AD 2001-18-13 Airworthiness Directives; Eurocopter Deutschland GmbH Model EC135 P1 and EC135 T1 Helicopters

Models named: EC135 P1, EC135 T1. Read the applicability below — it usually turns on serial or part numbers too.

Model EC135 P1 and EC135 T1 helicopters, with main rotor drive torque strut assembly (strut), part number (P/N) L633M1001 103 or L633M1001 105, 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 (f) 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 failure of the strut and subsequent loss of control of the helicopter, accomplish the following: (a) Before further flight, insert a copy of this AD or a statement into the Emergency Procedures Section of the Rotorcraft Flight Manual (RFM) to inform the pilot to reduce power and land as soon as practicable if a thump-like sound followed by unusual vibration occurs during flight. (b) Within 10 hours time-in-service (TIS), visually inspect each strut with 950 or more hours TIS for a crack or a break using a flashlight and a mirror in accordance with the Accomplishment Instructions, paragraph 3.B.(1) and 3.B.(2), of Eurocopter Deutschland GmbH Alert Service Bulletin EC135-63A-002, Revision 1, dated March 12, 2001 (ASB). Replace any cracked or broken strut with an airworthy strut before further flight. (c) Inspect the following struts for a crack or a break, using a 6-power or higher magnifying glass, and re-mark and relocate each strut in accordance with the Accomplishment Instructions, paragraph 3.C., of the ASB. This AD does not require you to return any part to the manufacturer. (1) For a strut with less than 950 hours TIS, inspect before accumulating 1000 hours TIS. (2) For a strut with 950 or more hours TIS, inspect within 50 hours TIS. (3) Replace any cracked or broken strut with an airworthy strut before further flight. (d) This AD revises the Airworthiness Limitations section of the maintenance manual by establishing a life limit of 1000 hours TIS for each strut, P/N L633M1001 103 and L633M1001 105, in its original location, with an additional 1000 hours TIS if properly re-marked and relocated (2000 hours total TIS) in accordance with the Accomplishment Instructions, paragraph 3.C.(3) of the ASB. (e) Record details of the inspections in the historical or equivalent records in accordance with the Accomplishment Instructions, paragraph 3.C.(4) of the ASB. (f) 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, Regulations Group, Rotorcraft Directorate, FAA. Operators shall submit their requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Regulations Group. Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Regulations Group. (g) 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. (h) The inspections, re-marking, relocation, and entry in the historical or equivalent record of each strut, P/N L633M1001 103 and L633M1001 105, shall be done in accordance with the Accomplishment Instructions, paragraphs 3.B.(1), 3.B.(2), and 3.C., of Eurocopter Deutschland GmbH Alert Service Bulletin EC135-63A-002, Revision 1, dated March 12, 2001. 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 American Eurocopter Corporation, 2701 Forum Drive, Grand Prairie, Texas 75053-4005, telephone (972) 641-3460, fax (972) 641-3527. 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. (i) This amendment becomes effective on October 1, 2001. Note 3: The subject of this AD is addressed in Luftfahrt-Bundesamt (Federal Republic of Germany) AD 2001-107, dated March 13, 2001. Issued in Fort Worth, Texas, on September 4, 2001. David A. Downey, Manager, Rotorcraft Directorate, Aircraft Certification Service. [FR Doc. 01-22946 Filed 9-13-01; 8:45 am] BILLING CODE 4910-13-U