Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Fokker Model F27 series airplanes. This proposal would require increasing the torque value of the bolt that connects the gearbox housing assembly of the steering unit to the pivot bracket of the nose landing gear (NLG). This proposal would also require that periodic inspections of that torque value be incorporated into the FAA-approved maintenance program. This proposal is prompted by several reports that the dowel pins in the Walter Kidde nose wheel steering system were found broken and/or had elongated holes due to a reduced torque value of the subject bolt. The actions specified by the proposed AD are intended to prevent such a reduction in the torque value, which could result in failure of the dowel pins in the Walter Kidde nose wheel steering system; this situation could result in reduced controllability of the airplane or the collapse of the NLG during landing.