AD 78-21-04

78-21-04 SOCIETE NATIONALE INDUSTRIELLE AEROSPATIALE (SNIAS): Amendment 39-3319. Applies to Model SA 330 Puma helicopters, S/N 1504 and below, certificated in all categories, having yaw control bellcranks P/N 330A.77.4011.01 that have been modified in accordance with SNIAS Modification AMS 07.10.226 but not modified in accordance with AMS 07.11.890.

Compliance is required as indicated, unless already accomplished.

To prevent possible failure of the yaw control bellcrank, P/N 330A.77.4011.01, accomplish the following:

(a) Within the next 25 hours time in service after the effective date of this AD, or prior to the accumulation of 1200 hours total time in service, whichever occurs later, inspect the tubular section of the yaw control bellcrank P/N 330A.77.4011.01, for cracks in accordance with Puma SA 330 Service Bulletin No. 05.50, dated March 22, 1977, or an FAA-approved equivalent.

(b) If during any inspection required by this AD a cracked bellcrank is found,replace the bellcrank with a serviceable part of the same part number.

(c) After the initial inspection required by paragraph (a) of this AD, continue to inspect all yaw control bellcranks, and all replacements that have accumulated 1200 or more hours total time in service, in accordance with paragraph (a) of this AD after the last flight of each day in which the helicopter is operated.

(d) The repetitive inspections required by paragraph (c) of this AD may be discontinued upon the incorporation of a serviceable bellcrank, P/N 330A.77.4011.01, that has been modified in accordance with Puma SA 330 Service Bulletin No. 67.10, dated March 22, 1977, or an FAA-approved equivalent.

NOTE: The modification covered in Service Bulletin No. 67.10 corresponds to Puma Modification AMS 07.11.890.

This amendment becomes effective November 20, 1978.