What happened
On March 4, 2024, at 10:55 LMT, a Piper Pa-44 180T, registration SP-MIS, was performing a landing approach at EPMO when the crew noticed that the nose gear extension indicator failed to signal that the gear was down. The pilot attempted to retract and re-extend the gear, but the indication remained unchanged. After notifying EPMO Tower, the crew performed a low pass over the runway, during which air traffic controllers visually confirmed that the nose gear had not locked down.
The crew proceeded to a holding area to troubleshoot the issue. After numerous unsuccessful attempts to extend the gear, the crew initiated an emergency gear release procedure; however, this also failed to lock the nose gear in the extended position. The crew then proceeded to burn off excess fuel while continuing attempts to manipulate the gear. During these maneuvers, the hydraulic pump briefly ceased operation before resuming normal function. A subsequent attempt to extend and lock the gear was successful. Following a visual confirmation by an observer during a runway pass, the crew landed safely on runway 08 at EPM0 without further incident.
The investigation
The investigation focused on the mechanical state of the landing gear system and the effectiveness of the emergency release procedure. The investigation established that the mechanical failure was rooted in internal resistance within the gear mechanism.
Findings
- The primary cause of the incident was a mechanical failure of the nose gear extension and retraction system.
- The failure was driven by abnormal friction within the mechanism, a mechanical blockage, and contamination of the mechanism's bearings.
Safety action
The following corrective maintenance was performed on the aircraft:
- The nose gear retraction mechanism was removed and thoroughly cleaned.
- New bearings, bushings, and bolts were installed.
- The nose wheel rocker spring components were replaced with new parts.
- All bushings and the retraction mechanism were re-lubricated.
- The nose gear extension and retraction indicator switches were readjusted.
- The lower nose gear mounting bushing was re-regulated.