02-1452. Airworthiness Directives; Boeing Model 767 Series Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule.

SUMMARY:

This amendment supersedes an existing airworthiness directive (AD), applicable to certain Boeing Model 767 series airplanes, that currently requires inspections to detect cracking and corrosion of the aft trunnion of the outer cylinder of the main landing gear (MLG) and various follow-on actions. That AD also currently requires termination of the inspections by repairing the outer cylinder and installing new aft trunnion bushings. This amendment prohibits the use of a particular corrosion inhibiting compound during accomplishment of the terminating action. This action is necessary to prevent the collapse of the MLG due to stress corrosion cracking of the aft trunnion of the outer cylinder. This action is intended to address the identified unsafe condition.

DATES:

Effective March 1, 2002.

The incorporation by reference of Boeing Service Bulletin 767-32A0148, Revision 2, dated November 30, 2000, as listed in the regulations, is approved by the Director of the Federal Register as of March 1, 2002.

The incorporation by reference of a certain publication, as listed in the regulations, was approved previously by the Director of the Federal Register as of February 16, 1996 (61 FR 3552, February 1, 1996).

The incorporation by reference of a certain other publication, as listed in the regulations, was approved previously by the Director of the Federal Register as of November 29, 1996 (61 FR 55080, October 24, 1996).

ADDRESSES:

The service information referenced in this AD may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. This information may be examined at the Federal Aviation Administration (FAA), Transport Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT:

John Craycraft, 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:

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 96-21-06, amendment 39-9783 (61 FR 55080, October 24, 1996), which is applicable to certain Boeing Model 767 series airplanes, was published in the Federal Register on August 24, 2001 (66 FR 44553). The action proposed to continue to require inspections and various follow-on actions to detect cracking and corrosion of the aft trunnion of the outer cylinder of the main landing gear (MLG). The action also proposed to continue to require termination of the inspections by repairing the outer cylinder and installing new aft trunnion bushings. Finally, the action proposed to prohibit the use of a particular corrosion inhibiting compound during accomplishment of the terminating action.

Comments

Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received.

Request To Supersede Multiple ADs

One commenter requests that the FAA revise the proposed AD to supersede AD 96-21-06, AD 95-19-10, amendment 39-9372 (60 FR 47689, September 14, 1995), and AD 95-20-51, amendment 39-9398 (60 FR 53109, October 12, 1995), with one AD. The commenter sees no benefit in having four ADs (i.e., the three listed previously and the proposed AD) that address the same area of the aft trunnion of the MLG on Model 767 series airplanes. The commenter states that superseding all of the ADs related to the aft trunnion would ease the administrative burden and simplify the recordkeeping associated with these ADs.

The FAA does not concur with the commenter's request. We note that this AD does supersede AD 96-21-06, one of the ADs to which the commenter refers. We also note that the applicability statements of all three ADs differ; that is, all three ADs apply to different groups of airplanes. With this in mind, combining the three ADs into one superseding AD would result in a lengthy, highly complex AD, which may be confusing for operators. For this reason, we find that a combined AD would be likely to impose more of an administrative and recordkeeping burden, rather than less of one, as the commenter suggests, and could increase the potential for recordkeeping mistakes. For these reasons, we find it inappropriate to supersede the three ADs listed above with a single AD action. No change to the final rule is needed in this regard.

Refer to Alternative Terminating Action

The same commenter presents an alternative if we do not agree to supersede the three ADs identified previously. It asks that we revise paragraph (e) of the proposed AD to refer to Part 4 of Boeing Service Bulletin 767-32A0192, dated May 31, 2001, as an acceptable terminating action for paragraph (e) of the proposed AD. The commenter states that the actions in Part 4 of that service bulletin are equivalent to those in Boeing Service Bulletin 767-32A0148, Revision 2, dated November 30, 2000, which is identified in paragraph (e) of the proposed AD as the appropriate source of service information for the actions in that paragraph.

