AD 96-06-02 61 FR 11536

This amendment supersedes an existing airworthiness directive (AD), applicable to The Enstrom Helicopter Corporation Model (Enstrom) F-28A, F-28C, 280, and 280C helicopters, that currently requires an initial and repetitive visual inspections of the upper swashplate bearings for corrosion, and replacement of defective upper swashplate bearings with airworthy bearings. This amendment requires that the visual inspections apply to both the upper and lower swashplate bearings (bearings); expands the applicability to include the Model F- 28C-2 helicopter; limits the applicability to those affected helicopters manufactured prior to January 1, 1981; establishes a retirement life of 1,200 hours time-in-service for certain bearings; and provides a corrected upper swashplate bearing part number. This amendment is prompted by the necessity to require visual inspections of the lower swashplate bearings; to expand the applicability to include the Model F-28C-2 helicopter; to establish a retirement life for certain bearings; and to correct the upper swashplate bearing part number from the existing AD. The actions specified by this AD are intended to prevent failure of the bearings and subsequent loss of control of the helicopter.