Airworthiness Directives; The Boeing Company Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Supplemental notice of proposed rulemaking (NPRM); reopening of comment period.

SUMMARY:

We are revising an earlier proposed airworthiness directive (AD) for certain 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. That NPRM proposed to 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. That NPRM was prompted by reports indicating that certain crew oxygen mask stowage box units were possibly delivered with a burr in the inlet fitting. The burr might break loose during test or operation, and might pose an ignition source or cause an inlet valve to jam. This action revises that NPRM by adding a step to identify and label certain crew oxygen mask stowage box units that have already been inspected and reworked by the supplier, and allowing operators to install new or serviceable crew oxygen mask stowage box units. We are proposing this supplemental NPRM to prevent an ignition source, which could result in an oxygen-fed fire; or an inlet valve jam in a crew oxygen mask stowage box unit, which could result in restricted flow of oxygen. Since these actions impose an additional burden over that proposed in the NPRM, we are reopening the comment period to allow the public the chance to comment on these proposed changes.

DATES:

We must receive comments on this supplemental NPRM by October 22, 2012.

ADDRESSES:

You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods:

• Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
• Fax: 202-493-2251.
• 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 Boeing 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 206-544-5000, extension 1; fax 206-766-5680; Internet https://www.myboeingfleet.com. For Intertechnique service information identified in this proposed AD, contact Zodiac, 2, rue Maurice Mallet—92137 Issy-les-Moulineaux Cedex France; telephone +33 1 41 23 23 23; fax +33 1 46 48 83 87; Internet http://www.zodiac.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 (phone: 800-647-5527) 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; phone: 425-917-6457; fax: 425-917-6590; email susan.l.monroe@faa.gov.

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 issued an NPRM to amend 14 CFR part 39 to include an AD that would apply to certain 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. That NPRM published in the Federal Register on November 3, 2010 (75 FR 67637). That NPRM proposed to 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.

Actions Since Previous NPRM (75 FR 67637, November 3, 2010) was Issued

The NPRM (75 FR 67637, November 3, 2010) referred to the following service information:

• Boeing Alert Service Bulletin 737-35A1121, dated December 14, 2009;
• Boeing Alert Service Bulletin 747-35A2126, dated October 8, 2009;
• Boeing Alert Service Bulletin 767-35A0057, dated October 8, 2009; and
• Intertechnique Service Bulletin MXP1/4-35-175, dated September 11, 2009.

After we issued the NPRM, the service information was revised:

• Boeing Alert Service Bulletin 737-35A1121, Revision 1, dated November 7, 2011;
• Boeing Alert Service Bulletin 747-35A2126, Revision 1, dated September 29, 2011;
• Boeing Alert Service Bulletin 767-35A0057, Revision 1, dated November 17, 2011; and
• Intertechnique Service Bulletin MXP1/4-35-175, Revision 2, dated May 10, 2011.

Among other things, the service information provides the following changes:

• Adds a step to identify and label certain crew oxygen mask stowage box units that have already been inspected and reworked by the supplier; and
• Adds a provision to allow operators to install either new or serviceable crew oxygen mask stowage box units.

Comments

We gave the public the opportunity to comment on the previous NPRM (75 FR 67637, November 3, 2010). The following presents the comments received on the NPRM and the FAA's response to each comment.

Support for the Previous NPRM (75 FR 67637, November 3, 2010)

Boeing, Air Line Pilots Association, International (ALPA), and Delta Air Lines (Delta) supported the NPRM (75 FR 67637, November 3, 2010).

Request To Revise Compliance Time

ALPA requested that we reduce the compliance time to 12 months instead of 24 months, as proposed in the previous NPRM (75 FR 67637, November 3, 2010). ALPA noted that certain crew oxygen mask stowage box units were possibly delivered with a burr in the inlet fitting, which might break loose during test or operation, and might pose an ignition source or cause an inlet valve to jam, thus prohibiting or restricting the flow of oxygen. ALPA reasoned that there could be a potential serious nature of events involving fire and smoke, and that there is a necessity to ensure functionality of this safety equipment for the flightcrew.

We disagree with the request to revise the compliance time in the supplemental NPRM. The proposed compliance time is in line with the manufacturer's recommended compliance time. Also, in developing the proposed compliance time, we considered safety implications, parts availability, and normal maintenance schedules for timely accomplishment of replacement of the crew oxygen mask stowage box units. Further, operators are permitted to accomplish the requirements of an AD at a time earlier than the specified compliance time. If additional data are presented that would justify a shorter compliance time, we might consider further rulemaking on this issue. We have not changed the supplemental NPRM in this regard.

