AD 94-19-06 ACTIVE

This amendment adopts a new airworthiness directive (AD) that is applicable to certain Puritan Bennett Sweep-On Model 2000 crew masks installed on various transport and commuter category airplanes. This action requires modification of certain crew oxygen masks. This amendment is prompted by reports of difficulty in exhaling into certain crew oxygen masks due to misalignment of the demand diaphragm. The actions specified in this AD are intended to prevent the flight crew from experiencing difficulty in exhaling into the affected crew oxygen masks in the event oxygen masks are required for the crew, such as during depressurization of the airplane.

Final rule; request for comments.

94-19-06 PURITAN BENNETT AERO SYSTEMS: Amendment 39-9028. Docket 94-NM-154-AD.

Applicability: Sweep-On Model 2000 crew oxygen masks, as listed in Puritan Bennett Service Bulletin 174250-35-1, dated August 1994; as installed on, but not limited to, Dornier Model 228 and 328 series airplanes, Cessna Model 550 and 650 and Citation Model I and II series airplanes, Raytheon Corporate Jets Model HS 125-700A series airplanes, Dassault Mystere Falcon Model 20 series airplanes, Beech Model 400 (Beechjet) series airplanes, and Gulfstream Model G-1159 (G-II) and G-1159A (G-III) series airplanes; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent the flight crew from experiencing difficulty in exhaling into the affected crew oxygen masks, accomplish the following:

(a) Within 60 days after the effective date of this AD, modify the crew oxygen masks, in accordance with Puritan Bennett Service Bulletin 174250-35-1, dated August 1994.

(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, Los Angeles Aircraft Certification Office (ACO), 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, Los Angeles ACO.

NOTE: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Los Angeles ACO.

(c) 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.

(d) The modification shall be done in accordance with Puritan Bennett Service Bulletin 174250-35-1, dated August 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 Puritan Bennett Company, 108000 Pflumm Road, Lenexa, Kansas 66215. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Transport Airplane Directorate, Los Angeles Aircraft Certification Office, 3229 East Spring Street, Long Beach, California; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

(e) This amendment becomes effective on October 6, 1994.

Recently, the flight crews from various transport and commuter category airplanes reported that they experienced difficulty in exhaling into certain Puritan Bennett Sweep-On Model 2000 crew oxygen masks. Investigation revealed that the demand diaphragm on these crew oxygen masks were misaligned, which may have resulted in the seizure of the exhalation valve. This condition, if not corrected, could result in the flight crew experiencing difficulty in exhaling into the affected crew oxygen masks in the event oxygen masks are required for the crew, such as during depressurization of the airplane.

The FAA has reviewed and approved Puritan Bennett Service Bulletin 174250-35-1, dated August 1994, which describes procedures for modification of certain crew oxygen masks. This modification entails aligning the demand diaphragm in the vertical position, which would prevent the seizure of the exhalation valve.

Since an unsafe condition has been identified that is likely to exist or develop on other Puritan Bennett Sweep-On Model 2000 crew oxygen masks that are installed on various transport and commuter category airplanes, this AD is being issued to prevent the flight crew from experiencing difficulty in exhaling into the affected crew oxygen masks. This AD requires modification of certain crew oxygen masks. The actions are required to be accomplished in accordance with the service bulletin described previously.

Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days.

Comments Invited
Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited tocomment on this rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified under the caption "ADDRESSES." All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket Number 94-NM-154-AD." The postcard will be date stamped and returned to the commenter.

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 among the 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.

The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and that it is not a "significant regulatoryaction" under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, 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 the Amendment
Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) 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.

39.13 - [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-103, Attention: Rules Docket No. 94-NM-154-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.
The service information referenced in this AD may be obtained from Puritan Bennett Aero Systems Company, 108000 Pflumm Road, Lenexa, Kansas 66215. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Transport Airplane Directorate, Los Angeles Aircraft Certification Office, 3229 East Spring Street, Long Beach, California; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

Walter Eierman, Aerospace Engineer, Systems and Equipment Branch, ANM-131L, FAA, Transport Airplane Directorate, Los Angeles Aircraft Certification Office, 3229 East Spring Street, Long Beach, California 90806-2425; telephone (310) 988-5336; fax (310) 988-5310.