What happened
On May 11, 2004, a Piper J3F-65, registration PP-GQN, was conducting a navigation training flight as part of a Commercial Pilot course. The flight departed from Joinville, SC, with an instructor and a student on board. During the flight, the engine experienced a power fluctuation followed by a total loss of power.
Following the initial power loss, the instructor took control and attempted to divert to Navegantes, SC. During this period, the engine produced a loud noise and intense vibrations, causing the aircraft to lose altitude. The crew decided to perform an emergency landing in a rural area near Penha, SC, specifically targeting a field adjacent to a kart track. While attempting to maneuver around local power lines on the short final approach, the left wing of the aircraft struck a tree, subsequently impacting the ground.
The investigation
The CENIPA investigation focused on the mechanical failure and the circumstances leading to the impact. Technical analysis of the engine revealed that the intake valve rocker arm of cylinder number two had broken. The investigation noted that the engine had undergone an overhaul in 1998 but had remained in storage for approximately three years before being reinstalled in the aircraft in 2001. Investigators could not definitively determine if the storage conditions or the reinstallation process contributed to the component failure, but they noted that the failure was not a normal occurrence.
Regarding the impact, the investigation found that the instructor suffered serious injuries, while the student sustained light injuries. The aircraft sustained severe damage to the engine and landing gear. It was also noted that the lack of seatbelts/harnesses caused the instructor to be thrown forward, contributing to a serious cervical spine injury.
Findings
- The primary cause of the engine failure was the breakage of the intake valve rocker arm in cylinder number two.
- Inadequate engine maintenance or storage procedures likely contributed to the component failure.
- The crew's decision-making regarding the landing site was considered indeterminate, as the exact point of the engine failure could not be precisely located.
Safety action
- CENIPA recommended that ANAC disseminate the findings of this report to flying clubs and aviation schools, emphasizing the critical importance of proper aircraft maintenance.