What happened
On November 9, 2002, an Aeroboero AB-115 aircraft, registered as PP-FGU and operated by the Aeroclube de Macaé, departed from Macaé Airport in Rio de Janeiro. The flight was a ferry mission intended to transport the aircraft to Conselheiro Lafaiete, Minas Gerais, for its annual inspection, with an intermediate stop planned in Juiz de Fora for refueling. Two crew members were on board: a commercial pilot and instructor with 458 total hours, and a student pilot with 19 total hours.
The aircraft took off at 15:00 local time after a previous attempt was aborted due to unfavorable weather. Approximately 44 minutes into the flight, while cruising at 6,500 feet near Friburgo, Rio de Janeiro, the engine produced a loud friction noise and vibration, followed by a loss of power. The instructor took control and attempted an emergency landing on the Teresópolis–Friburgo highway. However, due to excessive altitude and speed, the aircraft collided with medium-voltage power lines and trees before crashing at the base of a nearby mountain. Both crew members exited the wreckage unharmed.
The investigation
CENIPA investigators determined that the engine failure was caused by the ignition plug on cylinder number 3 becoming detached in flight. An inspection revealed that an inappropriate brass adapter had been used to connect the spark plug, which failed under high temperatures. This modification was not specified in the aircraft manual and was not recorded in the engine logbook. The maintenance was performed without proper supervision, reflecting a culture of informality within the Aeroclube de Macaé.
Findings
The primary causal factor was improper maintenance involving an unauthorized brass adapter on the ignition system. Contributing factors included inadequate supervision by the aeroclube, insufficient emergency procedure training for the instructor, and poor organizational management structures that allowed unmonitored maintenance work.
Safety action
CENIPA issued several operational safety recommendations to the Aeroclube de Macaé and regional aviation authorities. These included conducting a special safety inspection of the club, restructuring its organization to establish distinct personnel, operations, maintenance, and safety departments, hiring qualified staff for exclusive roles, implementing quarterly emergency traffic training for pilots, and enforcing stricter supervision protocols for maintenance activities.