03-48. Airworthiness Directives; Boeing Model 767 Series Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the supersedure of an existing airworthiness directive (AD), applicable to certain Boeing Model 767 series airplanes, that currently requires repetitive detailed inspections to detect cracked, corroded, or stained collar fittings on both inboard trailing edge flaps; and follow-on corrective actions, if necessary. This action would expand the applicability in the existing AD, and would add repetitive inspections for discrepancies of the collar fittings, torque tube, and splined bushings on both inboard trailing edge flaps; and follow-on and corrective actions, if necessary. The actions specified by the proposed AD are intended to prevent failure of the collar fittings, which could result in separation of the inboard trailing edge flap and consequent reduced controllability of the airplane. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by February 18, 2003.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-395-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to [phone]. Comments may also be sent via the Internet using the following address: [e-mail]. Comments sent via fax or the Internet must contain “Docket No. 2001-NM-395-AD” in the subject line and need not be submitted in triplicate. Comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 for Windows or ASCII text.

The service information referenced in the proposed rule may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT:

Suzanne Masterson, 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

Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this action may be changed in light of the comments received.

Submit comments using the following format:

• Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues.
• For each issue, state what specific change to the proposed AD is being requested.
• Include justification (e.g., reasons or data) for each request.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2001-NM-395-AD.” The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-395-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

On October 21, 1998, the FAA issued AD 98-22-12, amendment 39-10859 (63 FR 57577, October 28, 1998), applicable to certain Boeing Model 767 series airplanes, to require repetitive detailed inspections to detect cracked, corroded, or stained collar fittings on both inboard trailing edge flaps; and follow-on corrective actions, if necessary. That action was prompted by a report indicating that a collar fitting suffered a complete fracture as a result of stress corrosion cracking. The requirements of that AD are intended to prevent separation of the inboard trailing edge flap from the airplane due to fractured collar fittings.

In the preamble to AD 98-22-12, the FAA indicated that the actions required by that AD were considered “interim action” and that further rulemaking action was being considered. We now have determined that further rulemaking action is indeed necessary, and this proposed AD follows from that determination.

Actions Since Issuance of Previous Rule

Since the issuance of AD 98-22-12, the airplane manufacturer has received reports indicating corrosion of the splined components of the inboard support of the trailing edge flap. The root cause of the corrosion was determined to be a breakdown of the MIL-G-23827 grease in the joint, which subsequently allowed moisture to enter the joint. Eventually, the splined components corroded and, in two instances, stress corrosion cracking of one component occurred. We now have determined that it is necessary to require additional inspections on airplanes affected by the existing AD and to expand the applicability of the existing AD to include airplanes that were assembled with the corrosion inhibiting compound (CIC) BMS 3-27 and delivered before the Maintenance Planning Document (MPD) was revised by the manufacturer in April 1999. The MPD was revised to include the 12-year/24,000-flight-cycle teardown inspection as part of normal airplane maintenance for airplanes assembled with BMS 3-27.

Explanation of Relevant Service Information

We have reviewed and approved Boeing Alert Service Bulletin 767-57A0066, Revision 3, including Appendices A and B, dated December 19, 2001, and Evaluation Form. (The existing AD shows Boeing Alert Service Bulletin 767-57A0066, Revision 1, dated August 6, 1998, as the appropriate source of service information for accomplishment of the actions required by that AD.) Revision 3 of the service bulletin adds Part 5—Titanine Inspection and Rework, which describes procedures for doing Part 1-Inspection, Part 3-Spline Inspection, and Part 4-Spline Rework; then repeating the spline inspection at the intervals specified if it is determined that the CIC Titanine JC5A was used per Revision 2 of the service bulletin, dated February 18, 1999, or if the maintenance records are inconclusive on the type of CIC used. Subsequent to issuance of Revision 2 of the service bulletin, it was determined that Titanine JC5A does not provide adequate corrosion protection for the joints specified in the service bulletin. Revision 3 of the service bulletin also describes procedures for light wear rework of the splines if no corrosion or corrosion pits are found, in lieu of a complete spline evaluation and overhaul. Appendix A, titled “Guide for Determining the Level of Rework Required,” was added to assist operators in determining if the light wear rework procedure can be used. Part 3—Spline Inspection describes procedures for repetitive spline inspections in lieu of terminating action as routine scheduled maintenance, and defines procedural clarifications and changes. Accomplishment of the actions specified in the service bulletin is intended to adequately address the identified unsafe condition.

Explanation of Requirements of Proposed Rule

Since an unsafe condition has been identified that is likely to exist or develop on other products of this same type design, the proposed AD would supersede AD 98-22-12 to continue to require repetitive detailed inspections to detect cracked, corroded, or stained collar fittings on both inboard trailing edge flaps; and follow-on corrective actions, if necessary. This new action would expand the applicability in the existing AD, and would add repetitive inspections for discrepancies of the collar fittings, torque tube, and splined bushings on both inboard trailing edge flaps; and follow-on and corrective actions, if necessary. The actions would be required to be accomplished in accordance with the service bulletin described previously, except as discussed below.