We concur with the intent of the commenter's request. We agree that accomplishment of “Part 4—Terminating Action” of the Accomplishment Instructions of Boeing Alert Service Bulletin 767-32A0192 terminates paragraph (e) of this AD. We note that we have previously issued another notice of proposed rulemaking (NPRM), Rules Docket Number 2001-NM-189-AD, which, if adopted, would apply to all Boeing Model 767-200, -300, and -300F series airplanes. Paragraph (i) of that NPRM specifies accomplishment of the terminating action in Boeing Alert Service Bulletin 767-32A0192. In addition, paragraph (j) of that NPRM states, “Accomplishment of the actions specified in paragraph (i) of this AD is considered acceptable for compliance with the requirements of paragraph (e) of AD 96-21-06, amendment 39-9783.” The provision of paragraph (j) of that NPRM applies to paragraph (e) of this AD because this AD supersedes AD 96-21-06. Therefore, for clarification, we have added a new paragraph (h) to this AD to state that accomplishment of “Part 4—Terminating Action” of the Accomplishment Instructions of Boeing Alert Service Bulletin 767-32A0192 constitutes terminating action for paragraph (e) of this AD. Paragraphs subsequent to this new paragraph (h) have been reordered accordingly.

Limit Area of Prohibition

One commenter recommends that the proposed AD prohibit the application of the corrosion inhibiting compound Desoto 823E508 (Titanine JC5A) only on the aft trunnion of the MLG. The commenter notes that the wording of paragraph (h) of the proposed rule prohibits application of that compound anywhere on an airplane. The commenter states that service history and laboratory test data have shown that typical usage of this corrosion inhibiting compound in thin layers (such as on fasteners and faying surfaces) does not promote corrosion.

While we neither accept nor reject the commenter's argument, we agree that the unsafe condition associated with this AD relates specifically to the aft trunnion of the MLG. Therefore, it is appropriate to limit the prohibition of the application of the subject corrosion inhibiting compound to the aft trunnion of the MLG. Due to the addition of a paragraph described previously, paragraph (h) of the proposed AD has been reordered as paragraph (i) in this final rule, and we have revised that paragraph accordingly.

Conclusion

After careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule with the changes previously described. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.

Cost Impact

There are approximately 605 Model 767 series airplanes of the affected design in the worldwide fleet. The FAA estimates that 200 airplanes of U.S. registry will be affected by this AD.

The actions that are currently required by AD 96-21-06 take approximately 252 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts cost approximately $9,510 per airplane. Based on these figures, the cost impact of the currently required actions on U.S. operators is estimated to be $4,926,000, or $24,630 per airplane.

The prohibition of a certain corrosion inhibiting compound, which is the only new requirement of this AD, will not change the cost impact on U.S. operators from that associated with AD 96-21-06.

The cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions.

Regulatory Impact

The regulations adopted herein 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. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this action (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. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

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

Adoption of the Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (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. Section 39.13 is amended by removing amendment 39-9783 ( 61 FR 55080, October 24, 1996), and by adding a new airworthiness directive (AD), amendment 39-12607, to read as follows:

2002-01-13 Boeing: Amendment 39-12607. Docket 2001-NM-198-AD. Supersedes AD 96-21-06, Amendment 39-9783.

Applicability: Model 767 series airplanes having line numbers 001 through 605 inclusive, on which the terminating action required by paragraph (e) of this AD has not been accomplished; certificated in any category.

Note 1:

This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (j)(1) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To prevent collapse of the main landing gear (MLG) due to stress corrosion cracking of the aft trunnion of the outer cylinder, accomplish the following:

Note 2:

This AD is merely a restatement of the requirements of AD 96-21-06, amendment 39-9783, with one exception: Only Revision 2, dated November 30, 2000, of Boeing Service Bulletin 767-32A0148, which disallows the use of Desoto 823E508 (Titanine JC5A) corrosion inhibiting compound, may be used after the effective date of this new AD. As allowed by the phrase, “unless accomplished previously,” if those requirements of AD 96-21-06 have already been accomplished prior to the effective date of this AD in accordance with prior versions of that service bulletin, this AD does not require that those actions be repeated. However, the FAA is considering the issuance of a separate rulemaking action to further address the identified unsafe condition on airplanes on which Desoto 823E508 (Titanine JC5A) was used.

