AD 98-16-21 Airworthiness Directives; Aerospatiale Model ATR42 and ATR72 Series Airplanes

Models named: ATR42, Model ATR72 series, ATR42 series, ATR72 series. Read the applicability below — it usually turns on serial or part numbers too.

Model ATR42 and Model ATR72 series airplanes, as listed in Avions de Transport Regional Service Bulletins ATR42-54- 0019 (for Model ATR42 series airplanes) and ATR72-54-1011 (for Model ATR72 series airplanes), both dated March 9, 1998; certificated in any category. [[Page 42223]] Note 1: This AD applies to each airplane 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 airplanes 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 wear (scratches or grooving) of the aft upper fittings of the rear engine mount, and consequent reduced structural integrity of the engine mounts, accomplish the following: (a) Within 10 months after the effective date of this AD, perform a one-time visual inspection of the stiffeners for the upper left and right engine cowls to ensure the stiffeners have the correct lower edge profile, in accordance with the Accomplishment Instructions of Avions de Transport Regional Service Bulletin ATR42- 54-0019 or ATR72-54-1011, both dated March 9, 1998, as applicable. (1) If the lower edge profile of the stiffener meets the specifications of the applicable service bulletin, no further action is required by this paragraph. (2) If the lower edge profile of the stiffener does not meet the specifications of the applicable service bulletin, prior to further flight, modify or replace the stiffener with a new stiffener in accordance with the applicable service bulletin. (b) Within 10 months after the effective date of this AD, perform a one-time detailed visual inspection for wear (scratches or grooving) of the aft upper fittings of the left-and right-hand rear engine mounts, in accordance with Avions de Transport Regional Service Bulletin ATR42-54-0019 (for Model ATR42 series airplanes) or ATR72-54-1011 (for Model ATR72 series airplanes), both dated March 9, 1998, as applicable. (1) If no wear is detected, no further action is required by this paragraph. (2) If any wear is detected that cannot be removed with a Type I or II blend-out as described in the applicable service bulletin, prior to further flight, repair in accordance with a method approved by the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate. (3) If any wear other than that specified in paragraph (b)(2) of this AD is detected, prior to further flight, repair in accordance with the Accomplishment Instructions of the applicable service bulletin. (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, International Branch, ANM-116. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, International Branch, ANM-116. Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the International Branch, ANM-116. (d) 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 airplane to a location where the requirements of this AD can be accomplished. (e) Except as provided by paragraph (b)(2) of this AD, the actions shall be done in accordance with Avions de Transport Regional Service Bulletin ATR42-54-0019, dated March 9, 1998, or Avions de Transport Regional Service Bulletin ATR72-54-1011, dated March 9, 1998, as applicable. 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 Aerospatiale, 316 Route de Bayonne, 31060 Toulouse, edex 03, France. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. Note 3: The subject of this AD is addressed in French airworthiness directives 98-069-073(B) (for Model ATR42 series airplanes), dated February 11, 1998; and 98-071-035(B) (for Model ATR72 series airplanes), dated February 11, 1998, as revised by Erratum 98-071-35(B), dated February 25, 1998. (f) This amendment becomes effective on September 11, 1998. Issued in Renton, Washington, on July 31, 1998. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 98-21102 Filed 8-6-98; 8:45 am] BILLING CODE 4910-13-U