E6-19797. Airworthiness Directives; Boeing Model 767 Airplanes

AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT).

ACTION:

Final rule.

SUMMARY:

The FAA is adopting a new airworthiness directive (AD) for all Boeing Model 767 airplanes. This AD requires repetitive detailed and high frequency eddy current (HFEC) inspections of the station (STA) 1809.5 bulkhead for cracking and corrective actions if necessary. This AD results from fatigue cracks found in the forward outer chord and horizontal inner chord at STA 1809.5. We are issuing this AD to detect and correct cracking in the bulkhead structure at STA 1809.5, which could result in failure of the bulkhead structure for carrying the flight loads of the horizontal stabilizer, and consequent loss of controllability of the airplane.

DATES:

This AD becomes effective January 2, 2007.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in the AD as of January 2, 2007.

ADDRESSES:

You may examine the AD docket on the Internet at http://dms.dot.gov or in person at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, Washington, DC.

Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207, for service information identified in this AD.

FOR FURTHER INFORMATION CONTACT:

Wayne Lockett, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Examining the Docket

You may examine the airworthiness directive (AD) docket on the Internet at http://dms.dot.gov or in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone [phone]) is located on the plaza level of the Nassif Building at the street address stated in the ADDRESSES section.

Discussion

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that would apply to all Boeing Model 767 airplanes. That NPRM was published in the Federal Register on May 22, 2006 (71 FR 29275). That NPRM proposed to require repetitive detailed and high frequency eddy current (HFEC) inspections of the station (STA) 1809.5 bulkhead for cracking and corrective actions if necessary.

Comments

We provided the public the opportunity to participate in the development of this AD. We have considered the comments received.

Support for the NPRM

Boeing and Continental Airlines agree with the NPRM, while the Air Transport Association (ATA) agrees with the intent of the NPRM.

Request To Add Terminating Action

The Air Transport Association (ATA) of America, on behalf of Delta Airlines, requests that we revise the NPRM to allow accomplishment of certain actions in the applicable Boeing structural repair manual (SRM) as terminating action for the repetitive inspections. Although the NPRM proposes to require accomplishing the SRM repair only if cracking is found, Delta would like to accomplish the SRM repair at its next heavy maintenance visit, regardless of inspection findings. Delta also requests that, if the SRM repair is accomplished before finding any cracking, certain actions called out in the SRM, such as cutting out damaged areas and installing filler, not be required as part of the terminating action.

We agree to revise the requirements of this AD. The repetitive actions required by this AD may be terminated by accomplishing certain actions in Repair 9 or Repair 10, both dated April 15, 2006, of Chapter 53-80-08 of Boeing 767-200 SRM, Document D634T201; Boeing 767-300 SRM, Document D634T210; Boeing 767-300F SRM, Document D634T215; or Boeing 767-400 SRM, Document D634T225; as applicable. Operators should note that to maintain the type certification of the airplane after accomplishing the SRM repair, the supplemental inspections specified in the SRM must also be accomplished. These supplemental inspections are outside of the requirements of this AD. We have added a new paragraph (h) to this AD to provide an optional terminating action.

Repair 9 describes procedures for repairing a forward outer chord between S-4 and S-8 and doing repetitive supplemental inspections. The supplemental inspections are a (1) Detailed inspection of the repair angles, fillers, skin bulkhead web and visible parts of the bulkhead outer chord, and a 2.0-inch-wide zone around the repair internally and externally and (2) low frequency eddy current inspection of the forward outer chord internally through a certain angle. Repair 10 describes procedures for repairing a horizontal inner chord at approximately water line (WL) 257 and buttock line (BL) 28 and doing repetitive supplemental inspections. The supplemental inspection is a detailed inspection of the repair angles, fillers, visible parts of the bulkhead inner chord, adjacent structure, and a 2.0-inch-wide zone around the repair internally.

