Mandatory Service Bulletin Issued for all North American P-51 Mustangs

A serious safety issue has been uncovered for North American P-51 Mustangs and there has been a Mandatory Service Bulletin issued by Cal Pacific Airmotive, Inc. in cooperation with the National Transportation Safety Board (NTSB).

Failure of the elevator trim tab and loss of control of the aircraft has been experienced by a North American Aviation (NAA) P-51 aircraft. Contributing factors were worn fiber lock spline nuts at the elevator trim tab hinge attach fittings and the installation of non-structural screws and hardware. Inspection has found that several P-51 aircraft in service today still have the original manufacturer installed self-locking spline nuts, dating back more than 60 years. Spline nuts are a self-locking nut that is pressed into a fitting, and are used throughout the NAA P-51 aircraft.

Within the next 20 hours of operation or no later than May 1, 2013 and at each 100 hours of operation, or 12 months whichever occurs first, to prevent failure of aircraft control systems accomplish the following:

1. Inspect all phenolic trim tabs for condition and signs of deterioration or delamination of the trim tab. Replace any defective tab with a serviceable, approved phenolic or metal trim tab.
2. Inspect aircraft control systems for properly installed structural hardware and condition of self-locking nuts and spline nuts in accordance with Maintenance Manual.

The full bulletin is available HERE.