Restatement of the Requirements of AD 96-21-06

Inspections and Various Follow-On Actions

(a) Perform the inspections described in paragraph III, Accomplishment Instructions, of Boeing Alert Service Bulletin 767-32A0151, dated November 30, 1995, or Revision 1, dated October 10, 1996, to detect cracking and corrosion of the aft trunnion of the outer cylinder of the MLG at the time specified in paragraph (a)(1), (a)(2), or (a)(3) of this AD, as applicable. These inspections are to be accomplished in accordance with Figure 1 of the service bulletin. Repeat these inspections thereafter at the intervals specified in that service bulletin. To determine the category in which an airplane falls, the age of the outer cylinder of the MLG is to be calculated as of February 16, 1996 (the effective date of AD 96-03-02 R1, amendment 39-9526). For airplanes on which the age of the right MLG differs from the age of the left MLG, an operator may place the airplane into a category that is the higher (numerically) of the two categories to ease its administrative burden, and to simplify the recordkeeping requirements imposed by this AD. Once the category into which an airplane falls is determined, operators must obtain approval from the Manager, Seattle Aircraft Certification Office (ACO), FAA, to move that airplane into another category.

Note 3:

The broken (dash) lines used in Figure 1 of Boeing Alert Service Bulletin 767-32A0151, dated November 30, 1995, and Revision 1, dated October 10, 1996, denote “go to” actions for findings of discrepancies detected during any of the inspections required by this AD.

Note 4:

Boeing Alert Service Bulletin 767-32A0151, dated November 30, 1995, and Revision 1, dated October 10, 1996, refer to Boeing Alert Service Bulletin 767-32A0148, dated December 21, 1995, and Revision 1, dated October 10, 1996, for procedures to repair the outer cylinder and replace the bushings in the outer cylinder of the MLG with new bushings.

(1) For airplanes identified as Category 3 in paragraph I.C. of Boeing Alert Service Bulletin 767-32A0151, dated November 30, 1995, or Revision 1, dated October 10, 1996: Perform the initial inspections within 30 days after February 16, 1996 (the effective date of AD 96-03-02 R1, amendment 39-9526).

(2) For airplanes identified as Category 2 in paragraph I.C. of Boeing Alert Service Bulletin 767-32A0151, dated November 30, 1995, or Revision 1, dated October 10, 1996: Perform the initial inspections within 90 days after February 16, 1996.

(3) For airplanes identified as Category 1 in paragraph I.C. of Boeing Alert Service Bulletin 767-32A0151, dated November 30, 1995, or Revision 1, dated October 10, 1996: Perform the initial inspections prior to the accumulation of 21/2 years since the MLG outer cylinder was new or last overhauled, or within 150 days after February 16, 1996, whichever occurs later.

(b) If no cracking or corrosion is detected during the inspections required by paragraph (a) of this AD, accomplish the follow-on actions described in Boeing Alert Service Bulletin 767-32A0151, November 30, 1995, or Revision 1, dated October 10, 1996, at the time specified in the service bulletin. These follow-on actions are to be accomplished in accordance with that service bulletin.

(c) If any cracking is detected during the inspections required by paragraph (a) of this AD, prior to further flight, replace the outer cylinder with a new or serviceable outer cylinder in accordance with Boeing Alert Service Bulletin 767-32A0151, dated November 30, 1995, or Revision 1, dated October 10, 1996.

(d) If any corrosion is detected during the inspections required by paragraph (a) of this AD, accomplish the follow-on actions at the time specified in the “Corrosion Flowchart,” in Figure 1 of Boeing Alert Service Bulletin 767-32A0151, dated November 30, 1995, or Revision 1, dated October 10, 1996. The follow-on actions are to be accomplished in accordance with that service bulletin.

Terminating Action

(e) Unless previously accomplished in accordance with paragraph (e) of AD 96-21-06, at the time specified in either paragraph (e)(1) or (e)(2) of this AD, as applicable, repair the outer cylinder and replace the bushings in the aft trunnion and crossbolt of the MLG with new bushings, in accordance with Boeing Service Bulletin 767-32A0148, Revision 2, dated November 30, 2000. Accomplishment of this repair and replacement constitutes terminating action for this AD, and for the requirements of AD 95-19-10, amendment 39-9372; and AD 95-20-51, amendment 39-9398.

Note 5:

Boeing Service Bulletin 767-32A0148, Revision 2, dated November 30, 2000, refers to Boeing Component Maintenance Manual (CMM) 32-11-40 for certain procedures.