Request for Credit for Previously Accomplished Repairs

The ATA, on behalf of Delta Airlines, also requests that we add a note stating that repairs accomplished previously in accordance with the applicable SRM, as referenced by Boeing Alert Service Bulletin 767-53A0131, dated March 30, 2006, terminate the requirements of this AD. Delta states that neither the NPRM nor the service bulletin addresses SRM repairs accomplished before the effective date of this AD. Delta also states if no note is added to the NPRM, an operator may feel obliged to obtain an alternative method of compliance (AMOC) for previously accomplished repairs.

We agree to provide credit for a previously accomplished repair if the repair was done after finding cracking. Accomplishment of Repair 9 for a forward outer chord or Repair 10 for a horizontal inner chord before the effective date of this AD, in accordance with the applicable SRM, is acceptable for compliance with the inspections and corrective actions required by paragraph (f) of this AD for that area only. Operators must accomplish all of the actions in Repair 9 or Repair 10, as applicable. We have added a new paragraph (i) to this AD to provide credit.

Request To Provide Repair Data

The ATA, on behalf of US Airways, requests that, before we issue the AD, Boeing either revise Alert Service Bulletin 767-53A0131 to include instructions for repairing cracking, or include them in the SRM. US Airways states that the service bulletin does not contain instructions for repairing cracking found in the fuselage skin; instead, the service bulletin specifies contacting Boeing for repair instructions. (The service bulletin and referenced SRMs only contain instructions to repair cracking found in a forward outer chord or horizontal inner chord.) The commenter states that providing the FAA-approved repair data will reduce the administrative burden between an operator and the Boeing Commercial Airplanes Delegation Option Authorization Organization, regarding repair approvals. The commenter also states that providing the repair data would expedite repairs and return airplanes to revenue service in a timely manner.

We do not agree to publish FAA-approved repair data for cracking found in the fuselage skin. We acknowledge that the service bulletin and applicable SRM do not contain instructions to repair fuselage skin cracking. However, the time needed to develop and approve fuselage skin repairs would delay addressing the unsafe condition in the forward outer chord and horizontal inner chord of the STA 1809.5 bulkhead. To delay this action would be inappropriate, since we have determined that an unsafe condition exists and that inspections and repair, if necessary, must be conducted to ensure continued safety. We have not revised this AD in this regard.

Conclusion

We have carefully reviewed the available data, including the comments received, and determined that air safety and the public interest require adopting the AD with the changes described previously. We have determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.

Costs of Compliance

There are about 903 airplanes of the affected design in the worldwide fleet. This AD affects about 405 airplanes of U.S. registry. The required actions take about 12 work hours per airplane, at an average labor rate of $80 per work hour. Based on these figures, the estimated cost of the AD for U.S. operators is $388,800, or $960 per airplane, per inspection cycle.

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 have determined that 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); 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.

We prepared a regulatory evaluation of the estimated costs to comply with this AD and placed it in the AD docket. See the ADDRESSES section for a location to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

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

Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 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 Federal Aviation Administration (FAA) amends § 39.13 by adding the following new airworthiness directive (AD):

2006-24-04 Boeing: Amendment 39-14833. Docket No. FAA-2006-24814; Directorate Identifier 2006-NM-093-AD.

Effective Date

(a) This AD becomes effective January 2, 2007.

Affected ADs

(b) None.

Applicability

(c) This AD applies to all Boeing Model 767-200, -300, -300F, and -400ER series airplanes, certificated in any category.

Unsafe Condition

(d) This AD results from fatigue cracks found in the forward outer chord and horizontal inner chord at station (STA) 1809.5. We are issuing this AD to detect and correct cracking in the bulkhead structure at STA 1809.5, which could result in failure of the bulkhead structure for carrying the flight loads of the horizontal stabilizer, and consequent loss of controllability of the airplane.

Compliance

(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.

