AD 2001-20-18 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, with horizontal stabilizer assembly (assembly), part number (P/N) C044-1; horizontal stabilizer serial number (S/N) 0009 through 0224, except S/N 0018, 0090, 0094, 0111, 0129, 0144, 0161, 0178, 0201, and 0223, installed, certificated in any category. Note 1: This AD applies to each helicopter identified in the preceding applicability provision, regardless of whether it has been otherwise 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 request approval for an alternative method of compliance in accordance with paragraph (c) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Required as indicated, unless accomplished previously. To prevent a crack through a vertical-to-horizontal stabilizer attach channel (channel), which can cause separation of the stabilizers and subsequent loss of control of the helicopter, accomplish the following: (a) Before accumulating 2200 hours time-in-service (TIS) on the assembly: (1) Remove the vertical stabilizer to inspect the nutplate on channels, P/N D283-1 and -2. (2) If the nutplates are P/N MS21086L4, no further action is required by this AD. (3) If the nutplates are P/N NAS697A4, replace the channels with airworthy channels, P/N D296-1 or -2. Note 2: Robinson Helicopter Company Service Bulletin SB-39, dated September 12, 2000, pertains to the subject of this AD. (b) This AD revises the Limitations section of the maintenance manual by establishing a retirement life of 2200 hours TIS for assembly, P/N CO44-1, with channels, P/N D283-1 or -2, with nutplates, P/N NAS697A4, installed. (c) 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 (LAACO), FAA. Operators shall submit their requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, LAACO. Note 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the LAACO. (d) Special flight permits may be issued in accordance with 14 CFR 21.197 and 21.199 to operate the helicopter to a location where the requirements of this AD can be accomplished. (e) This amendment becomes effective on November 19, 2001. Issued in Fort Worth, Texas, on October 3, 2001. Mark R. Schilling, Acting Manager, Rotorcraft Directorate, Aircraft Certification Service. [FR Doc. 01-25693 Filed 10-12-01; 8:45 am] BILLING CODE 4910-13-P