5,500 feet when the engine suddenly lost power while overflying the Mangabeira mountain range. The pilot, experiencing severe turbulence, attempted to restart the engine without success.
To avoid the mountainous terrain, the pilot executed an emergency landing in a pasture approximately 30 meters from the threshold of runway 03 at the Boquira aerodrome. During the landing, the aircraft struck the ground with the landing gear extended, skidded approximately 10 meters, and eventually came to rest in a depression in the terrain. The impact caused severe damage to the fuselage, wings, propeller, and engine.
The investigation
CENIPA investigators examined the aircraft's maintenance history and the pilot's operational background. The investigation confirmed that the aircraft's airworthiness certificate was valid and that the last 50-hour inspection had been completed recently. The engine itself showed no signs of mechanical failure, such as fuel or oil leaks, and inspections of the fuel pump, spark plugs, and ignition cables revealed no abnormalities.
Investigators also analyzed the meteorological conditions, noting that while visibility was good, the flight was subject to heavy turbulence caused by strong winds over the mountain range. The investigation also looked into the pilot's experience, noting that while the pilot held a valid private pilot license, they had been flying this specific aircraft type for less than a year and lacked formal operational supervision because they were also the aircraft's owner.
Findings
- Inadequate flight planning, as the pilot prioritized flight distance over the analysis of topography and prevailing meteorological conditions.
- Improper decision-making regarding the decision to continue the flight despite encountering severe turbulence.
- Lack of operational supervision due to the pilot being the owner-operator, which prevented the identification and correction of latent performance deficiencies.
- Overconfidence in the pilot's ability to manage the flight despite limited experience in the aircraft type and the challenging terrain.
- The possibility that the engine failure was caused by the inadvertent movement of the fuel selector valve during the heavy turbulence.