What happened
On January 11, 2012, a Piper PA-34-220T, registration PR-JMR, departed from Marabá Airport (SBMA) for Carajás, Brazil, carrying a pilot and four passengers. Shortly after takeoff, the pilot attempted to retract the landing gear, but the gear failed to retract, with the cockpit indicators showing the gear remained down and locked.
Deciding to return to Marabá, the pilot performed a landing attempt. Upon touchdown, the right landing gear began to retract, causing the right wing to drop lower than the left. The pilot immediately attempted a go-around, but the movement caused the right propeller blades to strike the runway surface. Following the impact, the pilot successfully cycled the landing gear, which then functioned correctly, allowing for a second, safe landing. All five occupants escaped without injury, though the aircraft sustained light damage.
The investigation
CENIPA investigators examined the aircraft's maintenance history and the circumstances of the flight. It was discovered that a week prior, the aircraft had experienced a similar failure to retract the gear. At that time, the pilot had performed self-directed testing of the gear system while the aircraft was supported by hydraulic jacks at a maintenance hangar. This testing was conducted by the pilot with the assistance of a mechanic who was not properly certified for this specific aircraft model. No formal service order was opened, and the pilot personally cleared the aircraft for return to service.
Subsequent technical analysis by a certified maintenance facility revealed that the right landing gear actuator was unable to maintain pressure and that hydraulic oil was leaking through the seals. Investigators suggested that the rubber seals may have deteriorated due to the aircraft's low utilization rate, as it had flown fewer than 100 hours per year since its manufacture in 2005.
Findings
- The aircraft was operating outside of its operational envelope, as it was approximately 200kg above its maximum allowable landing weight (weighing 2,249kg against a limit of 2,047kg).
- The primary cause of the gear collapse was the excessive weight of the aircraft, which triggered the retraction of the right gear upon touchdown.
- Inadequate maintenance oversight occurred when the pilot released the aircraft for service following a previous gear malfunction without a certified inspection.
- Flight discipline was noted as a factor, as the pilot failed to declare an emergency or request ground support services from Marabá Radio during the approach.
- Inadequate flight planning and management supervision contributed to the aircraft being operated in an overweight condition.