2012-22392. Airworthiness Directives; The Boeing Company Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

We propose to adopt a new airworthiness directive (AD) for all The Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes. This proposed AD was prompted by reports of an incorrect procedure used to apply the wear and corrosion protective surface coating to attach pins of the horizontal stabilizer rear spar. This proposed AD would require inspecting to determine the part number of the attach pins of the horizontal stabilizer rear spar, and replacing certain attach pins with new, improved attach pins. We are proposing this AD to prevent premature failure of the attach pins, which could cause reduced structural integrity of the horizontal stabilizer to fuselage attachment, resulting in loss of control of the airplane.

DATES:

We must receive comments on this proposed AD by October 29, 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: [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: Deliver to Mail address above 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, WA 98124-2207; telephone [phone], extension 1; fax [phone]; 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.

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: [phone]) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

Nancy Marsh, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue SW., Renton, WA 98057-3356; phone [phone]; fax [phone]; email [e-mail].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or arguments about this proposal. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2012-0933; Directorate Identifier 2012-NM-107-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 of pins with an unapproved surface coating installed at the horizontal stabilizer rear spar attach locations. An incorrect procedure to apply the wear and corrosion protective surface coating was used by a supplier. The pins were installed on new airplanes and were also distributed by Boeing Spares.

A large number of the part number (P/N) 180A1612-3 and 180A1612-4 pins that were supplied to Boeing between June 30, 2006, and January 31, 2008, have an unapproved surface coating. These pins were distributed by Boeing Spares and were installed on most new airplanes delivered between August 2006 and July 2008. These pins could also have been installed as terminating action for Boeing Service Bulletin 737-55-1086 (specified in AD 2004-05-19, Amendment 39-13514 (69 FR 10921, March 9, 2004; corrected April 13, 2004 (69 FR 19313)), or during maintenance as specified in Section 9 of the Boeing 737-600/700/700C/800/900/900ER Maintenance Planning Document. No practical non-destructive inspection procedures exist to determine whether the pins have an approved or unapproved surface coating. This condition, if not corrected, could result in premature failure of the attach pins, which could cause reduced structural integrity of the horizontal stabilizer to fuselage attachment, resulting in loss of control of the airplane.

Relevant Service Information

We reviewed Boeing Special Attention Service Bulletin 737-55-1093, dated April 9, 2012. The service information describes procedures for replacing certain attach pins of the horizontal stabilizer rear spar with new, improved attach pins.

FAA's Determination

We are proposing this AD because we evaluated all the relevant information and determined the unsafe condition described previously is likely to exist or develop in other products of the same type design.

Proposed AD Requirements

This proposed AD would require inspecting to determine the part number of the attach pins of the horizontal stabilizer rear spar, and replacing certain attach pins with new, improved attach pins.

Costs of Compliance

We estimate that this proposed AD affects 1,050 airplanes of U.S. registry.

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

Estimated costs

Action	Labor cost	Parts cost	Cost per product	Cost on U.S. operators
Inspection and attach pin replacement	39 work-hours × $85 per hour = $3,315	Up to $6,312	$9,627	Up to $10,108,350.

According to the manufacturer, some of the costs of this proposed 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.

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.

§ 39.13

[Amended]

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

The Boeing Company: Docket No. FAA-2012-0933; Directorate Identifier 2012-NM-107-AD.

(a) Comments Due Date

We must receive comments by October 29, 2012.

(b) Affected ADs

None.

(c) Applicability

This AD applies to all The Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes; certificated in any category.

(d) Subject

Joint Aircraft System Component (JASC)/Air Transport Association (ATA) of America Code 55, Stabilizers.

(e) Unsafe Condition

This AD was prompted by reports of an incorrect procedure used to apply the wear and corrosion protective surface coating to attach pins of the horizontal stabilizer rear spar. We are issuing this AD to prevent premature failure of the attach pins, which could cause reduced structural integrity of the horizontal stabilizer to fuselage attachment, resulting in loss of control of the airplane.

(f) Compliance

Comply with this AD within the compliance times specified, unless already done.

(g) Part Number (P/N) Inspection

For airplanes having line numbers 1 through 3534 inclusive: Before the accumulation of 56,000 total flight cycles, or within 3,000 flight cycles after the effective date of this AD, whichever occurs later, inspect to determine the part number of the attach pins of the horizontal stabilizer rear spar. A review of airplane maintenance records is acceptable in lieu of this inspection if the part number of the attach pin can be conclusively determined from that review.

(h) Replacement

If, during the inspection required by paragraph (g) of this AD, any attach pin of the horizontal stabilizer rear spar has P/N 180A1612-3 or 180A1612-4, before further flight, replace with a new attach pin having P/N 180A1612-7 or 180A1612-8, respectively, in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-55-1093, dated April 9, 2012.

(i) Parts Installation Prohibition

For all airplanes: As of the effective date of this AD, no person may install an attach pin of the horizontal stabilizer rear spar having P/N 180A1612-3 or 180A1612-4, on any airplane.

(j) Alternative Methods of Compliance (AMOCs)

(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. In accordance with 14 CFR 39.19, send your request to your principal inspector or local Flight Standards District Office, as appropriate. If sending information directly to the manager of the ACO, send it to the attention of the person identified in the Related Information section of this AD. Information may be emailed to: [e-mail].

(2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/certificate holding district office.

(3) An AMOC that provides an acceptable level of safety may be used for any repair required by this AD if it is approved by the Boeing Commercial Airplanes Organization Designation Authorization (ODA) that has been authorized by the Manager, Seattle ACO, to make those findings. For a repair method to be approved, the repair must meet the certification basis of the airplane, and the approval must specifically refer to this AD.

(k) Related Information

(1) For more information about this AD, contact Nancy Marsh, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue SW., Renton, WA 98057-3356; phone [phone]; fax [phone]; email [e-mail].

(2) 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 [phone], extension 1; fax [phone]; 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.

Issued in Renton, Washington, on August 31, 2012.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.