What happened
On December 31, 2015, a Raytheon B3-6TC, registration ZP-BIL, was attempting to depart from Costa Esmeralda Aerodrome (SDEN) in Porto Belo, Brazil, bound for Navegantes. The flight was planned as a visual flight rules (VFR) operation with two crew members on board.
The takeoff sequence involved three separate attempts. During the first attempt from runway 32, the aircraft experienced engine performance degradation after rotation, leading the crew to execute an aborted takeoff. This resulted in the aircraft exiting the right side of the runway, though no damage occurred. A second attempt was made using runway 14, which was aborted while the aircraft was still on the ground.
During the third attempt, again using runway 32, the engine performance degraded following rotation. The pilot attempted to land on the runway near the opposite threshold. The aircraft struck the ground with significant force, causing the landing gear to collapse and the aircraft to veer off the right side of the runway. The impact resulted in substantial damage to the engine, propeller, wings, landing gear, and fuselage. Both crew members were unharmed.
The investigation
CENIPA investigators gathered information regarding the aircraft's recent history and maintenance. Reports indicated that the pilot had noticed unusual engine noises during a previous flight, noting that the propeller pitch had been adjusted approximately five times to compensate for power loss during a flight from Curitiba to Santa Catarina prior to the accident. Additionally, during refueling in Santa Catarina, approximately 500ml of water and debris were removed from the fuel tanks.
The investigation faced significant obstacles regarding the technical analysis of the engine. While the engine and propeller were initially collected for testing, investigators were unable to contact the aircraft owner despite efforts involving aviation authorities in Paraguay and Argentina. The owner eventually contacted CENIPA via email, stating they could not attend the engine teardown due to health reasons and could not cover the costs of reassembling the components. Consequently, the engine was returned to the owner without undergoing the necessary examinations, preventing a definitive determination of the technical cause.
Findings
- The aircraft experienced engine performance degradation during the third takeoff attempt.
- The aircraft had previously exhibited abnormal engine behavior and power loss on preceding flights.
- Contaminated fuel (water and debris) was identified during a recent refueling.
- The investigation could not definitively establish the technical cause due to the inability to perform a teardown of the engine.