E6-11413. Airworthiness Directives; Boeing Model 767 Airplanes

AGENCY:

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

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for certain Boeing Model 767 airplanes. This proposed AD would require repetitive inspections for cracking of the wing skin, and related investigative/corrective actions if necessary. This proposed AD results from reports of cracks found in the lower wing skin originating at the forward tension bolt holes of the aft pitch load fitting. We are proposing this AD to detect and correct such cracking in the lower wing skin for the forward tension bolt holes at the aft pitch load fitting, which could result in a fuel leak and reduced structural integrity of the airplane.

DATES:

We must receive comments on this proposed AD by September 5, 2006.

ADDRESSES:

Use one of the following addresses to submit comments on this proposed AD.

• DOT Docket Web site: Go to http://dms.dot.gov and follow the instructions for sending your comments electronically.
• Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
• Mail: Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street SW., Nassif Building, room PL-401, Washington, DC 20590.
• Fax: [phone].
• Hand Delivery: Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

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

FOR FURTHER INFORMATION CONTACT:

Steven C. Fox, Senior Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to submit any relevant written data, views, or arguments regarding this proposed AD. Send your comments to an address listed in the ADDRESSES section. Include the docket number “FAA-2006-25390; Directorate Identifier 2005-NM-224-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments received by the closing date and may amend the proposed AD in light of those comments.

We will post all comments we receive, without change, to http://dms.dot.gov,, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this proposed AD. Using the search function of that Web site, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you may visit http://dms.dot.gov.

Examining the Docket

You may examine the 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 DOT street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after the Docket Management System receives them.

Discussion

We have received reports indicating that cracks have been found in the lower wing skin, originating at the forward tension bolt holes of the aft pitch load fitting, on several Boeing Model 767-200 series airplanes. The cracks varied in length from 0.04 to 0.63 inch, though none extended through the thickness of the wing skin. Crack initiation has been attributed to skin stresses due to wing bending combined with the high bolt clamp-up load. Cracking at the forward tension bolt holes, common to the aft pitch fitting and backup fitting, is caused by fatigue. Cracking in the lower wing skin for the forward tension bolt holes at the aft pitch load fitting, if not detected and corrected, could result in a fuel leak and reduced structural integrity of the airplane.

Relevant Service Information

We have reviewed Boeing Alert Service Bulletin (ASB) 767-57A0097, dated September 29, 2005. The ASB describes procedures for the following:

• Doing external high frequency eddy current (HFEC) or dye penetrant inspections for cracking of the left and right wing surfaces at the aft pitch load fitting, and doing any corrective action as necessary. The corrective action includes reworking the wing surface to remove all indication of cracking in accordance with Part 2 of the Accomplishment Instructions. The service bulletin advises that, if any indication of cracking cannot be completely removed, the corrective action is repairing the cracking with a freeze plug in accordance with Part 3 of the Accomplishment Instructions. If the repair cannot be accomplished within the limits specified in Part 3, the service bulletin advises that the corrective action is to contact the manufacturer for repair instructions.
• Doing an open hole HFEC inspection for cracking and rework (including installing new tension bolts) of the forward tension bolt holes at the aft pitch load fitting, and doing any corrective action as necessary. The corrective action includes oversizing the fastener hole within certain limits. If cracking is outside the limits specified in Part 2 of the Accomplishment Instructions, the service bulletin advises to repair the cracking in accordance with Part 3 of the accomplishment instructions. If repair is necessary outside the limits specified in Part 3, the service bulletin advises that the corrective action is to contact the manufacturer.
• Doing an internal HFEC inspection and external HFEC inspections of the left and right wing surfaces for any cracking; and doing any corrective action as necessary, which includes reworking the wing surface to remove all indication of cracking in accordance with Part 2 of the Accomplishment Instructions. If any indication of cracking cannot be completely removed, the service bulletin advises that the corrective action is repairing the cracking with a freeze plug in accordance with Part 3 of the Accomplishment Instructions. If the repair cannot be accomplished within the limits specified in Part 3 of the Accomplishment Instructions, the corrective action is to contact the manufacturer for repair instructions.

The ASB also specifies certain actions and compliance times for airplanes on which the actions described in the following Boeing Service Bulletins have been accomplished: 767-54-0080, 767-54-0081, or 767-54-0082.

Accomplishing the actions specified in the service information is intended to adequately address the unsafe condition.