Difference Between Service Information and This Proposed AD

Operators should note that the number of airplanes to which this proposed AD is applicable is larger than that published in the service bulletin. Additional line numbers of airplanes have been included (line numbers 1 through 749 inclusive), as advised in Boeing Letter B-H210-01-0432, dated December 14, 2001.

Explanation of Changes Made to Existing Requirements

We have changed all references to a “detailed visual inspection” in the existing AD to a “detailed inspection” in this AD. We also have added Part 4-Spline Rework, specified in Revision 3 of the service bulletin, to paragraphs (a)(3) and (a)(4)(ii) of the existing AD for the repair of corrosion, as an alternative to repairing per the Manager, Seattle Aircraft Certification Office.

Cost Impact

There are approximately 738 airplanes of the affected design in the worldwide fleet. The FAA estimates that 306 airplanes of U.S. registry would be affected by this proposed AD.

The actions that are currently required by AD 98-22-12 take approximately 2 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the currently required actions is estimated to be $120 per airplane, per inspection cycle.

The new inspections and refinishing that are proposed in this AD action would take approximately 2 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the proposed requirements of this AD on U.S. operators is estimated to be $36,720, or $120 per airplane, per cycle.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the proposed 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.

Should an operator be required to do the replacement proposed in this AD action, it would take approximately 63 work hours per wing, at an average labor rate of $60 per work hour. Parts costs are not available at this time. Based on these figures, the cost impact of the replacement is estimated to be $3,780 per wing, per airplane.

Should an operator be required to do the rework proposed in this AD action, it would take approximately 63 work hours per wing, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the rework is estimated to be $3,780 per wing, per airplane.

Regulatory Impact

The regulations proposed herein 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. Therefore, it is determined that this proposal would not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that 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); and (3) if promulgated, 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 copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 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 39-10859 (63 FR 57577, October 28, 1998), and by adding a new airworthiness directive (AD), to read as follows:

Boeing: Docket 2001-NM-395-AD. Supersedes AD 98-22-12, Amendment 39-10859.

Applicability: Model 767 series airplanes, line numbers 1 through 749 inclusive, 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 failure of the collar fittings on the inboard trailing edge flaps, which could result in separation of the flap and consequent reduced controllability of the airplane, accomplish the following:

Restatement of Requirements of AD 98-22-12

Detailed Inspections/Corrective Actions

(a) For airplanes having line numbers 1 through 721 inclusive, except as provided by paragraphs (c) and (e) of this AD: Within 8 years since the date of manufacture of the airplane, or within 90 days after November 12, 1998 (the effective date of AD 98-22-12, amendment 39-10859), whichever occurs later; perform a detailed inspection of the collar fittings of both inboard trailing edge flaps to detect cracks, corrosion, or staining, in accordance with Part 1 of the Accomplishment Instructions of Boeing Alert Service Bulletin 767-57A0066, Revision 1, dated August 6, 1998; or Revision 3, dated December 19, 2001; including Appendices A and B, and excluding Evaluation Form. As of the effective date of this AD, only Revision 3 shall be used.

Note 2:

For the purposes of this AD, a detailed inspection is defined as: “An intensive visual examination of a specific structural area, system, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at intensity deemed appropriate by the inspector. Inspection aids such as mirror, magnifying lenses, etc., may be used. Surface cleaning and elaborate access procedures may be required.”

(1) If no cracked, corroded, or stained collar fitting is found, repeat the detailed inspection required by paragraph (a) of this AD thereafter at intervals not to exceed 120 days.

(2) If any cracked collar fitting is found, prior to further flight, install a new collar fitting in accordance with Part 2 of the Accomplishment Instructions of the alert service bulletin.

(3) If any corroded collar fitting is found, prior to further flight, repair the corrosion in accordance with Part 4 of the Accomplishment Instructions of Revision 3 of the service bulletin; or in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA.

(4) If any stained collar fitting is found, accomplish the requirements of paragraphs (a)(4)(i) and (a)(4)(ii) of this AD at the compliance times specified.

(i) Repeat the detailed inspection required by paragraph (a) of this AD thereafter at intervals not to exceed 45 days; and

(ii) Within 18 months after finding the stained collar fitting, accomplish Part 2 of the Accomplishment Instructions of the alert service bulletin. If any corroded collar fitting is found, before further flight, repair the corrosion in accordance with Part 4 of the Accomplishment Instructions of Revision 3 of the service bulletin; or in accordance with a method approved by the Manager, Seattle ACO.

New Requirements of This AD

Detailed Inspection

(b) For airplane line number 723: Within 8 years since the date of manufacture of the airplane, or within 90 days after the effective date of this AD, whichever is later; do a detailed inspection of the collar fittings of both inboard trailing edge flaps to detect cracks, corrosion, or staining, as specified in paragraph (a) of this AD, in accordance with Part 1 of the Accomplishment Instructions of Boeing Alert Service Bulletin 767-57A0066, Revision 3, dated December 19, 2001; including Appendices A and B, and excluding Evaluation Form. Then do the applicable actions specified in paragraphs (a)(1), (a)(2), (a)(3), and (a)(4) of this AD.

