AD 97-16-02 Airworthiness Directives; Robinson Helicopter Company Model R44 Helicopters

Makes named: robinson. Models named: R44. Read the applicability below — it usually turns on serial or part numbers too.

Model R44 helicopters, serial numbers 0001 through 0332, certificated in any category. Note 1: This AD applies to each helicopter identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For helicopters that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must use the authority provided in paragraph (d) to request approval from the FAA. This approval may address either no action, if the current configuration eliminates the unsafe condition, or different actions necessary to address the unsafe condition described in this AD. Such a request should include an assessment of the effect of the changed configuration on the unsafe condition addressed by this AD. In no case does the presence of any modification, alteration, or repair remove any helicopter from the applicability of this AD.

Required as indicated, unless accomplished previously. To prevent failure of the sprag clutch to lock in the driving direction, which would result in loss of power to the main rotor system and a subsequent forced landing; or failure of the sprag clutch to unlock in the overrunning direction, which, if combined with engine failure, would result in an inability to autorotate and a subsequent loss of control of the helicopter, accomplish the following: (a) Within 25 hours time-in-service (TIS) after the effective date of this AD, and thereafter, at intervals not to exceed 100 hours TIS, inspect both up-limit switches, part number (P/N) V3- 1001, for proper operation in accordance with the Compliance Procedure in Robinson Helicopter Company R44 Service Bulletin SB-21, dated April 18, 1997. If the motor runs when the springs are depressed on one side, the switch on the OPPOSITE side is not functioning properly. (b) If the inspections required by paragraph (a) of this AD indicate that either up-limit switch does not function properly, replace the up-limit switch with an airworthy up-limit switch in accordance with the Compliance Procedure contained in Robinson Helicopter Company R44 Service Bulletin SB-21, dated April 18, 1997. (c) Within 50 hours TIS after the effective date of this AD, replace the clutch assembly, P/N C018-1, with a clutch assembly, P/N C018-2 or P/N C018-2A, in accordance with the Compliance Procedure contained in Robinson Helicopter Company R44 Service Bulletin SB-23, dated May 30, 1997. (d) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Los Angeles Aircraft Certification Office, FAA. Operators shall submit their requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Los Angeles Aircraft Certification Office. Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Los Angeles Aircraft Certification Office. (e) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the helicopter to a location where the requirements of this AD can be accomplished. (f) The inspections and replacements, if necessary, shall be done in accordance with Robinson Helicopter Company R44 Service Bulletin SB-21, dated April 18, 1997, and Robinson Helicopter Company R-44 Service Bulletin SB-23, dated May 30, 1997. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Robinson Helicopter Company, 2901 Airport Drive, Torrance, California 90505, telephone (310) 539-0508, fax (310) 539-5198. Copies may be inspected at the FAA, Office of the Assistant Chief Counsel, 2601 Meacham Blvd., Room 663, Fort Worth, Texas; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. (g) This amendment becomes effective on August 18, 1997. Issued in Fort Worth, Texas, on July 22, 1997. Mark R. Schilling, Acting Manager, Rotercraft Directorate, Aircraft Certification Service. [FR Doc. 97-20195 Filed 7-31-97; 8:45 am] BILLING CODE 4910-13-U