Request for Clarification of Inspection

Japan Airlines (JAL) requested that we revise the previous NPRM (75 FR 67637, November 3, 2010) to include the latest service information. JAL explained that Intertechnique Service Bulletin MXP1/4-35-175, dated September 11, 2009, does not describe how to differentiate parts before and after the actions specified in Intertechnique Service Bulletin MXP1/4-35-175, dated September 11, 2009, have been accomplished, so it is not sufficient for operators to complete Intertechnique Service Bulletin MXP1/4-35175, dated September 11, 2009.

Continental Airlines (Continental) requested that we revise the previous NPRM (75 FR 67637, November 3, 2010) to clarify which crew oxygen mask stowage box units have been inspected, and which crew oxygen mask stowage box units still need to be inspected. Continental explained that some operators might think a placard should be applied to all crew oxygen mask stowage box units after completion of Intertechnique Service Bulletin MXP1/4-35-175, dated September 11, 2009, not only to those crew oxygen mask stowage box units with suspect serial numbers itemized in table 1 of Intertechnique Service Bulletin MXP1/4-35-175, dated September 11, 2009. Continental based this assertion on the assumption that, when a suspect crew oxygen mask stowage box unit is found with the placard already installed, it has already been re-worked and has since been returned to service.

We agree to include the revised service information in the supplemental NPRM. We have explained the revised service information in the “Actions Since Previous NPRM was Issued” section of this supplemental NPRM. The revised service information addresses the issues raised by JAL and Continental. We have revised the paragraphs specifying service information in this supplemental NPRM accordingly.

Request for Clarification Regarding Service Information for Other Models

Continental questioned why Boeing did not release service bulletins for other fleet types using the same part numbers listed in Intertechnique Service Bulletin MXP1/4-35-175, dated September 11, 2009. Continental explained that it has other fleets (for example, Model 737-500, 757-200, and 757-300 airplanes) that have the same crew oxygen mask stowage box unit part numbers, as delivered from Boeing. Continental reasoned that, because crew oxygen mask stowage box units are often swapped from aircraft to aircraft and borrowed from operator to operator, it will not only be inspecting its entire Model 737NG (next generation) fleet, but its other fleet types for these suspect serial numbers.

We find that clarification is necessary. Some airplanes were delivered with the affected part numbers and were not included in the applicability of the supplemental NPRM, because the manufacturing defect occurred in the time period from July 12, 2007, through November 20, 2007. Certain airplanes were not included in the service information because they were delivered prior to the time interval of the defect, thus were not included in the applicability of the supplemental NPRM.

Also, we now understand that the components identified with the manufacturing defect may have been installed on airplanes outside the effectivity of the service information after delivery (e.g., during maintenance activity). We are working to evaluate the associated risk and the need for additional action. We might consider further rulemaking to address our findings. We have not changed the supplemental NPRM in this regard.

Request for Alternative Method of Compliance (AMOC)

Continental stated that, if a later revision of the referenced service information is released, it would request approval of an AMOC because of minor discrepancies found in the original service information. Continental explained that it understood Revision 1 of the service information was going to be released prior to the issuance of any rulemaking, and that it has conveyed the minor discrepancies to Boeing.

As stated previously, we have revised this supplemental NPRM to refer to the revised service information—which addresses the discrepancies identified by Continental.

Request for Clarification

AVOX Systems Inc. (Avox) requested that we revise the NPRM (75 FR 67637, November 3, 2010) to include certain words, phrases, and deletions as follows:

• Where the NPRM (75 FR 67637, November 3, 2010) proposed to require replacing crew oxygen mask stowage box units, Avox requested specifying these units as `affected.'
• Where the NPRM (75 FR 67637, November 3, 2010) proposed to require replacing with a new crew oxygen mask stowage box unit, Avox requested specifying replacement with a new `or reworked' crew oxygen mask stowage box unit.
• Where the NPRM (75 FR 67637, November 3, 2010) proposed to require replacing with a new crew oxygen mask stowage box unit, Avox requested adding “as required.” Avox explained that, for crew oxygen mask stowage box units located on an airplane, it makes sense that these crew oxygen mask stowage box units should be inspected to determine if the crew oxygen mask stowage box unit is affected by the NPRM. If determined to be affected, the crew oxygen mask stowage box units should be removed and replaced with compliant crew oxygen mask stowage box units.

