What happened
On November 22, 2021, a Beechcraft 200 (registration PS-HCS), operated by Brasil Vida Táxi Aéreo Ltda., departed from Aeródromo Atlas Brasil Cantanhede (SBBV) in Boa Vista, RR, bound for Palmas, TO. The aircraft was performing an aeromedical transport mission with four crew members and two passengers on board.
Shortly after takeoff, the crew noticed that the landing gear transit light remained illuminated after the gear lever was moved to the up position. The crew decided to return to the departure airfield. During the landing attempt, the left main landing gear retracted upon touchdown. All 6 occupants escaped the incident without injuries, though the aircraft sustained light damage.
The investigation
CENIPA investigators examined the aircraft's landing gear system, which utilizes a mechanical extension and retraction system powered by a 28 VDC electric motor, with a manual hydraulic pump available for emergency use. The investigation focused on the nose landing gear actuator, which showed irregular wear and fractures on the first thread of the internal screw axis.
Analysis suggested that the internal threads had suffered compression damage, likely caused by a misalignment during a previous maintenance procedure. The investigation also noted that the operator was unable to provide maintenance records prior to the aircraft's nationalization, which prevented a deeper analysis of the component's full maintenance history. The investigation also found that the electric motor's circuit breaker had tripped during the event.
Findings
- Maintenance issues related to the improper alignment of the actuator components during assembly or repair.
- Inadequate management supervision regarding the oversight of technical maintenance activities and the control of maintenance documentation.
- The mechanical resistance caused by the damaged nose gear actuator likely impacted the entire integrated landing gear assembly, preventing the left main gear from achieving a locked-down position.