Repetitive Inspections/Follow-On and Corrective Actions

(c) For airplanes having line numbers 1 through 703 inclusive, 705 through 715 inclusive, 717, 718, 721, and 723; and for the right-hand side of the airplane on line number 716: Within 10 years since the date of manufacture of the airplane, or within 4 years after the effective date of this AD, whichever is later; do a detailed (spline) inspection of the collar fittings, torque tube, and splined bushings for discrepancies (including cracks, fractures, corrosion, corrosion pits, and light wear), in accordance with Part 3 of the Accomplishment Instructions of Boeing Alert Service Bulletin 767-57A0066, Revision 3, dated December 19, 2001; including Appendices A and B, and excluding Evaluation Form. Accomplishment of the inspections required by this paragraph, before the initial inspection required by paragraph (a) of this AD, meets the inspection requirements in paragraph (a) of this AD.

(d) If no discrepancy is found during any inspection required by paragraph (c) or (g) of this AD, before further flight, refinish the parts in accordance with Boeing Alert Service Bulletin 767-57A0066, Revision 3, dated December 19, 2001; including Appendices A and B, and excluding Evaluation Form; and repeat the inspection every 24,000 flight cycles or 12 years, whichever is first. Accomplishment of this paragraph terminates the repetitive inspections required by paragraph (a) of this AD.

(e) If any discrepancy is found during any inspection required by paragraph (c) or (g) of this AD, before further flight, do the actions specified in either paragraph (e)(1) or (e)(2) of this AD in accordance with Boeing Alert Service Bulletin 767-57A0066, Revision 3, dated December 19, 2001; including Appendices A and B, and excluding Evaluation Form. Accomplishment of this paragraph terminates the repetitive inspections required by paragraph (a) of this AD.

(1) Replace the affected part with a new part, and reassemble the joint with liberal coatings of corrosion inhibiting compound (CIC) BMS 3-27 or BMS 3-38, in accordance with the Accomplishment Instructions of the service bulletin. Repeat the applicable inspection every 24,000 flight cycles or 12 years, whichever is first.

(2) Rework the affected part, and reassemble the joint with liberal coatings of CIC BMS 3-27 or BMS 3-38, in accordance with the Accomplishment Instructions of the service bulletin. Repeat the applicable inspection as specified in paragraph (e)(2)(i), (e)(2)(ii), or (e)(2)(iii) of this AD, as applicable.

(i) If five or fewer spline lengths are reworked per Figure 8 of the service bulletin, repeat the inspection every 24,000 flight cycles or 12 years, whichever is first.

(ii) If more than five spline lengths, but fewer than or equal to the maximum number of spline lengths allowed per Figure 8 of the service bulletin are reworked, repeat the inspection every 12,000 flight cycles or 6 years, whichever is first.

(iii) If more than the maximum number of spline lengths allowed per Figure 8 of the service bulletin are reworked, before further flight, replace the splined component and repeat the inspection every 24,000 flight cycles or 12 years, whichever is first.

Additional Inspections for Airplanes Inspected per Revision 2 of the Service Bulletin

(f) For any airplane on which the inspection required by paragraph (a) of this AD was done in accordance with Boeing Alert Service Bulletin 767-57A0066, Revision 2, dated February 18, 1999; and on which the CIC Titanine JC5A was used, or the maintenance records are inconclusive of the type of CIC used: Do the initial inspection and follow-on actions specified in paragraph (c) of this AD within 3 years after the most recent inspection done in accordance with Revision 2 of the service bulletin, or within 90 days after the effective date of this AD, whichever is later.

Airplanes Assembled With BMS 3-27

(g) For airplanes having line numbers 704, 719, and 720, 722, and 724 through 749 inclusive; and for the left-hand side of the airplane on line number 716: Within 12 years since the date of manufacture of the airplane, or within 24,000 flight cycles after the effective date of this AD, whichever is first; do a detailed (spline) inspection of the collar fittings, torque tube, and splined bushings for discrepancies (including cracks, fractures, corrosion, corrosion pits, and light wear). Do the inspection in accordance with Part 3 of the Accomplishment Instructions of Boeing Alert Service Bulletin 767-57A0066, Revision 3, dated December 19, 2001; including Appendices A and B, and excluding Evaluation Form, then, before further flight, do the applicable actions specified in either paragraph (d) or (e) of this AD.

(h) If the initial inspection required by paragraph (a) of this AD has not been done as of the effective date of this AD, operators may do the inspection required by paragraph (g) of this AD in lieu of the inspection required by paragraph (a) of this AD, at the time specified.

Use of Titanine JC5A Prohibited

(i) As of the effective date of this AD, no person shall use the CIC Titanine JC5A on the collar fittings, torque tube, and splined bushings 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.

(2) Alternative methods of compliance, approved previously in accordance with AD 98-22-12, Amendment 39-10859, are not considered to be approved as alternative methods of compliance with this AD.

Note 3:

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

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.

Issued in Renton, Washington, on December 27, 2002.

Vi L. Lipski,

Manager, Transport Airplane Directorate, Aircraft Certification Service.