What happened
On 28 September 1999, a Piper PA-46 Malibu, registration N666LP, was involved in an incident at Southampton Airport, Hampshire. The event involved issues related to the aircraft's nose gear steering capabilities.
The investigation
The AAIB examined the condition of the nose gear assembly and the mounting frame. The investigation established that a fatigue-induced fracture had occurred within the engine/noseleg mounting frame.
Investigators noted that the specific area where the fracture occurred is not subject to any mandatory specific inspections under current maintenance protocols. While the manufacturer's maintenance manual includes a 100-hour check for the jack actuator and attachment nuts, the mounting frame itself is not routinely removed during standard service.
Furthermore, the investigation found that the area is prone to accumulating dirt during operation, which can obscure visual inspections. A significant challenge identified was the nature of the crack propagation; the fracture could potentially open and close as the frame deflected. This movement could cause intermittent steering difficulties followed by a period where the steering appears normal, effectively hiding the visual evidence of the crack.
Findings
- A fatigue-induced fracture was present in the nose gear mounting frame.
- The difficulty of performing effective visual inspections due to the area's location and the accumulation of operational grime.
- The potential for the crack to intermittently close, masking its presence during routine checks.
- The manufacturer considers this an isolated incident, as no other similar cracking in this specific part of the frame has been reported.