(1) For airplanes identified as Category 3 in paragraph I.C. of Boeing Alert Service Bulletin 767-32A0151, dated November 30, 1995, or Revision 1, dated October 10, 1996: Accomplish the repair and replacement within 18 months after November 29, 1996 (the effective date of AD 96-21-06, amendment 39-9783).

(2) For airplanes identified as either Category 1 or Category 2 in paragraph I.C. of Boeing Alert Service Bulletin 767-32A0151, dated November 30, 1995, or Revision 1, dated October 10, 1996: Accomplish the repair and replacement at the time specified in either paragraph (e)(2)(i) or (e)(2)(ii) of this AD:

(i) Prior to the accumulation of 51/2 years since the MLG outer cylinders were new or last overhauled, or within 18 months after November 29, 1996, whichever occurs later; or

(ii) Prior to the accumulation of 7 years since the MLG outer cylinders were new or last overhauled, provided that accomplishment of visual and non-destructive testing (NDT) inspections at the times specified in Figure 1 of the Accomplishment Instructions of Boeing Alert Service Bulletin 767-32A0151, dated November 30, 1995, or Revision 1, dated October 10, 1996, are repeated until the repair and replacement are accomplished.

(f) Accomplishment of the inspection requirements of this AD (in accordance with Boeing Alert Service Bulletin 767-32A0151, dated November 30, 1995, or Revision 1, dated October 10, 1996) is considered acceptable for compliance with AD 95-19-10, amendment 39-9372; and AD 95-20-51, amendment 39-9398.

New Requirements of This AD

(g) Except as provided by paragraph (h) of this AD: As of the effective date of this AD, only Revision 2, dated November 30, 2000, of Boeing Service Bulletin 767-32A0148 shall be used to accomplish the actions required by paragraph (e) of this AD.

(h) Accomplishment of the terminating action (including removal of the existing bushings, repair of the aft trunnion area of the outer cylinder, and machining and installation of new bushings) in accordance with “Part 4—Terminating Action” of the Accomplishment Instructions of Boeing Alert Service Bulletin 767-32A0192, dated May 31, 2001, constitutes terminating action for the requirements of paragraph (e) of this AD.

Use of Titanine JC5A Prohibited

(i) As of the effective date of this AD, no person shall use the corrosion inhibiting compound Desoto 823E508 (Titanine JC5A) on the aft trunnion of the MLG on any airplane.

Alternative Methods of Compliance

(j)(1) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Seattle ACO. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Seattle ACO.

Note 6:

Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO.

(2) Alternative methods of compliance, approved in accordance with AD 96-03-02, amendment 39-9497; AD 96-03-02 R1, amendment 39-9526; AD 95-19-10, amendment 39-9372; or AD 95-20-51, amendment 39-9398; are approved as alternative methods of compliance with this AD except as required in paragraph (i) of this AD.

Special Flight Permits

(k) Special flight permits may be issued in accordance with §§ 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

Incorporation by Reference

(l) Except as provided by paragraphs (a) and (h) of this AD, the actions shall be done in accordance with Boeing Alert Service Bulletin 767-32A0151, dated November 30, 1995; Boeing Service Bulletin 767-32A0151, Revision 1, dated October 10, 1996; or Boeing Service Bulletin 767-32A0148, Revision 2, dated November 30, 2000; as applicable.

(1) The incorporation by reference of Boeing Service Bulletin 767-32A0148, Revision 2, dated November 30, 2000, is approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51.

(2) The incorporation by reference of Boeing Alert Service Bulletin 767-32A0151, dated November 30, 1995; was approved previously by the Director of the Federal Register as of February 16, 1996 (61 FR 3552, February 1, 1996).

(3) The incorporation by reference of Boeing Service Bulletin 767-32A0151, Revision 1, dated October 10, 1996; was approved previously by the Director of the Federal Register as of November 29, 1996 (61 FR 55080, October 24, 1996).

(4) Copies may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

Effective Date

(m) This amendment becomes effective on March 1, 2002.

Issued in Renton, Washington, on January 15, 2002.

Vi L. Lipski,

Manager, Transport Airplane Directorate, Aircraft Certification Service.