Airworthiness Directive · Amendment 39-9539 · Enstrom Helicopter Corporation, The Helicopters
Enstrom Helicopter Corporation, The Helicopters
This AD applies to Enstrom Helicopter Corporation, The 280, 280C, F-28A, F-28C, F-28C-2.
The models as the FAA's AD index lists them. The serial ranges, installed parts and exceptions are in the AD itself: read it at the FAA.
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.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
