# AD 94-06-04: Mask Regulators - Type: Airworthiness directive - Status: Current - Products: Airbus A320-111, A320-211, A320-212, A320-214, A320-231, A320-232, A320-233, Jetstream Model 4101, 747-400 Series, 747-400D Series, 747-400F Series, MD-11 and 10 more - Effective: May 23, 1994 - Published: March 22, 1994 - Issued: March 7, 1994 - Superseded by: Nothing supersedes this AD - Product type: Appliance - Amendment: 39-8852 - Docket: 93-ANE-18 - Registered aircraft: 783 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/B2171F8D3C1B54C686256A40006D085F.0001 - DRS record last changed: November 21, 2025 - Page: https://openairdocs.org/ad/94-06-04 ## Summary This amendment adopts a new airworthiness directive (AD), applicable to EROS series MF10-( )-( ) full face quick donning mask regulators, that requires replacement of the face piece and the mask shell securing screw. This amendment is prompted by reports of the plastic pin breaking which secures the mask shell with the face piece. The actions specified by this AD are intended to prevent the failure of the pin securing the mask shell to the face piece, which could result in a mask leaking oxygen and the crew losing consciousness. ## The airworthiness directive 94-06-04 EROS: Amendment 39-8852. Docket 93-ANE-18. Applicability: EROS series MF10-( )-( ) full face quick donning mask regulators installed on but not limited to Airbus A320, Boeing 747-400, British Aerospace (BAe) 125-600 and Jetstream 41, Canadair RJ, Dassault Mystere Falcon 20, McDonnell Douglas MD11, and Piper PA31T and PA42 series aircraft. Compliance: Required as indicated, unless accomplished previously. To prevent failure of the pin securing the mask shell to the face piece, which could result in a mask leaking oxygen and the crew losing consciousness, accomplish the following: (a) For EROS Model MF10-05-01 full face quick donning mask regulators, within six months after the effective date of this AD, replace the face piece and mask shell securing screw in accordance with EROS Service Bulletin (SB) No. MF10-35-44, dated July 15, 1991. (b) For all other EROS series MF10-( )-( ) full face quick donning mask regulators, within six months after theeffective date of this AD, replace the face piece and mask shell securing screw in accordance with EROS SB No. MF10-35-46, Revision 1, dated June 12, 1992. (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, Boston Aircraft Certification Office. The request should be forwarded through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Boston Aircraft Certification Office. NOTE: Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the Boston Aircraft Certification Office. (d) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the aircraft to a location where the requirements of this AD can be accomplished. (e) The modification shall be done in accordance with the following service bulletins: Document No. Pages Revision Date EROS SB No. MF10-35-44 1-8 Original July 15, 1991 Total Pages: 8. EROS SB No. MF10-35-46 1-7 1 June 12, 1992 Total Pages: 7. 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 EROS, P.O. Box 10, 78370 Plaisir, France. Copies may be inspected at the FAA, New England Region, Office of the Assistant Chief Counsel, 12 New England Executive Park, Burlington, MA; or at the Office of the Federal Register, 800 North Capitol Street NW., suite 700, Washington, DC. (f) This amendment becomes effective on May 23, 1994. ## Rule preamble ### Supplementary information A proposal to amend part 39 of the Federal Aviation Regulations to include an airworthiness directive (AD) that is applicable to EROS series MF10-( )-( ) full face quick donning mask regulators was published in the Federal Register on August 4, 1993 (58 FR 41441). That action proposed to require replacement of the face piece and the mask shell securing screw in accordance with EROS Service Bulletin (SB) No. MF10-35-44, and SB No. MF10-35-46, both dated June 11, 1991. Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received. One commenter states that the AD should include a means for the flight crew to determine that the old masks are not defective. The FAA does not concur. The flight crew should be able to readily see whether or not the original mask is broken. The pin can be inspected in accordance with EROS SB No. MF-10-35-43, dated June 11, 1991, to determine if the mask is intact. One commenter states that the compliance period should be 12 months after the effective date of this AD, as the proposed 6-month compliance period would cost operators an additional $110,000 for the purchase of additional masks to use while in the process of inspecting those masks already in service. The FAA does not concur. EROS SB No. MF10-35-44 was issued on July 15, 1991, and service data indicates that a substantial portion of the masks in service have already been inspected. The FAA believes that the proposed 6-month compliance period properly balances the needs of flight safety with operations concerns of operators. Although the NPRM stated the date of this SB as June 11, 1991, the correct date for this SB is July 15, 1991. In addition, the NPRM referred to the original version of EROS SB No. MF10-35-46, dated June 11, 1991. The