2010-16201. Airworthiness Directives; The Boeing Company Model 777 Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final rule.

SUMMARY:

We are adopting a new airworthiness directive (AD) for certain Model 777 airplanes. This AD requires inspecting the bolt, nut, and downstop of the slat track assembly to determine if the bolt, nut, or stops are missing and to determine if the thread protrusion of the bolt from the nut is within specified limits and parts are correctly installed, and related investigative and corrective actions if necessary. For certain airplanes, this AD also requires inspecting the slat cans at the outboard slat number 3 and 12 outboard main track locations for holes and wear damage, and corrective actions if necessary; and replacing the downstop hardware for the outboard slats number 3 and 12 outboard and inboard main track locations. This AD results from a report of a hole in the inboard main track slat can for outboard slat number 12 on a Model 777 airplane. The hole was caused when the bolt securing the downstop migrated out of the fitting and contacted the slat can. We are issuing this AD to detect and correct damage to the outboard slat main track slat cans, which can allow fuel leakage into the fixed wing leading edge in excess of the capacity of the draining system. Excess fuel leakage could result in an uncontained fire.

DATES:

This AD is effective August 17, 2010.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in the AD as of August 17, 2010.

ADDRESSES:

For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone [phone], extension 1; fax [phone]; e-mail [e-mail]; Internet https://www.myboeingfleet.com.

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 AD, the regulatory evaluation, any comments received, and other information. The address for the Docket Office (telephone [phone]) is the Document Management Facility, U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT:

Duong Tran, 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:

Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an airworthiness directive (AD) that would apply to certain Model 777 airplanes. That NPRM was published in the Federal Register on January 7, 2010 (75 FR 950). That NPRM proposed to require inspecting the bolt, nut, and downstop of the slat track assembly to determine if the bolt, nut, or stops are missing and to determine if the thread protrusion of the bolt from the nut is within specified limits and parts are correctly installed, and related investigative and corrective actions if necessary. For certain airplanes, that NPRM also proposed to require inspecting the slat cans at the outboard slat number 3 and 12 outboard main track locations for holes and wear damage, and corrective actions if necessary; and replacing the downstop hardware for the outboard slats number 3 and 12 outboard and inboard main track locations.

Relevant Service Information

We have reviewed Boeing Service Bulletin 777-57A0064, Revision 1, dated May 6, 2010. The NPRM referred to Boeing Alert Service Bulletin 777-57A0064, dated March 26, 2009, as the appropriate source of service information. Boeing Service Bulletin 777-57A0064, Revision 1, dated May 6, 2010, clarifies procedures, deletes a requirement, adds a note to allow a different fastener, revises an incorrect chamfer callout, and adds information that was published in Boeing Information Notice 777-57A0064 IN 01 and 777-57A0064 IN 02. Boeing Service Bulletin 777-57A0064, Revision 1, dated May 6, 2010, does not require additional work.

Comments

We gave the public the opportunity to participate in developing this AD. We considered the comments received from the commenters.

Support for the NPRM

Continental Airlines (Continental) supports the intent of the NPRM.

Request To Add Exception for Group 1 Airplanes

Boeing requests that we revise the NPRM to add a statement to paragraph (h) of the NPRM stating, “The outboard main track locations for slats 3 and 12 are excluded from the inspection defined in Table 3 of Boeing Alert Service Bulletin 777-57A0064, dated March 26, 2009.” Boeing states that, for Group 1 airplanes, the slat tracks do not penetrate into the wing fuel tank at these locations. Boeing also states that, for all Group 2 airplanes, this inspection is accomplished via Table 4 of Boeing Alert Service Bulletin 777-57A0064, dated March 26, 2009. Boeing Alert Service Bulletin 777-57A0064, dated March 26, 2009, states that for only Group 2 airplanes the outboard main track locations at slats 3 and 12 must be inspected. Boeing notes that it plans to issue a new revision to this service bulletin in June 2010 that contains this information.

We disagree with the commenter that such a revision is necessary. We have updated this final rule to refer to Boeing Service Bulletin 777-57A0064, Revision 1, dated May 6, 2010. Boeing Service Bulletin 777-57A0064, Revision 1, dated May 6, 2010, has corrected this information. We have added Boeing Service Bulletin 777-57A0064, Revision 1, dated May 6, 2010, as the appropriate source of service information for the actions required by this AD, including paragraph (g)(2) of this AD (in paragraph (g)(2) of the NPRM we referred to the original issue of the service bulletin for the compliance times but did not specifically reference the service bulletin as the applicable source of service information for doing the actions). We have also added paragraph (j) to this final rule to provide credit for actions done in accordance with Boeing Alert Service Bulletin 777-57A0064, dated March 26, 2009.

