# AD 95-11-06: Main Gear Box Oil Pressure Switch - Type: Airworthiness directive - Status: Current - Products: Airbus Helicopters AS350B, AS350B1, AS350B2, AS350BA and AS350D - Effective: June 9, 1995 - Published: May 25, 1995, 60 FR 27686–27688 - Issued: May 25, 1995 - Issued as: Final rule; request for comments - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Rotorcraft - Amendment: 39-9240 - Docket: 95-SW-10-AD - Registered aircraft: 272 may be affected, by airframe or engine model (OpenAirDocs) - Official PDF: https://openairdocs.org/files/sha256/e8/de/e8de210901de58a99da9f530f4aac5e69f561a5696c56fb0f8b179714cae26e9 (from https://www.govinfo.gov/content/pkg/FR-1995-05-25/pdf/95-12608.pdf) - Federal Register: https://www.federalregister.gov/documents/1995/05/25/95-12608/airworthiness-directives-societe-nationale-industrielle-aerospatiale-and-eurocopter-france-model - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/B3E1531C3CEC1E4A86256A4D006AE8CA.0001 - DRS record last changed: November 21, 2025 - Page: https://openairdocs.org/ad/95-11-06 ## The airworthiness directive 95-11-06 SOCIETE NATIONALE INDUSTRIELLE AEROSPATIALE and EUROCOPTER FRANCE: Amendment 39-9240. Docket No. 95-SW-10-AD. Applicability: Model AS-350B, BA, D, B1, and B2 helicopters, with main gearbox (MGB) oil pressure switch (switch) part number (P/N) 704A37-721-082 (S1130-021-082), modification number 350A07-7141, 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 describedin this AD. Such a request should include an assessment of the effect of the changed configuration of 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. Compliance: Required as indicated, unless accomplished previously. To prevent an undetected loss of MGB oil pressure, loss of the MGB, loss of power to the main rotor system, and subsequent loss of control of the helicopter, accomplish the following: (a) Until the MGB switch installation required by paragraph (c) of this AD is accomplished, during each shutdown of the helicopter engine, check to ensure that the MGB oil pressure warning light illuminates. If it does not illuminate, before further flight, replace the MGB switch in accordance with paragraph (c) of this AD. (b) The operational check required by paragraph (a) of this AD may be performed by an owner/operator holding at least a private pilot certificate and must be entered into the aircraft records showing compliance with this AD in accordance with 14 CFR sections 43.11 and 91.417(a)(2)(v). (c) Within 30 days after the effective date of this AD, remove the MGB switch, P/N 704A37-721-082 (S1130-021-082), modification number 350A07-7141, and replace with MGB switch, P/N 704A37-721-089 (S1130-021-089), modification number 350A07-7152, or Jaeger MGB switch, P/N 704A37-721-014 (068651.54/350A32-3134-00) in accordance with paragraph CC (1) of Eurocopter Service Bulletin AS-350, No. 01.43, Revision 1, dated April 21, 1994. NOTE 2: The MGB switch P/N is engraved on the MGB switch casing. (d) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used when approved by the Manager, Rotorcraft Standards Staff, FAA, Rotorcraft Directorate. Operators shall submit their requests through an FAA Principal Maintenance Inspector, who may concur orcomment and then send it to the Manager, Rotorcraft Standards Staff. NOTE 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Rotorcraft Standards Staff. (e) The check, removal, and replacement shall be done in accordance with Eurocopter Service Bulletin AS-350, No. 01.43, Revision 1, dated April 21, 1994. 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. Copies may be inspected at the FAA, Office of the Assistant Chief Counsel, 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. (f) This amendment becomes effective on June 9, 1995. ## Affected data sheets (1) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS H9EU](https://openairdocs.org/tcds/H9EU): Airbus Helicopters; names 5 of 10 models: AS350B, AS350B2, AS350B1, AS350D, AS350BA ## 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: 272 (272 by airframe model, 0 by engine model) - Makers: Eurocopter 160, Aerospatiale 44, American Eurocopter 38, Airbus Helicopters 12, Eurocopter France 11, S N I A S 7 Models with the most aircraft: - [Eurocopter AS 350 B2](https://openairdocs.org/model/eurocopter-as-350-b2): 146 aircraft (airframe model) - [American Eurocopter AS350B2](https://openairdocs.org/model/american-eurocopter-as350b2): 38 aircraft (airframe model) - [Aerospatiale AS350BA](https://openairdocs.org/model/aerospatiale-as350ba): 18 aircraft (airframe model) - [Aerospatiale AS350B](https://openairdocs.org/model/aerospatiale-as350b): 13 aircraft (airframe model) - [Eurocopter AS 350 BA](https://openairdocs.org/model/eurocopter-as-350-ba): 13 aircraft (airframe model) - [Aerospatiale AS350B2](https://openairdocs.org/model/aerospatiale-as350b2): 11 aircraft (airframe model) - [Airbus Helicopters AS350B2](https://openairdocs.org/model/airbus-helicopters-as350b2): 10 aircraft (airframe model) - [Eurocopter France AS350B2](https://openairdocs.org/model/eurocopter-france-as350b2): 8 aircraft (airframe model) - [S N I A S AS-350B ECUREUIL](https://openairdocs.org/model/s-n-i-a-s-as-350b-ecureuil): 5 aircraft (airframe model) - [Airbus Helicopters AS350BA](https://openairdocs.org/model/airbus-helicopters-as350ba): 2 aircraft (airframe model) - [Aerospatiale AS350B1 ECUREUIL](https://openairdocs.org/model/aerospatiale-as350b1-ecureuil): 2 aircraft (airframe model) - [Eurocopter France AS350BA](https://openairdocs.org/model/eurocopter-france-as350ba): 2 aircraft (airframe model) - [S N I A S AS350D ASTAR](https://openairdocs.org/model/s-n-i-a-s-as350d-astar): 1 aircraft (airframe model) - [Eurocopter AS350B](https://openairdocs.org/model/eurocopter-as350b): 1 aircraft (airframe model) - [S N I A S AS350BA](https://openairdocs.org/model/s-n-i-a-s-as350ba): 1 aircraft (airframe model) - [Eurocopter France AS350B](https://openairdocs.org/model/eurocopter-france-as350b): 1 aircraft (airframe model) All 17 models: https://openairdocs.org/ad/95-11-06/models.md Every aircraft: https://openairdocs.org/ad/95-11-06/aircraft.md 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.