78-08-08 BELL: Amendment 39-3189. Applies to Bell Models 214B and 214B-1 helicopters, S/N 28001 through 28024 and S/N 28032 through 28036, certificated in all categories.
Compliance required as indicated.
To detect possible cracks in the tail fin forward spar, to improve the strength and fatigue resistance of the tail fin and boom and to preclude possible failure of the fin, accomplish the following repetitive inspection and modification.
(a) Before the first flight of each day after the effective date of this AD, conduct the following inspection of the tail fin forward spar, left side cap angle, and the spar web until the modification in paragraph (b) is accomplished:
(1) Remove the 42 degree gear box cover from the tail boom.
(2) Remove the paint finish and clean the spar left side cap angle and left forward side of the spar web in the area surrounding the rivets where the fin intersects the tail boom, using a cloth and methyl-ethyl ketone or equivalent.(3) Inspect the cap angle and web in the clear area of the spar for cracks using a three-power or higher magnifying glass and a light, or a dye penetrant or equivalent inspection method.
(4) If no cracks are found, install the gear box cover.
(5) If cracks are found, remove the tail boom before further flight and replace with a tail boom and fin modified in accordance with the data specified in paragraph (b) of this AD.
(b) On or before July 30, 1978, modify the tail boom and fin in accordance with Bell Helicopter Textron Drawing No. 214-961-151 or in accordance with an equivalent means approved by the Chief, Engineering and Manufacturing Branch, Federal Aviation Administration, Southwest Region.
(c) The manufacturer's instructions identified and described in this directive are incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). All persons affected by this directive who have not already received these documents from the manufacturer may obtain copies upon request to the Service Manager, Bell Helicopter Textron, P.O. Box 482, Fort Worth, Texas 76101. These documents may also be examined at the Office of the Regional Counsel, Southwest Region, FAA, 4400 Blue Mound Road, Fort Worth, Texas, and at FAA Headquarters, 800 Independence Avenue, S.W., Washington, D.C. A historical file on this AD which includes the incorporated material in full is maintained by the FAA at its headquarters in Washington, D.C., and at the Southwest Regional Office in Fort Worth, Texas.
(Bell Helicopter Textron Service Bulletin No. 214-77-8 pertains to inspections and Service Bulletin No. 214-78-1 pertains to modifications.)
This amendment becomes effective April 21, 1978.