89-23-14: Main Rotor Collective Tubes

89-23-14 MCDONNELL DOUGLAS HELICOPTER COMPANY (MDHC): Amendment 39-6392. Docket No. 89-ASW-26. Applicability: Model 369 series helicopters, certificated in any category, with main rotor collective tube, P/N 369A7009-BSC; longitudinal control tube, P/N 369A7011-BSC; lateral control tube, P/N 369A7012-BSC; and tail rotor control tube, P/N 369A7007-BSC. Compliance: Required as indicated, unless already accomplished. To prevent fatigue failure of the control tubes which could result in loss of control of the helicopter, accomplish the following: (a) Within 25 hours' time in service after the effective date of this AD, and at intervals of 100 hours' time in service until the requirements of paragraph (c) are accomplished, remove and inspect for cracks the swaged ends of each main rotor collective control tube (P/N 369A7009-BSC), longitudinal control tube (P/N 369A7011-BSC), lateral control tube (P/N 369A7012-BSC), and each tail rotor control tube (P/N 369A7007-BSC)installed on a helicopter. If external cracks are observed as a result of this inspection, replace the control tube with a serviceable unit prior to further flight. NOTE: PART I of MDHC Service Information Notice DN-158.1, EN-48.1, FN-36.1, and HN-217.1 pertains to this AD. (b) Prior to installation, inspect for cracks the swaged ends of each main rotor collective control tube (P/N 369A7009-BSC), longitudinal control tube (P/N 369A7011-BSC), lateral control tube (P/N 369A7012-BSC), and tail rotor control tube (P/N 369A7007-BSC) from spares inventory. Reject control tubes found to be cracked as a result of this inspection. (c) Within 600 hours' time in service after the effective date of this AD remove and inspect each main rotor collective control tube (P/N 369A7009-BSC), longitudinal control tube (P/N 369A7011-BSC), lateral control tube (P/N 369A7012-BSC), and tail rotor control tube (P/N 369A7007-BSC) in accordance with the requirements of paragraph (a). Replace cracked tubes with BASIC (BSC) part numbers with the corresponding FAA-approved -5 configuration. Modify remaining BASIC (BSC) tubes to the corresponding FAA-approved -5 configuration before reinstallation. NOTE: PART II of MDHC Service Information Notice DN-158, EN-48, FN-36 or HN- 217 pertains to rework and reinstallation procedures. (d) In accordance with FAR Sections 21.197 and 21.199, the helicopter may be flown to a base where compliance with the AD may be accomplished. (e) An alternate method of compliance with this AD which provides an equivalent level of safety may be used if approved by the Manager, Los Angeles Aircraft Certification Office, FAA, 3229 E. Spring Street, Long Beach, California. This amendment (39-6392, AD 89-23-14) becomes effective on December 4, 1989.