Request To Add Exception for Group 2 Airplanes

Boeing further requests that we revise paragraph (h) of the NPRM to state, “For airplanes defined as Group 2 in Boeing Alert Service Bulletin 777-57A0064, dated March 26, 2009, it is not necessary to perform the torque check on the downstop hardware for slats 3 and 12 as defined in Table 2 of Boeing Alert Service Bulletin 777-57A0064, dated March 26, 2009.” Boeing states that at locations where a fastener is to be replaced by subsequent instructions in Boeing Alert Service Bulletin 777-57A0064, dated March 26, 2009, a torque check is redundant and is not a technical requirement. Boeing states that the visual inspections are still in place to guarantee that damage caused by a loose fastener will be caught. Boeing also adds that Boeing Alert Service Bulletin 777-57A0064, dated March 26, 2009, specifies compliance times for the fastener replacement that are less than those for the torque check. Boeing notes that it plans to issue a new revision to this service bulletin in June 2010 that contains this information.

We agree with the commenter that such a revision is necessary. We have updated this final rule to refer to Boeing Service Bulletin 777-57A0064, Revision 1, dated May 6, 2010. However, we have added a new paragraph (i) to this final rule to clarify that this measurement is not necessary on slats 3 and 12. We have added Boeing Service Bulletin 777-57A0064, Revision 1, dated May 6, 2010, as the primary source of service information for accomplishing the actions required by this AD.

Request To Increase the Inspection Threshold to 12 Months

Continental requests that we revise the compliance time for the inspection from 6 months to 12 months after the effective date of the AD. Continental states that the current 6-month compliance time will not provide a practical period in which to complete the full inspection for its Model 777 fleet based on their maintenance schedule. Continental states that a 12-month threshold would not compromise the safety of the airplane because there are existing zonal inspection requirements in the referenced Maintenance Planning Document/Maintenance Review Board (MPD/MRB) tasks, discrepancies in the area of interest could be detected through the required routine inspections. Continental states that with a frequency of every 1,125 days from delivery, most affected airplanes should have had at least one inspection performed in accordance with the MPD/MRB tasks.

We disagree. Due to the urgent nature of a potential excessive fuel leakage, we do not find it appropriate to revise the inspection threshold. Furthermore, the MPD/MRB zonal inspection requirements are not intense enough to detect certain unobvious discrepancies (e.g., loose bolts and insufficient nut torque). However, under the provisions of paragraph (k) of this AD, we will consider requests for approval of an extension of the compliance time if sufficient data are submitted to substantiate that the extension would provide an acceptable level of safety. We have not changed the AD in regard to this issue.

Request To Clarify Requirements of Downstop Fitting Rework

EVA Airlines requests that we incorporate the information from Boeing Information Notice 777-57A0064 IN 01, dated May 28, 2009, which states that the chamfer for the −2 stop fitting in view B-B of Appendix A of Boeing Alert Service Bulletin 777-57A0064, dated March 26, 2009, should be “0.820−0.850 × 90 Degrees−120 Degrees” instead of “0.820−0.050 × 90 Degrees−120 Degrees.”

We agree that this information should be incorporated into the AD. Boeing Service Bulletin 777-57A0064, Revision 1, dated May 6, 2010, corrects this information. As stated previously, we have changed this AD to refer to Boeing Service Bulletin 777-57A0064, Revision 1, dated May 6, 2010, as the primary source of service information for accomplishing the actions required by this AD.

Conclusion

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. We also determined that these changes will not increase the economic burden on any operator or increase the scope of the AD.

Explanation of Change to Costs of Compliance

Since issuance of the NPRM, we have increased the labor rate used in the Costs of Compliance from $80 per work-hour to $85 per work-hour. The Costs of Compliance information, below, reflects this increase in the specified hourly labor rate.

Costs of Compliance

We estimate that this AD would affect 129 airplanes of U.S. registry. The following table provides the estimated costs for U.S. operators to comply with this AD.

Table—Estimated Costs

Action	Work hours	Average labor rate per hour	Parts	Cost per product	Number of U.S.- registered airplanes	Fleet cost
Inspection for Group 1 airplanes	39	$85	$0	$3,315 per inspection cycle	127	$421,005 per inspection cycle.
Inspection for Group 2 airplanes	55	85	0	4,675 per inspection cycle	2	9,350 per inspection cycle.
Replacement for Group 2 airplanes	8	85	9,267	9,947	2	19,894.

