2010-27745. Airworthiness Directives; The Boeing Company Model 737-700, -700C, -800, and -900ER Series Airplanes, Model 747-400F Series Airplanes, and Model 767-200 and -300 Series Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

We propose to adopt a new airworthiness directive (AD) for certain Model 737-700, -700C, -800, and -900ER series airplanes, Model 747-400F series airplanes, and Model 767-200 and -300 series airplanes. This proposed AD would require an inspection for affected serial numbers of the crew oxygen mask stowage box units; and replacement of the crew oxygen mask stowage box unit with a new crew oxygen mask stowage unit, if necessary. This proposed AD results from reports indicating that certain crew oxygen mask stowage box units were possibly delivered with a burr in the inlet fitting. The burr may break loose during test or operation and may pose an ignition source or cause an inlet valve to jam. We are proposing this AD to prevent an ignition source, which could result in an oxygen-fed fire; or could cause an inlet valve to jam in a crew oxygen mask stowage box unit, which could result in restricted flow of oxygen.

DATES:

We must receive comments on this proposed AD by December 20, 2010.

ADDRESSES:

You may send comments by any of the following methods:

• Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
• Fax: [phone].
• Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.
• Hand Delivery: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this proposed AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone [phone], extension 1; fax [phone]; e-mail [e-mail]; Internet https://www.myboeingfleet.com. You may review copies of the referenced service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information on the availability of this material at the FAA, call 425-227-1221.

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.gov;​; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Office (telephone [phone]) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

Susan L. Monroe, Aerospace Engineer, Cabin Safety and Environmental Systems Branch, ANM-150S, FAA, Seattle Aircraft Certification Office (ACO), 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2010-1042; Directorate Identifier 2010-NM-094-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD because of those comments.

We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this proposed AD.

Discussion

We received reports indicating that crew oxygen mask stowage box units having part number (P/N) MXP147, MXP147-2, MXP147-3, MXP147-5, MXP402, and MXP410-1, that were manufactured between July 12, 2007, and November 20, 2007, were possibly delivered with a burr in the inlet fitting. If not corrected, the burr may break loose during test or operation and may pose an ignition source, which could result in an oxygen-fed fire; or could cause an inlet valve to jam in an oxygen mask stowage box unit, which could result in restricted flow of oxygen.

Relevant Service Information

We have reviewed Boeing Alert Service Bulletins 737-35A1121, dated December 14, 2009; 747-35A2126, dated October 8, 2009; and 767-35A0057, dated October 8, 2009. The service bulletins describe procedures for a general visual inspection for affected serial numbers of the crew oxygen mask stowage box units, and replacement of the affected crew oxygen mask stowage box unit with a new crew oxygen mask stowage box unit.

The service information refers to Intertechnique Service Bulletin MXP1/4-35-175, dated September 11, 2009, for inspecting the serial numbers of the crew oxygen mask stowage box units.

FAA's Determination and Requirements of This Proposed AD

We are proposing this AD because we evaluated all relevant information and determined the unsafe condition described previously is likely to exist or develop in other products of these same type designs. This proposed AD would require accomplishing the actions specified in the service information described previously.

Costs of Compliance

We estimate that this proposed AD would affect 40 airplanes of U.S. registry. We also estimate that it would take about 1 work-hour per product to comply with this proposed AD. The average labor rate is $85 per work-hour. Based on these figures, we estimate the cost of this proposed AD to the U.S. operators to be $3,400, or $85 per product.

Authority for This Rulemaking

Title 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.

We 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 air commerce 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.

Regulatory Findings

We determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would 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.

For the reasons discussed above, I certify this proposed regulation:

1. Is not a “significant regulatory action” under Executive Order 12866,

2. Is not a “significant rule” under the 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.

You can find our regulatory evaluation and the estimated costs of compliance in the AD Docket.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Incorporation by reference
• Safety

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 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. 106(g), 40113, 44701.

§ 39.13

[Amended]

2. The FAA amends § 39.13 by adding the following new AD:

The Boeing Company: Docket No. FAA-2010-1042; Directorate Identifier 2010-NM-094-AD.

Comments Due Date

(a) We must receive comments by December 20, 2010.

Affected ADs

(b) None.

Applicability

(c) This AD applies to The Boeing Company airplanes, certificated in any category, as identified in paragraphs (c)(1), (c)(2), and (c)(3) of this AD.

(1) Model 737-700, -700C, -800, -900ER series airplanes, as identified in Boeing Alert Service Bulletin 737-35A1121, dated December 14, 2009.

(2) Model 747-400F series airplanes, as identified in Boeing Alert Service Bulletin 747-35A2126, dated October 8, 2009.

(3) Model 767-200 and -300 series airplanes, as identified in Boeing Alert Service Bulletin 767-35A0057, dated October 8, 2009.

Subject

(d) Air Transport Association (ATA) of America Code 35: Oxygen.

Unsafe Condition

(e) This AD results from reports indicating that certain crew oxygen mask stowage box units were possibly delivered with a burr in the inlet fitting. The Federal Aviation Administration is issuing this AD to prevent an ignition source, which could result in an oxygen-fed fire; or could cause an inlet valve to jam in an oxygen mask stowage box unit, which could result in restricted flow of oxygen.

Compliance

(f) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.

Inspection and Corrective Action

(g) Within 24 months after the effective date of this AD: Do a general visual inspection to determine if the serial number of the crew oxygen mask stowage box units is identified in the Appendix of Intertechnique Service Bulletin MXP1/4-35-175, dated September 11, 2009, in accordance with the Accomplishment Instructions of the applicable Boeing Alert Service Bulletin listed in Table 1 of this AD. A review of airplane maintenance records is acceptable in lieu of this inspection if the serial number of the crew oxygen mask stowage box units can be conclusively determined from that review. If any crew oxygen mask stowage box unit has a serial number identified in the Appendix of Intertechnique Service Bulletin MXP1/4-35-175, dated September 11, 2009: Before further flight, replace the crew oxygen mask stowage box unit with a new unit, in accordance with the Accomplishment Instructions of the applicable Boeing alert service bulletin listed in Table 1 of this AD.

Table 1—Service Information

Boeing airplane model	Document	Date
737-700, -700C, -800, -900ER series airplanes	Boeing Alert Service Bulletin 737-35A1121	December 14, 2009.
747-400F series airplanes	Boeing Alert Service Bulletin 747-35A2126	October 8, 2009.
767-200 and -300 series airplanes	Boeing Alert Service Bulletin 767-35A0057	October 8, 2009.

Parts Installation

(h) As of the effective date of this AD, no person may install a crew oxygen mask stowage box unit identified in the Appendix of Intertechnique Service Bulletin MXP1/4-35-175, dated September 11, 2009, on any airplane.

Alternative Methods of Compliance (AMOCs)

(i)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN: Susan L. Monroe, Aerospace Engineer, Cabin Safety and Environmental Systems Branch, ANM-150S, FAA, Seattle ACO, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone [phone]; fax [phone]. Information may be e-mailed to: [e-mail].

(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 principal maintenance inspector (PMI) or principal avionics inspector (PAI), as appropriate, or lacking a principal inspector, your local Flight Standards District Office. The AMOC approval letter must specifically reference this AD.

Issued in Renton, Washington, on October 26, 2010.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.