What happened
On February 3, 1996, a Piper PA-20 (registration PP-GPO) departed from the Fazenda Macuco runway in Vassouras, Rio de Janeiro, to perform a skydiving mission. The aircraft was carrying the pilot and two skydivers. During the climb, upon reaching approximately 2,300 feet, smoke was observed emanating from the engine, followed by flames appearing below the instrument panel.
Recognizing the emergency, the pilot initiated a descent and ordered the skydivers to bail out. The passengers successfully exited the aircraft at approximately 800 feet. The aircraft, fully engulfed in flames, subsequently struck the ground approximately 1,000 meters from the runway and exploded upon impact. The pilot sustained fatal injuries, while one skydiver suffered first and second-degree burns.
The investigation
CENIPA investigators examined the wreckage and found evidence of fire at the rear of the engine, specifically near the firewall and the fuel strainer. The investigation revealed that the engine oil hose, although appearing new, had been deformed by extreme heat due to its proximity to the number 4 cylinder exhaust. Traces of oil were also found in the exhaust muffler.
Crucially, the investigation established that the oil hose had been replaced by the pilot on the day of the accident. The pilot had sourced a similar-looking hose from the inventory of a different aircraft type (an AB-115) because it appeared compatible. During the installation, the hose was positioned against the exhaust pipe, which led to its failure under operational temperatures.
Furthermore, the investigation looked into the pilot's credentials and the club's operational status. It was noted that the pilot was performing maintenance without the required qualifications and was operating the aircraft with expired technical and medical certifications. The Aeroclube de Nova Iguaçú was also facing significant financial difficulties at the time.
Findings
- Improper maintenance: The pilot performed an unauthorized repair using an inadequate oil hose that was not specified for the Piper PA-20.
- Mechanical failure: The incorrect hose placement allowed heat from the exhaust to deform the part, causing an oil leak that ignited the fuel strainer.
- Psychological factors: The pilot's high level of self-confidence and the pressure to maintain club operations led to a poor decision-making process and the disregard of safety standards.
- Operational deficiencies: The pilot acted as both the operator and the supervisor, failing to utilize professional maintenance services and operating with expired flight and medical credentials.