We partially agree with the request. We agree to designate units as “affected,” throughout the AD because that term adds clarity. We disagree to replace “if necessary” in the preamble of this supplemental NPRM with “as required,” because this phrase does not add clarity. We also disagree to add “or reworked” because we have revised paragraph (g)(1) of this AD to clarify that replacement crew oxygen mask stowage box units must be “new or serviceable.”

Request To Allow Rework at Repair Station and Return to Service

Avox requested that we revise the NPRM (75 FR 67637, November 3, 2010) to allow for removed crew oxygen mask stowage box units to be sent to an authorized repair station to be reworked and returned to service.

We partially agree with the request. We note that Intertechnique Service Bulletin MXP1/4-35-175, Revision 2, dated May 10, 2011, provides for return of the crew oxygen mask stowage box units to four authorized Intertechnique locations. However, we have not changed this supplemental NPRM in this regard.

Request To Include Inspection/Replacement of Spare Crew Oxygen Mask Stowage Box Units

Avox also requested that we revise the NPRM (75 FR 67637, November 3, 2010) to include an inspection and replacement of spare crew oxygen mask stowage box units. Avox explained that, for crew oxygen mask stowage box units located in storage as spares, it makes sense that these crew oxygen mask stowage box units should be inspected to determine if the unit is affected by the NPRM. If determined to be affected, the crew oxygen mask stowage box unit should be removed from storage and sent to an authorized repair station to be reworked and returned to service.

We disagree with the request. Section 39.3 of the Federal Aviation Regulations (14 CFR 39.3) does not permit ADs to be written against parts that are not installed on an airplane. Therefore, paragraph (h) of this supplemental NPRM does not allow an affected spare unit to be installed on any airplane. We have not changed this supplemental NPRM in this regard.

Request for Review of Airplane Maintenance Records Inspection and Spare Parts

Delta requested that we revise paragraphs (g) and (h) of the NPRM (75 FR 67637, November 3, 2010) to include the option of conducting a review of airplane or component maintenance records, or spare parts purchase records, to demonstrate that an airline does not operate or own any crew oxygen mask stowage box units that were manufactured in the date range listed in the service information in the NPRM. Delta proposed that this action be an acceptable method of compliance in lieu of a visual inspection to show that airplane or spare crew oxygen mask stowage box units are not affected by the NPRM. Delta reasoned that affected crew oxygen mask stowage box unit part numbers can be verified, as required by the NPRM, to be not applicable by a part and serial number inspection or records review, or by review of purchase order records that verify the date of manufacture does not fall in the affected manufacturing date range.

We disagree with the request to include a review of airplane maintenance records or spare parts purchase records. Section 39.3 of the Federal Aviation Regulations (14 CFR 39.3) does not permit ADs to be written against parts that are not installed on an airplane. Therefore, an AD cannot require that operators inspect, repair, or modify a “spare part.” Also, because of the rotability of these parts, a component level record review may not sufficiently address the required action in the supplemental NPRM. As the previous NPRM (75 FR 67637, November 3, 2010) specified, it is still acceptable to conduct a review of airplane maintenance records in lieu of the inspection in paragraph (g) of this supplemental NPRM, if the serial number of the crew oxygen mask stowage box unit can be conclusively determined from that review. Operators may apply for approval of an AMOC for these actions in accordance with the provisions of paragraph (i) of this supplemental NPRM, if sufficient data are submitted to substantiate that the change would provide an acceptable level of safety. We have not changed the supplemental NPRM in this regard.

FAA's Determination

We are proposing this supplemental NPRM because we evaluated all the relevant information and determined the unsafe condition described previously is likely to exist or develop in other products of these same type designs. Certain changes described above expand the scope of the original NPRM (75 FR 67637, November 3, 2010). As a result, we have determined that it is necessary to reopen the comment period to provide additional opportunity for the public to comment on this supplemental NPRM.

Proposed Requirements of the Supplemental NPRM

This supplemental NPRM would require accomplishing the actions specified in the service information described previously.

Costs of Compliance

We estimate that this proposed AD affects 40 airplanes of U.S. registry.

We estimate the following costs to comply with this proposed AD:

We have received no definitive data that would enable us to provide cost estimates for the on-condition actions specified in this proposed AD.

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),

(3) Will not affect intrastate aviation in Alaska, and

(4) 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.

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.