AD 2008-06-24

We are adopting a new airworthiness directive (AD) for certain Boeing Model 737-300, -400, and -500 series airplanes. This AD requires an inspection to determine the manufacturer and manufacture date of the oxygen masks in the passenger service unit and the lavatory and attendant box assemblies, corrective action if necessary, and other specified action. This AD results from a report that several passenger masks with broken in-line flow indicators were found following a mask deployment. We are issuing this AD to prevent the in-line flow indicators of the passenger oxygen masks from fracturing and separating, which could inhibit oxygen flow to the masks and consequently result in exposure of the passengers and cabin attendants to hypoxia following a depressurization event.

Final rule.

2008-06-24 Boeing: Amendment 39-15436. Docket No. FAA-2007-0346; Directorate Identifier 2007-NM-202-AD. \n\nEffective Date \n\n\t(a) This airworthiness directive (AD) is effective April 23, 2008. \n\nAffected ADs \n\n\t(b) None. \n\nApplicability \n\n\t(c) This AD applies to Boeing Model 737-300, -400, and -500 series airplanes, certificated in any category; as identified in Boeing Special Attention Service Bulletin 737-35-1099, dated April 9, 2007. \n\nUnsafe Condition \n\n\t(d) This AD results from a report that several passenger masks with broken in-line flow indicators were found following a mask deployment. We are issuing this AD to prevent the in-line flow indicators of the passenger oxygen masks from fracturing and separating, which could inhibit oxygen flow to the masks and consequently result in exposure of the passengers and cabin attendants to hypoxia following a depressurization event. \n\nCompliance \n\n\t(e) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done. \n\nInspection and Related Investigative/Corrective Actions if Necessary \n\n\t(f) Within 60 months after the effective date of this AD, do a general visual inspection to determine the manufacturer and manufacture date of the oxygen masks in the passenger service unit and the lavatory and attendant box assemblies, and do the applicable corrective action and other specified action, by accomplishing all of the applicable actions specified in the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-35- 1099, dated April 9, 2007; except where the service bulletin specifies repairing the oxygen mask assembly, replace it with a new or modified oxygen mask assembly having an improved flow indicator. The corrective action and other specified action must be done before further flight. \n\n\tNote 1: Boeing Special Attention Service Bulletin 737-35-1099 refers to B/E Aerospace Service Bulletin 174080-35-01, dated February 6, 2006; and Revision 1, dated May 1, 2006; as additional sources of service information for modifying the oxygen mask assembly by replacing the flow indicator with an improved flow indicator. \n\nAlternative Methods of Compliance (AMOCs) \n\n\t(g)(1) The Manager, Seattle Aircraft Certification Office, FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19. \n\t(2) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Before using any approved AMOC on any airplane to which the AMOC applies, notify your appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO. \n\nMaterial Incorporated by Reference \n\n\t(h) You must use Boeing Special Attention Service Bulletin 737- 35-1099, dated April 9, 2007, to do the actions required by this AD, unless the AD specifies otherwise. \n\t(1) The Director of the Federal Register approved the incorporation by reference of this service information under 5 U.S.C. 552(a) and 1 CFR part 51. \n\t(2) For service information identified in this AD, contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207. \n\t(3) You may review copies of the service information incorporated by reference at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_ regulations/ibr_locations.html.

Discussion \n\n\tWe issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an airworthiness directive (AD) that would apply to certain Model Boeing 737-300, -400, and -500 series airplanes. That NPRM was published in the Federal Register on December 19, 2007 (72 FR 71830). That NPRM proposed to require an inspection to determine the manufacturer and manufacture date of the oxygen masks in the passenger service unit (PSU) and the lavatory and attendant box assemblies, corrective action if necessary, and other specified action. \n\nComments \n\n\tWe gave the public the opportunity to participate in developing this AD. We received no comments on the NPRM or on the determination of the cost to the public. \n\nConclusion \n\n\tWe reviewed the relevant data and determined that air safety and the public interest require adopting the AD as proposed. \n\nCosts of Compliance \n\n\tThere are about 1,956 airplanes of the affected design in the worldwide fleet. This AD affects about 646 airplanes of U.S. registry. The required actions take about 16 work hours per airplane, for an average of 180 oxygen masks per airplane distributed in about 45 PSUs/ oxygen boxes, at an average labor rate of $80 per work hour. Required parts cost about $6 per oxygen mask, or $1,080 per airplane. Based on these figures, the estimated cost of the AD for U.S. operators is $1,524,560, or $2,360 per airplane. \n\nAuthority for This Rulemaking \n\n\tTitle 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. "Subtitle VII: Aviation Programs,'' describes in more detail the scope of the Agency's authority. \n\tWe are issuing this rulemaking under the authority described in "Subtitle VII, Part A, Subpart III, Section 44701: General requirements.'' Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in aircommerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action. \n\nRegulatory Findings \n\n\tThis AD will not have federalism implications under Executive Order 13132. This AD will not have a substantial direct effect 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. \n\tFor the reasons discussed above, I certify that this AD: \n\t(1) Is not a "significant regulatory action'' under Executive Order 12866, \n\t(2) Is not a "significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), and \n\t(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. \n\tYou can find our regulatory evaluation and the estimated costs of compliance in the AD Docket. \n\nList of Subjects in 14 CFR Part 39 \n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. \n\nAdoption of the Amendment \n\nAccordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows: \n\nPART 39--AIRWORTHINESS DIRECTIVES \n\n1. The authority citation for part 39 continues to read as follows: \n\n\tAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\nSec. 39.13 (Amended) \n\n2. The FAA amends Sec. 39.13 by adding the following new AD: