# AD 97-04-09: Main Landing Gear - Type: Airworthiness directive - Status: Historical - Products: ATR GIE Avions de Transport R gional ATR42-300 and ATR42-320 - Effective: March 7, 1997 - Published: February 20, 1997, 62 FR 7665–7667 - Issued as: Final rule; request for comments - Superseded by: [AD 97-26-19](https://openairdocs.org/ad/97-26-19) - Product type: Aircraft, Large airplane - Amendment: 39-9933 - Docket: 97-NM-24-AD - Registered aircraft: 20 may be affected, by airframe or engine model (OpenAirDocs) - Official PDF: https://openairdocs.org/files/sha256/5e/01/5e01e1b49db43eb4f159ffb79a71027b0ea94f494a053b6c7086e3bfaf6f5852 (from https://www.govinfo.gov/content/pkg/FR-1997-02-20/pdf/97-3843.pdf) - Federal Register: https://www.federalregister.gov/documents/1997/02/20/97-3843/airworthiness-directives-aerospatiale-model-atr42-300-and-atr42--320-series-airplanes - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/FD5D17451C77205386256A170051DC21.0001 - DRS record last changed: August 7, 2025 - Page: https://openairdocs.org/ad/97-04-09 ## The airworthiness directive 97-04-09 AEROSPATIALE: Amendment 39-9933. Docket 97-NM-24-AD. Applicability: Model ATR42-300 and ATR42-320 series airplanes, on which the lower lugs of the barrel of the main landing gear (MLG) have been overhauled or repaired, certificated in any category. NOTE 1: This AD does not affect new barrel assemblies that have never been overhauled or repaired. NOTE 2: 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 (b) 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. Compliance: Required as indicated, unless accomplished previously. To prevent fatigue cracking in the lower lugs of the barrel and consequent collapse of the MLG, accomplish the following: (a) Prior to the accumulation of 2 years time-in-service since last overhaul or repair of the barrel lower lugs of the MLG, or within 60 days after the effective date of this AD, whichever occurs later, 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. (1) If no echo is detected or the echo is less than 20%, repeat the ultrasonic inspection thereafter at intervals not to exceed 700 landings. (2) If any echo is greater than or equal to 20%, prior to furtherflight, replace the barrel assembly with a new or serviceable barrel assembly, in accordance with the service bulletin. After replacement, prior to the accumulation of 2 years time-in-service on that replacement part, accomplish the actions specified in paragraph (a) of this AD. (b) 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, Standardization Branch, ANM-113, 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, Standardization Branch, ANM-113. NOTE 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Standardization Branch, ANM-113. (c) Special flight permits may be issued in accordance with sections 21.197 and 21.199of 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. (d) The inspections and replacement shall be done in accordance with Messier-Dowty Service Bulletin 631-32-132, dated January 21, 1997. 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, 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. (e) This amendment becomes effective on March 7, 1997. ## Affected data sheets (1) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS A53EU](https://openairdocs.org/tcds/A53EU): ATR – GIE Avions de Transport Régional; names 2 of 11 models: ATR42-300, ATR42-320 ## Registered aircraft it may apply to (OpenAirDocs) Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment. - Aircraft: 20 (20 by airframe model, 0 by engine model) - Makers: Aerospatiale/Aeritalia 16, Aerospatiale/Alenia 2, Atr-Gie Avions De Transport 1, Atr-Gie Avions De Trnsp Rgnl 1 Models with the most aircraft: - [Aerospatiale/Aeritalia ATR 42-300](https://openairdocs.org/model/aerospatiale-aeritalia-atr-42-300): 12 aircraft (airframe model) - [Aerospatiale/Aeritalia ATR 42-320](https://openairdocs.org/model/aerospatiale-aeritalia-atr-42-320): 4 aircraft (airframe model) - [Aerospatiale/Alenia ATR 42-320](https://openairdocs.org/model/aerospatiale-alenia-atr-42-320): 2 aircraft (airframe model) - [Atr-Gie Avions De Transport ATR-42-320](https://openairdocs.org/model/atr-gie-avions-de-transport-atr-42-320): 1 aircraft (airframe model) - [Atr-Gie Avions De Trnsp Rgnl ATR 42-300](https://openairdocs.org/model/atr-gie-avions-de-trnsp-rgnl-atr-42-300): 1 aircraft (airframe model) All 5 models: https://openairdocs.org/ad/97-04-09/models.md Every aircraft: https://openairdocs.org/ad/97-04-09/aircraft.md ## Related documents - [AD 97-26-19](https://openairdocs.org/ad/97-26-19) (historical): Lower Lugs Of Barrel Of Main Landing Gear · ATR GIE Avions de Transport R gional ATR42-300 and ATR42-320. Effective Jan 7, 1998. Supersedes this AD No proposed rule in this release led to it. Its text cites no advisory circulars or STCs. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.