AD 97-26-19 Airworthiness Directives; Aerospatiale Model ATR42-300 and ATR42- 320 Series Airplanes

Models named: ATR42-300, ATR42-320 series. Read the applicability below — it usually turns on serial or part numbers too.

All Model ATR42-300 and ATR42-320 series airplanes, certificated in any category. Note 1: This AD applies to each airplane 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 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 (e) 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. [[Page 66982]]

Required as indicated, unless accomplished previously. To detect and correct fatigue cracking in the lower lugs of the barrel of the main landing gear (MLG), and consequent collapse of the MLG, accomplish the following: (a) Perform an ultrasonic inspection to detect fatigue cracks of the lower lugs of the barrel of the MLG, in accordance with Messier- Dowty Service Bulletin 631-32-132, dated January 21, 1997, at the time specified in paragraph (a)(1) or (a)(2) of this AD, as applicable: (1) Within 2 years after the last overhaul or repair of the lower lugs of the barrel of the MLG, or within 60 days after March 7, 1997 (the effective date of AD 97-04-09, amendment 39-9933), whichever occurs later; or (2) Within 5 years after the installation of a new MLG barrel assembly, or within 60 days after the effective date of this AD, whichever occurs later. (b) If, during any inspection required by this AD, no echo is detected, or if the echo is less than 20%, repeat the ultrasonic inspection thereafter at intervals not to exceed 900 landings. (c) If, during any inspection required by this AD, the echo is greater than or equal to 20%, prior to further flight, replace the MLG barrel assembly with a new or serviceable MLG barrel assembly, in accordance with the service bulletin. (1) If the damaged barrel assembly is replaced with an overhauled or repaired assembly, within 2 years after installation of that overhauled or repaired part, accomplish the actions specified in paragraph (a) of this AD. (2) If the damaged barrel assembly is replaced with a new barrel assembly, within 5 years after installation of that new part, accomplish the actions specified in paragraph (a) of this AD. (d) Modification of the lower lugs of the barrel of the MLG in accordance with Messier-Dowty Service Bulletin 631-32-133, dated February 24, 1997, as revised by Messier-Dowty Service Bulletin Change Notice No. 1, dated March 18, 1997, constitutes terminating action for the repetitive inspection requirements of this AD. (e) 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, FAA, Transport Airplane Directorate. 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. (f) 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. (g) The actions shall be done in accordance with Messier-Dowty Service Bulletin 631-32-133, dated February 24, 1997, as revised by Messier-Dowty Service Bulletin Change Notice No. 1, dated March 18, 1997; and Messier-Dowty Service Bulletin 631-32-132, dated January 21, 1997. (1) The incorporation by reference of Messier-Dowty Service Bulletin 631-32-133, dated February 24, 1997, as revised by Messier- Dowty Service Bulletin Change Notice No. 1, dated March 18, 1997, is approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. (2) The incorporation by reference of Messier-Dowty Service Bulletin 631-32-132, dated January 21, 1997, was approved previously by the Director of the Federal Register as of March 7, 1997 (62 FR 7665, February 20, 1997). (3) Copies may be obtained from Aerospatiale, 316 Route de Bayonne, 31060 Toulouse, Cedex 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 directive 96-294(B)R1, dated September 10, 1997. (h) This amendment becomes effective on January 7, 1998. Issued in Renton, Washington, on December 15, 1997. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 97-33509 Filed 12-22-97; 8:45 am] BILLING CODE 4910-13-U