AD 98-04-12 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 0002 through 0420, 0425, 0426, and 0427, with a C056-1 Rev. A through G spring assembly 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 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 detect excessive wear on the lateral cyclic trim spring shaft (shaft), which could allow the shaft to move from its lower mount and interfere with lateral cyclic control resulting in loss of control of the helicopter, accomplish the following: (a) Within 10 hours time-in-service (TIS), and thereafter at intervals not to exceed 20 hours TIS, measure the diameter of the shaft in accordance with the Compliance Procedure contained in Robinson Helicopter Company R44 Service Bulletin SB-26, dated January 31, 1998 (SB-26). (b) If the shaft diameter varies more than 0.004 inch in any 0.50 inch of length, in the measurement area shown in Figure 1 of SB-26, replace the C056-1 Rev. A through G spring assembly with a C056-1 Rev. H spring assembly before further flight. (c) Replacing the C056-1 Rev. A through G spring assembly with a C056-1 Rev. H spring assembly in accordance with the service bulletin is considered terminating action for the requirements of this AD. (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 will not be issued. (f) The inspection shall be done in accordance with the Compliance Procedure contained in Robinson Helicopter Company R44 Service Bulletin SB-26, dated January 31, 1998. 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 Regional Counsel, Southwest Region, 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 April 27, 1998, to all persons except those persons to whom it was made immediately effective by Priority Letter AD 98-04-12, issued February 4, 1998, which contained the requirements of this amendment. Issued in Fort Worth, Texas, on April 3, 1998. Henry A. Armstrong, Manager, Rotorcraft Directorate, Aircraft Certification Service. [FR Doc. 98-9478 Filed 4-9-98; 8:45 am] BILLING CODE 4910-13-U