What happened
On September 22, 2002, an Aero Boero AB-115, registration PP-GND, was performing a local flight near Fazenda Tupã, Mato Grosso. The aircraft had previously flown from Jaciara to the farm area because the local municipal aerodrome was closed for construction. After a period of flight, a passenger replaced a student pilot for the local flight mission. Shortly after takeoff, the aircraft lost altitude and struck the ground in a nose-down attitude, approximately three kilometers from the runway threshold. The impact was severe, and both the pilot and the passenger sustained fatal injuries.
The investigation
CENIPA's investigation focused on the aircraft's performance and the circumstances leading to the loss of control. Investigators examined the engine, finding that at the moment of impact, the engine was producing little to no power. While there was no evidence of a sudden mechanical seizure, the investigation identified several irregularities in the engine's condition, including excessive oil consumption due to worn piston rings, insufficient lubrication affecting the hydraulic lifters, and excessive lead deposits on the spark plugs. Additionally, the investigation looked into the pilot's flight authorization and the possibility of improper fuel use.
Findings
- The primary cause of the accident was the use of a speed below the minimum glide speed, which led to a loss of lift (stall) and a subsequent spin at an altitude too low for recovery.
- The aircraft's engine was operating with degraded performance due to internal wear and lubrication issues.
- The pilot was performing an unauthorized flight, as the flight had not been approved by the aeroclub management.
- There was a lack of organizational oversight at the aeroclub, which failed to implement a system to monitor and control flights performed by instructors.
- The investigation noted the possibility that the pilot may have failed to visually verify fuel levels during the pre-flight inspection, potentially contributing to engine power loss.