Repetitive Inspections and Corrective Actions

(f) Before the accumulation of 15,000 total flight cycles, or within 3,000 flight cycles after the effective date of this AD, whichever is later: Do the detailed and high frequency eddy current (HFEC) inspections for cracking as specified in Parts 1, 2, 3, and 4 of the Accomplishment Instructions of Boeing Alert Service Bulletin 767-53A0131, dated March 30, 2006; and do all corrective actions before further flight; by accomplishing all the actions specified in the Accomplishment Instructions of Boeing Alert Service Bulletin 767-53A0131, dated March 30, 2006, except as provided by paragraph (g) of this AD. Repeat the inspections thereafter at intervals not to exceed 6,000 flight cycles. Accomplishing the corrective action for the inspections specified in Part 1, 2, 3, or 4 of the service bulletin, as applicable, terminates the repetitive inspections for that area only.

Exception to Service Bulletin

(g) If any cracking is found in the skin or in any structure other than the forward outer chord or horizontal inner chord, during any inspection required by this AD, and Boeing Alert Service Bulletin 767-53A0131, dated March 30, 2006, specifies to contact Boeing for appropriate action: Before further flight, repair the cracking using a method approved in accordance with the procedures specified in paragraph (j) of this AD.

Optional Terminating Action

(h) If no cracking is found during the most recent detailed and HFEC inspections for a specified area as required by paragraph (f) of this AD: Modification of a specified area according to a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, terminates the repetitive inspections required by paragraph (f) of this AD for that area only. For a forward outer chord, one approved method is accomplishment of the actions in Steps 4.A through 4.C and 4.G through 4.P of Repair 9, dated April 15, 2006, of Chapter 53-80-08 of the Boeing 767-200 Structural Repair Manual (SRM), Document D634T201; Boeing 767-300 SRM, Document D634T210; Boeing 767-300F SRM, Document D634T215; or Boeing 767-400 SRM, Document D634T225; as applicable. For a horizontal inner chord, one approved method is accomplishment of the actions in Steps 4.A, 4.B, and 4.F through 4.P of Repair 10, dated April 15, 2006, of Chapter 53-80-08 of the Boeing 767-200 SRM, Document D634T201; Boeing 767-300 SRM, Document D634T210; Boeing 767-300F SRM, Document D634T215; or Boeing 767-400 SRM, Document D634T225; as applicable.

Credit for Previously Accomplished Repairs

(i) Repair of a forward outer chord done before the effective date of this AD in accordance with Repair 9, dated April 15, 2006, of Chapter 53-80-08 of the Boeing 767-200 SRM, Document D634T201; Boeing 767-300 SRM, Document D634T210; Boeing 767-300F SRM, Document D634T215; or Boeing 767-400 SRM, Document D634T225; as applicable; is acceptable for compliance with the requirements of paragraph (f) of this AD for that area only. Repair of a horizontal inner chord before the effective date of this AD in accordance with Repair 10, dated April 15, 2006, of Chapter 53-80-08 of the Boeing 767-200 SRM, Document D634T201; Boeing 767-300 SRM, Document D634T210; Boeing 767-300F SRM, Document D634T215; or Boeing 767-400 SRM, Document D634T225; as applicable; is acceptable for compliance with the requirements of paragraph (f) of this AD for that area only.

Alternative Methods of Compliance (AMOCs)

(j)(1) The Manager, Seattle ACO, FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.

(2) Before using any AMOC approved in accordance with § 39.19 on any airplane to which the AMOC applies, notify the appropriate principal inspector in the FAA Flight Standards 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 an Authorized Representative for the Boeing Commercial Airplanes Delegation Option Authorization Organization, who 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.

Material Incorporated by Reference

(k) You must use Boeing Alert Service Bulletin 767-53A0131, dated March 30, 2006, to perform the actions that are required by this AD, unless the AD specifies otherwise. The Director of the Federal Register approved the incorporation by reference of this document in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207, for a copy of this service information. You may review copies at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., Room PL-401, Nassif Building, Washington, DC; on the Internet at http://dms.dot.gov; or at the National Archives and Records Administration (NARA). For information on the availability of this material at the NARA, call [phone], or go to http://www.archives.gov/​federal_​register/​code_​of_​federal_​regulations/​ibr_​locations.html.

Issued in Renton, Washington, on November 9, 2006.

Kalene C. Yanamura,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.