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

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.

You can find our regulatory evaluation and the estimated costs of compliance in the AD Docket.

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 FAA amends § 39.13 by adding the following new AD:

2010-14-13 The Boeing Company: Amendment 39-16358. Docket No. FAA-2009-1249; Directorate Identifier 2009-NM-100-AD.

Effective Date

(a) This airworthiness directive (AD) is effective August 17, 2010.

Affected Ads

(b) None.

Applicability

(c) This AD applies to The Boeing Company Model 777-200, -200LR, -300, and -300ER airplanes, certificated in any category; as identified in Boeing Service Bulletin 777-57A0064, Revision 1, dated May 6, 2010.

Subject

(d) Air Transport Association (ATA) of America Code 57: Wings.

Unsafe Condition

(e) This AD results from a report of a hole in the inboard main track slat can for outboard slat number 12 on a Model 777 airplane. The Federal Aviation Administration is issuing this AD to detect and correct damage to the outboard slat main track slat cans, which can allow fuel leakage into the fixed wing leading edge in excess of the capacity of the draining system. Excess fuel leakage could result in an uncontained fire.

Compliance

(f) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.

Inspect the Slat Main Track Stop Hardware and Measure the Torque of the Slat Main Track Stop Hardware

(g) At the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Service Bulletin 777-57A0064, Revision 1, dated May 6, 2010, except as required by paragraph (h) of this AD: Do the applicable actions specified in paragraphs (g)(1) and (g)(2) of this AD.

(1) For all airplanes: Do a detailed inspection of the slat main track stop hardware to determine if the bolt, nut, or stops are missing and to determine if the thread protrusion of the bolt from the nut is within specified limits, and do all applicable related investigative and corrective actions, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 777-57A0064, Revision 1, dated May 6, 2010, except as required by paragraph (i) of this AD. Do all applicable related investigative and corrective actions at the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Service Bulletin 777-57A0064, Revision 1, dated May 6, 2010, except as required by paragraph (h) of this AD.

(2) For airplanes identified as Group 2 airplanes in Boeing Service Bulletin 777-57A0064, Revision 1, dated May 6, 2010: Do a detailed inspection of the slat cans at the outboard slat number 3 and 12 outboard main track locations for holes and wear damage and do all applicable corrective actions, and replace the downstop hardware for the outboard slats number 3 and 12 outboard and inboard main track locations, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 777-57A0064, Revision 1, dated May 6, 2010. Do all applicable corrective actions at the applicable time specified in paragraph 1.E., “Compliance,” of Boeing Service Bulletin 777-57A0064, Revision 1, dated May 6, 2010.

Exception to the Service Bulletin

(h) Where Boeing Service Bulletin 777-57A0064, Revision 1, dated May 6, 2010, specifies a compliance time after the date on the service bulletin, this AD requires compliance within the specified compliance time after the effective date of this AD.

(i) Where Boeing Service Bulletin 777-57A0064, Revision 1, dated May 6, 2010, specifies measuring torque of the nuts of the slat main track stop hardware of slats 3 and 12, this AD does not require that action for Group 2 airplanes.

Credit for Actions Accomplished Previously

(j) Actions accomplished before the effective date of this AD according to Boeing Alert Service Bulletin 777-57A0064, dated March 26, 2009, are considered acceptable for compliance with the corresponding actions specified in this AD.

Alternative Methods of Compliance (AMOCs)

(k)(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. Send information to ATTN: Duong Tran, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone [phone]; fax [phone]. Or, e-mail information to [e-mail].

(2) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Before using any approved AMOC on any airplane to which the AMOC applies, notify your principal maintenance inspector (PMI) or principal avionics inspector (PAI), as appropriate, or lacking a principal inspector, your local Flight Standards District Office. The AMOC approval letter must specifically reference this AD.

(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.

Material Incorporated by Reference

(l) You must use Boeing Service Bulletin 777-57A0064, Revision 1, dated May 6, 2010, to do the actions required by this AD, unless the AD specifies otherwise.

(1) The Director of the Federal Register approved the incorporation by reference of this service information under 5 U.S.C. 552(a) and 1 CFR part 51.

(2) For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone [phone], extension 1; fax [phone]; e-mail [e-mail]; Internet https://www.myboeingfleet.com.

(3) You may review copies of the 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.

(4) You may also review copies of the service information that is incorporated by reference at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/​federal_​register/​code_​of_​federal_​regulations/​ibr_​locations.html.

Issued in Renton, Washington on June 21, 2010.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.