Accident
On 28 September 1999 at 1034 UTC, a Piper PA-46 Malibu, registration N666LP, was involved in an incident at Southampton Airport, Hampshire. The occurrence was reported by the pilot and investigated by the AAIB. The aircraft sustained a fatigue-induced fracture in the area of the engine/nose landing gear mounting frame.
Maintenance Inspection
The AAIB noted that there were no required specific inspections for this area of the mounting frame. However, the manufacturer drew attention to the 100-hour check of the jack actuator and attachment nuts for condition and security, as included in Item 21 of Section E (Landing Gear Group) of the Periodic Inspection Chart (AMM page 1C19). This inspection also requires a retraction and extension check of the landing gear system. Additionally, the manufacturer referred to Chart 1, 'Trouble Shooting Nose Gear' (AMM page 3D11), which requires that if the nose gear fails to steer correctly, the cause should be determined and corrected.
Findings
The mounting frame is not routinely removed in service, and the fractured area is difficult to inspect visually. It is also an area frequently dirty from operation. While such a crack propagates, it may 'open up' causing steering difficulties, then 'close up' restoring normal steering, reducing visual indications. The manufacturer stated that this was the only instance of such cracking in that part of the mounting frame of which they were aware, and considered it an isolated incident. Consequently, no safety recommendation was made. The AAIB indicated that when steering problems are encountered, the source should be positively identified, with attention to possible cracking in related areas requiring thorough cleaning to improve visual inspection effectiveness.