Related ADs

We have previously issued the following two ADs that require modifying the nacelle strut and wing structure: AD 2000-19-09, amendment 39-11910 (65 FR 58641, October 2, 2000); and AD 2004-16-12, amendment 39-13768 (69 FR 51002, August 17, 2004). Those two ADs reference, as applicable, Boeing Service Bulletins 767-54-0080, Revision 1, dated May 9, 2002; 767-54-0081, dated July 29, 1999; and 767-54-0082, dated October 28, 1999, as appropriate sources of service information.

FAA's Determination and Requirements of the Proposed AD

We have evaluated all pertinent information and identified an unsafe condition that is likely to exist or develop on other airplanes of this same type design. For this reason, we are proposing this AD, which would require accomplishing the actions specified in the service information described previously, except as discussed under “Differences Between the Proposed AD and the ASB.”

Differences Between the Proposed AD and the ASB

The ASB specifies to contact the manufacturer for instructions on how to repair certain conditions, but this proposed AD would require repairing those conditions in one of the following ways:

• Using a method that we approve; or
• Using data that meet the certification basis of the airplane, and that have been approved by an Authorized Representative for the Boeing Commercial Airplanes Delegation Option Authorization Organization whom we have authorized to make those findings.

Additionally, the ASB is not clear regarding what repair actions should be taken if cracking is found during an inspection accomplished in accordance with Part 1 of the ASB. We have determined that inspections accomplished in accordance with Part 1 of the ASB are intended to find a crack that is long enough to go beyond the edge of the fitting. Since rework specified in Part 2 of the ASB consists of a small oversize of the holes, any cracking found during the Part 1 inspection would be outside the limits of the repairs in Part 2 of the ASB. This proposed AD would require that any cracking found outside the limits of Part 1 of the ASB be repaired in accordance with freeze plug repair specified in Part 3 of the ASB. Any cracking found outside the limits of Part 3 of the ASB must be repaired in accordance with a method approved by the Manager of the Seattle ACO. Boeing has agreed with this clarification.

Operators should also note that, although the Accomplishment Instructions of the referenced service bulletin describe procedures for submitting a report of damage found, this proposed AD would not require that action.

Costs of Compliance

There are about 918 airplanes of the affected design in the worldwide fleet, and about 387 airplanes on the U.S. Registry. The following table provides the estimated costs, at an average labor rate of $80 per hour, for U.S. operators to comply with this proposed AD.

Estimated Costs

Action	Work hours	Parts	Cost per airplane	Fleet cost
Inspection, per inspection cycle (Part 1)	8	None	$640	$247,680.
Inspection, rework, and bolt installation (Part 2)	8	Between $303 and $12,716	Between $943 and $13,356	Between $364,941, and $5,168,772.
Repetitive Inspections for certain airplanes (Part 4)	4	None	$320, per inspection cycle	$123,840, 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 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 that the 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.

We prepared a regulatory evaluation of the estimated costs to comply with this proposed 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
• 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 Federal Aviation Administration (FAA) amends § 39.13 by adding the following new airworthiness directive (AD):

Boeing: Docket No. FAA-2006-25390; Directorate Identifier 2005-NM-224-AD.

Comments Due Date

(a) The FAA must receive comments on this AD action by September 5, 2006.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Boeing Model 767-200, -300, -300F, and -400ER series airplanes, certificated in any category; as identified in Boeing Alert Service Bulletin 767-57A0097, dated September 29, 2005.

Unsafe Condition

(d) This AD results from reports of cracks found in the lower wing skin originating at the forward tension bolt holes of the aft pitch load fitting. We are issuing this AD to detect and correct such cracking in the lower wing skin for the forward tension bolt holes at the aft pitch load fitting, which could result in a fuel leak and reduced structural integrity 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.

External Inspections of the Wing Skin

(f) For airplanes specified as Group 1, Configuration 1, 2, 3, or 6; Group 2, Configuration 1, 2, 3, or 6; and Group 3, Configuration 1 or 3, as specified in Boeing Alert Service Bulletin (ASB) 767-57A0097, dated September 29, 2005: Prior to the accumulation of 10,000 total flight cycles, or within 3,000 flight cycles after the effective date of this AD, whichever occurs later, perform the detailed inspection and the external high frequency eddy current (HFEC) or dye penetrant inspections for cracking as specified in Part 1 of the Accomplishment Instructions of the ASB. Repeat at intervals not to exceed 3,000 flight cycles until the requirements of paragraph (g) or (i) of this AD are accomplished.

Internal Inspections of the Wing Skin

(g) For airplanes specified in paragraphs (g)(1) and (g)(2) of this AD: Perform the bolt open-hole inspections for cracking in accordance with Part 2 of the Accomplishment Instructions of Boeing ASB 767-57A0097, dated September 29, 2005, at the times specified in paragraphs (g)(1) or (g)(2) of this AD, as applicable, until the requirements of paragraphs (h) or (i) of this AD are accomplished.