correct revision and date for this SB is Revision 1, dated June 12, 1992. The final rule has been changed accordingly. After careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule with the changes described previously. The FAA estimates that 2,500 regulators are affected by this AD, that it will take approximately 0.5 work hours per regulators to accomplish the required actions, and that the average labor rate is $55 per work hour. Required parts will cost $535 per faceplate. Based on these figures, the total cost impact of the proposed AD on U.S. operators is estimated to be $1,406,250. The manufacturer has advised the FAA, however, that it may supply the require parts at no cost, thereby reducing the total cost impact on U.S. operators. The regulations adopted herein will not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities amongthe various levels of government. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. For the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES." List of Subjects in 14 CFR Part 39 Air Transportation, Aircraft, Aviation Safety, Incorporation by reference, Safety. Adoption of theAmendment Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends 14 CFR part 39 of the Federal Aviation Regulations as follows: PART 39 - AIRWORTHINESS DIRECTIVES 1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g); and 14 CFR 11.89. ยง39.13 - (AMENDED) 2. Section 39.13 is amended by adding the following new airworthiness directive: ## Affected data sheets (9) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS A28NM](https://openairdocs.org/tcds/A28NM): Airbus SAS; names 7 of 50 models: A320-111, A320-211, A320-212, A320-214, A320-231, A320-232, A320-233 - [TCDS A7EU](https://openairdocs.org/tcds/A7EU): Dassault Aviation; names 4 of 11 models: Mystere-Falcon 20 - D5, Mystere-Falcon 20 - C5, Mystere-Falcon 20 - F5, Mystere-Falcon 20 - E5 - [TCDS A20WE](https://openairdocs.org/tcds/A20WE): The Boeing Company; names 3 of 14 models: 747-400D Series, 747-400F Series, 747-400 Series - [TCDS A23SO](https://openairdocs.org/tcds/A23SO): Piper Aircraft Inc.; names 3 of 3 models: PA-42-1000, PA-42, PA-42-720 - [TCDS A22WE](https://openairdocs.org/tcds/A22WE): The Boeing Company; names 1 of 11 models: MD-11 - [TCDS A32SO](https://openairdocs.org/tcds/A32SO): Piper Aircraft Inc.; names 1 of 1 models: PA-42-720R - [TCDS A3EU](https://openairdocs.org/tcds/A3EU): Textron Aviation Inc.; names 1 of 50 models: BH.125 Series 600A - [TCDS A41NM](https://openairdocs.org/tcds/A41NM): BAE Systems (Operations) Limited; names 1 of 1 models: Jetstream Model 4101 - [TCDS A8EA](https://openairdocs.org/tcds/A8EA): Piper Aircraft Inc.; names 1 of 6 models: PA-31T ## 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: 783 (783 by airframe model, 0 by engine model) - Makers: Airbus 377, Airbus Industrie 184, Piper 146, Boeing 53, Dassault-Breguet 14, Mcdonnell Douglas 4, Airbus S A S 2, Dassault 2, Avions Marcel Dassault 1 Models with the most aircraft: - [Airbus A320-232](https://openairdocs.org/model/airbus-a320-232): 189 aircraft (airframe model) - [Airbus A320-214](https://openairdocs.org/model/airbus-a320-214): 160 aircraft (airframe model) - [Airbus Industrie A320-232](https://openairdocs.org/model/airbus-industrie-a320-232): 109 aircraft (airframe model) - [Piper PA-31T](https://openairdocs.org/model/piper-pa-31t): 87 aircraft (airframe model) - [Airbus Industrie A320-212](https://openairdocs.org/model/airbus-industrie-a320-212): 39 aircraft (airframe model) - [Airbus Industrie A320-214](https://openairdocs.org/model/airbus-industrie-a320-214): 26 aircraft (airframe model) - [Piper PA-42-1000](https://openairdocs.org/model/piper-pa-42-1000): 23 aircraft (airframe model) - [Airbus A320-233](https://openairdocs.org/model/airbus-a320-233): 21 aircraft (airframe model) - [Piper PA-42-720](https://openairdocs.org/model/piper-pa-42-720): 18 aircraft (airframe model) - [Piper PA-42](https://openairdocs.org/model/piper-pa-42): 17 aircraft (airframe model) - [Boeing 747-446](https://openairdocs.org/model/boeing-747-446): 10 aircraft (airframe model) - [Dassault-Breguet MYSTERE FALCON 20-F5](https://openairdocs.org/model/dassault-breguet-mystere-falcon-20-f5): 10 aircraft (airframe model) - [Boeing 747-422](https://openairdocs.org/model/boeing-747-422): 8 aircraft (airframe model) - [Airbus Industrie A320-211](https://openairdocs.org/model/airbus-industrie-a320-211): 6 aircraft (airframe model) - [Boeing 747-412](https://openairdocs.org/model/boeing-747-412): 5 aircraft (airframe model) - [Boeing 747-400F](https://openairdocs.org/model/boeing-747-400f): 4 aircraft (airframe model) - [Boeing 747-409](https://openairdocs.org/model/boeing-747-409): 4 aircraft (airframe model) - [Mcdonnell Douglas MD-11](https://openairdocs.org/model/mcdonnell-douglas-md-11): 4 aircraft (airframe model) - [Boeing 747-481F](https://openairdocs.org/model/boeing-747-481f): 3 aircraft (airframe model) - [Boeing 747-409F](https://openairdocs.org/model/boeing-747-409f): 3 aircraft (airframe model) All 42 models: https://openairdocs.org/ad/94-06-04/models.md Every aircraft: https://openairdocs.org/ad/94-06-04/aircraft.md 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.