AD 2013-02-07

This AD is effective March 6, 2013.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in the AD as of March 6, 2013.

For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P.O. Box 3707, MC 2H-65, Seattle, WA 98124-2207; telephone 206-544-5000, extension 1; fax 206-766-5680; 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, WA. For information on the availability of this material at the FAA, call 425-227-1221.

Sarah Piccola, Aerospace Engineer, Cabin Safety and Environmental Systems Branch, ANM-150S, FAA, Seattle ACO, 1601 Lind Avenue SW., Renton, WA 98057-3356; phone: 425-917-6483; fax: 425-917-6590; email: sarah.piccola@faa.gov.

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that would apply to the specified products. That NPRM published in the Federal Register on February 27, 2012 (77 FR 11416). That NPRM proposed to require modifying COS boxes by installing new brackets, stiffeners, and hardware as needed.

We gave the public the opportunity to participate in developing this AD. The following presents the comments received on the proposal (77 FR 11416, February 27, 2012) and the FAA's response to each comment. United Airlines and two private citizens support the NPRM. Aviation Partners Boeing stated that the installation of winglets per Supplemental Type Certificate (STC) ST00830SE does not affect the actions specified in the NPRM or Boeing Special Attention Service Bulletin 737-25-1641, Revision 1, dated August 8, 2011.

American Airlines requested that we extend the compliance time in the NPRM (77 FR 11416, February 27, 2012) from 60 months to 72 months to align with the heavy maintenance program driven by the Model 737 Maintenance Review Board.

We do not agree with extending the compliance time to 72 months, because an operator has experienced an event where the COS box did not remain fully attached. An increase in compliance time is not in the interest of public safety. We have not changed the final rule regarding this issue. In developing an appropriate compliance time for this action, we considered the safety implications, parts availability, and normal maintenance schedules for the timely accomplishment of the modification. In consideration of these items, as well as the reports where the COS box did not remain fully attached, we have determined that a 60-month compliance time will ensure an acceptable level of safety and allow the modifications to be done during scheduled maintenance intervals for most affected operators. We have not changed the AD in this regard.

Boeing requested that we clarify the language of the NPRM (77 FR 11416, February 27, 2012) and replace the words “other products of this same type design” in the paragraph “FAA's Determination,” with the words “the Boeing 737 Next Generation (737NG) airplane prior to L/N 3518 excluding Boeing Sky Interior (BSI).” Boeing considered the existing language too general and confusing for operators.

We disagree with changing the AD. This standard language contained under “FAA's Determination” is in all proposed airworthiness directives to show adherence to Part 39 of the Federal Aviation Regulations (14 CFR 39), and is not restated in the final rule.

Arkefly Airlines suggested that Boeing give the option to reduce the maximum load to a load that would meet the 9 g requirement without modification. The commenter suggested this could be incorporated by installing a placard with the new (reduced) maximum load.

We disagree because the customer COS box configuration has already been taken into account. This AD addresses optional COS boxes. These boxes typically contain life rafts, palletized equipment, or miscellaneous equipment. Boeing based its original design on the customer configurations and has determined that the design does not meet the 9 g load requirement. We have not changed the AD in this regard.

The previous NPRM (77 FR 11416, February 27, 2012) referred to Boeing Special Attention Service Bulletin 737-25-1641, Revision 1, dated August 8, 2011, as the appropriate source of service information for accomplishing the required actions. Since we issued the previous NPRM, we have reviewed Boeing Special Attention Service Bulletin 737-25-1641, Revision 2, dated November 20, 2012, which made minor changes to part numbering of materials; added no additional work required by Boeing Special Attention Service Bulletin 737-25-1641, Revision 1, dated August 8, 2011; and both added and deleted airplanes from Group 2 airplanes. The added airplanes are not in the U.S. registry. We revised paragraphs (c) and (g) of this AD to refer to Boeing Special Attention Service Bulletin 737-25-1641, Revision 2, dated November 20, 2012, and revised paragraph (h) to give credit for work performed before the effective date of the AD using Boeing Special Attention Service Bulletin 737-25-1641, Revision 1, dated August 8, 2011.

We reviewed the relevant data, considered the comments received, and determined that air safety and the public interest require adopting the AD with the changes described previously and minor editorial changes. We have determined that these minor changes:

• Are consistent with the intent that was proposed in the NPRM (77 FR 11416, February 27, 2012) for correcting the unsafe condition; and

• Do not add any additional burden upon the public than was already proposed in the NPRM (77 FR 11416, February 27, 2012).

We estimate that this AD affects 526 airplanes of U.S. registry.

We estimate the following costs to comply with this AD:

According to the manufacturer, some of the costs of this AD may be covered under warranty, thereby reducing the cost impact on affected individuals. We do not control warranty coverage for affected individuals. As a result, we have included all costs in our cost estimate.

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.

This 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.

For the reasons discussed above, I certify that this AD:

(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),

(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.

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows:

1. The authority citation for part 39 continues to read as follows:

2. The FAA amends § 39.13 by adding the following new airworthiness directive (AD):