AD 79-21-04 ACTIVE

79-21-04 SOCIETE NATIONALE INDUSTRIELLE AEROSPATIALE (SNIAS): Amendment 39-3584. Applies to Model SA 330F Puma helicopters, certificated in all categories.

Compliance is required as indicated, unless already accomplished.

(a) To detect tail boom cracks and prevent excessive tail deflection, accomplish the following on helicopters that do not incorporate SNIAS Modification AMS 07.11.464 or SA 330 Service Bulletin No. 53.09:

(1) Within the next 50 hours time in service after the effective date of this AD and, thereafter, at intervals not to exceed 50 hours time in service since the previous inspection, inspect the tail boom structure at frame 12349 beneath the intermediate gear box forward attachment and at location of anchor nuts for cracks in accordance with Puma SA 330 Service Bulletin No. 05.30, dated March 8, 1973, or an FAA-approved equivalent.

(2) If during an inspection required by paragraph (a)(1) of this AD, only one crack that does not break through the doubler is found, continue to inspect in accordance with paragraph (a)(1) of this AD at intervals not to exceed 25 hours time in service since the previous inspection until incorporation of SA 330 Service Bulletin No. 53.09, dated March 8, 1973, or an FAA-approved equivalent.

(3) If during an inspection required by paragraph (a)(1) or (a)(2) of this AD, any crack is found extending to the end of the doubler, P/N 330F.24.2019.21, or into its flange, or more than one crack is found, immediately replace the doubler, P/N 330A.24.2019.21 in accordance with Puma SA 330 Service Bulletin No. 53.09, dated March 8, 1973, or an FAA-approved equivalent.

(b) To detect tail pylon cracks and prevent excessive tail deflection, accomplish the following on helicopters that incorporate SNIAS Modification 07.11.141/S256 or that are fitted with a tail skid without a reinforcement plate under the tail skid attachment fitting:

(1) Within the next 50 hours time in service after the effective date of this AD and, thereafter, at intervals not to exceed 50 hours time in service since the previous inspection, inspect the tail pylon structure for cracks and loose rivets in accordance with Puma SA 330 Service Bulletin 05.33, dated August 1, 1973, or an FAA-approved equivalent.

(2) If during any inspection required by paragraph (b)(1) of this AD, a defect described in subparagraphs (1) or (2) of paragraph 1.D. of Puma SA 330 Service Bulletin 05.33, dated August 1, 1973, or an FAA-approved equivalent, is found, and that defect does not exceed the limits noted in the subparagraphs (1) or (2), repeat the inspections required in paragraph (b)(1) of this AD at intervals not to exceed 25 hours time in service since the last inspection.

(3) If during any inspection required by paragraph (b)(1) or (b)(2) of this AD, a defect is found to equal or exceed the limits noted in subparagraphs (1) or (2) of paragraph 1.D. of Puma SA 330 Service Bulletin No. 05.33, dated August 1,1973, or an FAA-approved equivalent, within the next 25 hours time in service, reinforce the tail structure in accordance with Puma SA 330 Service Bulletin No. 53.12, dated October 24, 1973, or an FAA-approved equivalent.

(4) If during an inspection required by paragraph (b)(1) or (b)(2), a defect is found that is not specified in subparagraphs (1) and (2) of paragraph 1.D of Puma SA 330 Service Bulletin No. 05.33, dated August 1, 1973, or an FAA-approved equivalent, within the next 25 hours time in service after finding the defect, repair the defect in accordance with the Puma Structural Repair Manual, or an FAA-approved equivalent.

(c) For purposes of this AD, an FAA-approved equivalent must be approved by Chief, Aircraft Certification Staff, AEU-100, FAA, Europe, Africa, and Middle East Region, c/o American Embassy, Brussels, Belgium, Telephone: 513.38.30.

This amendment becomes effective November 1, 1979.