AD 74-08-03

74-08-03 BELL: Amendment 39-1806. Applies to Bell Model 212 helicopters, S/N 30504 through 30593, certificated in all categories.

Compliance required as indicated.

To detect and prevent possible cracks in the tail fin forward spar cap angle and in the tail boom skin adjacent to the fin, accomplish the following repetitive inspections and modification.

(a) Within 25 hours time in service after the effective date of this A.D. and thereafter at intervals not to exceed 25 hours time in service from the last inspection, accomplish the following inspections until the modification of paragraph (b) is completed.

(1) Remove the 42 degree gear box cover from the tail boom.

(2) Remove the first rivet above the tail boom on the left side of the vertical fin forward spar cap angle. Remove the paint finish and clean the area around the rivet hole (inboard and outboard sides of the spar cap angle), using cloth and Methyl Ethyl Ketone or equivalent. Do not reinstall thefirst rivet.

(3) Inspect the rivet hole and clear area of the spar for cracks using a three power or higher magnifying glass or a dye penetrant or equivalent inspection method.

(4) If no cracks are found, protect the clear area of the spar and rivet hole using a clear lacquer or light film of clear grease or equivalent transparent protection and install the gear box cover.

(5) If cracks are found, remove the tail boom and replace with an uncracked tail boom in accordance with the procedures specified in the Bell Model 212 maintenance manual.

(b) Within 100 hours time in service after the effective date of this A.D., modify the tail fin and tail boom in accordance with Part III, Bell Helicopter Co., Service Bulletin No. 212- 01-73-1, Rev. B, dated October 9, 1973 or later FAA approved revision.

The manufacturer's specifications and procedures 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 Company, 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 A.D. 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.

This amendment becomes effective May 6, 1974.