(1) For airplanes on which the actions specified in Boeing SB 767-54-0080, Revision 1, dated May 9, 2002; 767-54-0081, dated July 29, 1999; or 767-54-0082, dated October 28, 1999, have been accomplished prior to the effective date of this AD: Within 16,500 flight cycles after accomplishment of Boeing SB 767-54-0080, 767-54-0081, or 767-54-0082, or within 3,000 flight cycles after the effective date of this AD, whichever occurs later. Repeat the inspections at intervals not to exceed 16,500 flight cycles.

(2) For airplanes on which the actions specified in Boeing Service Bulletin 767-54-0080, Revision 1, dated May 9, 2002; 767-54-0081, dated July 29, 1999; and 767-54-0082, dated October 28, 1999, have not been accomplished as of the effective date of this AD: Before the accumulation of 20,000 total flight cycles, or within 72 months after the effective date of this AD, whichever occurs later. Repeat the inspections at intervals not to exceed 16,500 flight cycles.

Acceptable Method of Compliance with Paragraph (g) of this AD

(h) For all airplanes, regardless of whether Boeing Service Bulletins 767-54-0080, Revision 1, dated May 9, 2002; 767-54-0081, dated July 29, 1999; or 767-54-0082, dated October 28, 1999, have been accomplished: Accomplishing the inspections specified in Part 1 of the Accomplishment Instructions of Boeing ASB 767-57A0097, dated September 29, 2005, within 3,000 flight cycles after the accomplishment of the most recent inspection done in accordance with paragraph (g) of this AD (Part 2 of the Accomplishment Instructions of the ASB), and repeating the Part 1 inspections at intervals not to exceed 3,000 flight cycles is an acceptable method of compliance with the repetitive inspection requirements of paragraph (g) of this AD.

Repair of Cracking

(i) If cracking is found during any inspection required by paragraph (f), (g), or (h) of this AD: Before further flight, accomplish the freeze plug repair in accordance with Part 3 of Boeing ASB 767-57A0097, dated September 29, 2005. If any cracking is outside the limits specified in Part 3 of the ASB, before further flight, repair in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO). For airplanes on which the repair specified in paragraph (i) of this AD has been accomplished on only one wing, continue the inspections specified by paragraphs (f) and (g) of this AD on the wing on which the repair has not been accomplished, until the freeze plug repair specified in paragraph (i) of this AD has been accomplished on both wings.

Repetitive Inspections Required After Accomplishing Paragraph (i) of this AD

(j) After accomplishment of the requirements of paragraph (i) of this AD, perform the repetitive inspections specified in paragraphs (j)(1) and (j)(2) of this AD at the times specified.

(1) Prior to the accumulation of 37,500 total flight cycles, or within 18 months after accomplishment of the freeze plug repair specified in Part 3 of the Accomplishment Instructions of Boeing ASB 767-57A0097, dated September 29, 2005, whichever occurs later: Accomplish the external inspections specified in Part 1 of the Accomplishment Instructions of Boeing ASB 767-57A0097, dated September 29, 2005. If any cracking is found during any inspection required by this paragraph, before further flight, repair in accordance with a method approved by the Manager, Seattle ACO. Thereafter, repeat the external inspections at intervals not to exceed 3,000 flight cycles.

(2) Prior to the accumulation of 37,500 total flight cycles, or within 72 months after accomplishment of the freeze plug repair specified Part 3 of the Accomplishment Instructions of Boeing ASB 767-57A0097, dated September 29, 2005, whichever occurs later: Perform an internal HFEC for cracking, in accordance with Part 4 of the Accomplishment Instructions of Boeing ASB 767-57A0097, dated September 29, 2005. If any cracking is found during any inspection required by this paragraph, before further flight, repair in accordance with a method approved by the Manager, Seattle ACO. Repeat the inspections at intervals not to exceed 12,000 flight cycles.

Repair of Certain Cracking

(k) If any cracking is found during any inspection required by this AD, and the bulletin 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 (m) of this AD.

No Reporting Requirement

(l) Although Boeing Alert Service Bulletin 767-57A0097, dated September 29, 2005, specifies to submit certain information to the manufacturer, this AD does not include that requirement.

Alternative Methods of Compliance (AMOCs)

(m)(1) The Manager, Seattle ACO, 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.

Issued in Renton, Washington, on July 7, 2006.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.