What happened
On 22 September 2009, a Schweizer 269C-1, registration G-LINX, was involved in an accident on the east bank of the River Wyre, near Stalmine, Lancashire. The incident occurred at approximately 11:03 UTC.
The investigation
The AAIB investigation examined the maintenance protocols applied to the aircraft, specifically focusing on the engine idle rpm and idle mixture settings. Investigators reviewed the Light Aircraft Maintenance Programme (LAMP) applicable to G-LINLE, which serves as the standard maintenance framework for such aircraft.
It was established that the generic LAMP did not include specific instructions for checking the engine idle rpm or the idle mixture. While the Aircraft Flight Manual provides operational parameters, the investigation looked into how maintenance requirements are updated and customized for specific airframes.
Findings
- The existing LAMP lacked specific requirements for the inspection of engine idle rpm and idle mixture.
- The failure to include specific engine idle rpm and mixture checks within the customized maintenance programme was a key factor identified in the context of ongoing airworthiness.
- The CAA provides reminders to operators regarding the necessity of customizing generic maintenance programmes via AIRCOM publications to address specific aircraft needs.