What happened
On May 8, 2006, a BE-V35B Bonanza, registration PT-KEZ, departed from the uncertified municipal aerodrome in Alto Araguaia, Mato Grosso, bound for Mineiros, Goiás. The flight was intended to transport three passengers under Visual Flight Rules (VFR).
Shortly after takeoff, while the landing gear was still extended, the aircraft entered a sharp left turn at a low altitude. Witnesses reported hearing an engine malfunction, followed by an explosion. The aircraft struck the ground in a steep nose-down attitude, causing the airframe to break apart and ignite. The impact and subsequent fire resulted in four fatalities, including the pilot and all three passengers.
The investigation
CENIPA investigators examined the wreckage and the aircraft's mechanical components. Analysis of the engine revealed that the mechanical fuel pump's shaft had sheared. Laboratory testing by the Aeronautical Institute of Space (IAE) identified foreign contaminants, including sodium chloride (NaCl) crystals, within the fuel pump.
Investigators also noted that the aircraft had been parked in an unsecured, open area for two days prior to the accident. The investigation explored several hypotheses for the engine failure, including fuel contamination from moisture ingress or potential fuel theft/replacement, as well as the possibility that the pilot failed to drain the fuel tanks during pre-flight preparations.
Findings
- The mechanical fuel pump failed due to the presence of foreign material and a sheared shaft.
- The pilot's inadequate management of the engine failure was a critical factor; instead of focusing on an emergency forced landing in a nearby unobstructed plowed field, the pilot's attention was diverted to troubleshooting the engine.
- The aircraft was operating from a non-homologated runway that had previously been subject to a NOTAM canceling operations.
- The aircraft had been left unattended in an open area without fuel tank security, increasing the risk of contamination or tampering.