02-24688. 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 all Boeing Model 767 series airplanes, that currently requires an inspection to ensure that all bolts of the support beam of the hinge fitting assembly on both the left- and right-hand outboard trailing edge flaps are the correct length and type, and correction of any discrepancy found. This action would reduce the applicability, add inspections, and mandate terminating action for certain airplanes. The actions specified by the proposed AD are intended to prevent failure of the bolts that attach the outboard trailing edge flap to the support beam, which could result in loss of the flap and consequent reduced controllability of the airplane. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by November 14, 2002.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2002-NM-158-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. 2002-NM-158-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:

Technical Information: 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].

Other Information: Sandi Carli, Airworthiness Directive Technical Editor/Writer; telephone [phone], fax [phone]. Questions or comments may also be sent via the Internet using the following address: [e-mail]. Questions or comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 for Windows or ASCII text.

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 2002-NM-158-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. 2002-NM-158-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

On April 25, 1997, the FAA issued AD 97-08-51, amendment 39-10012 (62 FR 24015, May 2, 1997), applicable to all Boeing Model 767 series airplanes, to require an inspection to ensure that all bolts of the hinge fitting assembly support beam on both the left- and right-hand outboard trailing edge flaps are the correct length and type, and correction of any discrepancy found. That action was prompted by a report indicating that a 20-foot section of the right-hand outboard trailing edge flap separated from the airplane due to failure of four bolts of the most inboard hinge fitting. The requirements of that AD are intended to detect and correct such failed bolts, which could result in loss of an outboard trailing edge flap, and consequent reduced controllability of the airplane.

Actions Since Issuance of Previous Rule

Since the issuance of AD 97-08-51, the manufacturer has done a structural analysis of the titanium bolts of the support beam of the hinge fitting assembly on both the left- and right-hand outboard trailing edge flaps on Boeing Model 767 series airplanes, line numbers 1 through 710 inclusive, which had titanium bolts installed during production. Model 767 series airplanes having line numbers 711 and subsequent had steel bolts installed during production. The analysis revealed that titanium bolts do not meet airplane fatigue life and damage tolerance criteria and must be replaced with steel bolts, which are less susceptible to fatigue and subsequent damage.

Explanation of Relevant Service Information

We have reviewed and approved Boeing Alert Service Bulletin 767-27A0151, Revision 4, dated August 27, 1998. Boeing Alert Service Bulletin 767-27A0151, Revision 1, dated April 2, 1997, was referenced in the existing AD for accomplishment of the specified actions. Revision 4 adds a second inspection for airplanes on which the one-time inspection specified in Revision 1 was accomplished prior to the accumulation of 5,000 total flight cycles or 12,500 total flight hours.

We also have reviewed and approved Boeing Service Bulletin 767-27A0155, Revision 2, dated July 8, 1999, which describes procedures for repetitive inspections (torque checks) of the bolts of the support beam of the hinge fitting assembly on both the left- and right-hand outboard trailing edge flaps, and retorque if necessary. The service bulletin also describes procedures for terminating action, which would eliminate the need for the repetitive inspections. The terminating action includes replacement of the six titanium bolts in each flap support fitting with steel bolts and self-aligning washers, and installation of radius fillers at the four aft bolt locations in each flap support fitting.

Accomplishment of the actions specified in the service bulletins 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 97-08-51 to continue to require an inspection to ensure that all bolts of the support beam of the hinge fitting assembly on both the left- and right-hand outboard trailing edge flaps are the correct length and type, and correction of any discrepancy found. The proposed AD also would reduce the applicability, add inspections, and mandate terminating action for certain airplanes. The actions would be required to be accomplished in accordance with the service bulletins described previously.

Cost Impact

There are approximately 700 airplanes of the affected design in the worldwide fleet. The FAA estimates that 287 airplanes of U.S. registry would be affected by this proposed AD.

The actions that are currently required by AD 97-08-51 take approximately 7 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 $420 per airplane.

The torque check that is 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 torque check proposed by this AD on U.S. operators is estimated to be $34,440, or $120 per airplane, per check.

The terminating action that is proposed in this AD action would take approximately 3 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts would cost approximately $3,058 per airplane. Based on these figures, the cost impact of the terminating action proposed by this AD on U.S. operators is estimated to be $929,306, or $3,238 per airplane.

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

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 39-10012 (62 FR 24015, May 2, 1997), and by adding a new airworthiness directive (AD), to read as follows:

Boeing: Docket 2002-NM-158-AD. Supersedes AD 97-08-51, amendment 39-10012.

Applicability: Model 767 series airplanes, line numbers 1 through 710 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 (i)(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 bolts that attach the outboard trailing edge flap to the support beam, which could result in loss of the flap and consequent reduced controllability of the airplane, accomplish the following:

Inspection

(a) Perform an inspection to check the bolt torque, bolt length, and type of all bolts of both hinge fittings on the left- and right-hand outboard trailing edge flaps, in accordance with Boeing Alert Service Bulletin 767-27A0151, Revision 1, dated April 2, 1997; or Revision 4, dated August 27, 1998. Perform these inspections at the time specified in paragraph (a)(1) or (a)(2) of this AD, as applicable.

(1) For airplanes that accumulated 15,000 or more total flight cycles, or 37,500 or more total flight hours, as of May 7, 1997 (the effective date of AD 97-08-51, amendment 39-10012): Perform the inspection within 15 days after May 7, 1997.

(2) For all other airplanes: Perform the inspection at the later of the times specified in paragraphs (a)(2)(i) and (a)(2)(ii) of this AD.

(i) Prior to the accumulation of 10,000 total flight cycles, or 25,000 total flight hours, whichever occurs first.

(ii) Within 30 days after May 7, 1997.

Repeat Inspection for Certain Airplanes

(b) For airplanes on which the inspection required by paragraph (a) of this AD was accomplished prior to the accumulation of 5,000 total flight cycles or 12,500 total flight hours: Repeat the inspection required by paragraph (a) of this AD one time within 120 days after the effective date of this AD.

Corrective Actions

(c) If any bolt of the hinge fittings of the left- and right-hand outboard trailing edge flaps is below the torque check threshold specified in Boeing Alert Service Bulletin 767-27A0151, Revision 1, dated April 2, 1997; or Revision 4, dated August 27, 1998: Prior to further flight, accomplish the actions specified in paragraph (c)(1) or (c)(2) of this AD, in accordance with the alert service bulletin.

(1) Perform a dye penetrant inspection of all the bolts of the hinge fitting to detect any cracking or discrepancy.

(i) If no cracking or discrepancy is detected, reinstall the bolt using new nuts and washers.

(ii) If any cracking or discrepancy is detected, replace the cracked or discrepant bolt with a new or serviceable bolt.

(2) Replace all of the bolts of both hinge fittings with new or serviceable bolts.

(d) If the length or type of any bolt of the hinge fittings of the left- and right-hand outboard trailing edge flaps is outside the specifications of Boeing Alert Service Bulletin 767-27A0151, Revision 1, dated April 2, 1997; or Revision 4, dated August 27, 1998: Prior to further flight, replace the bolt with a new or serviceable bolt in accordance with the alert service bulletin.

Credit for Actions Accomplished per Previous Revisions of Service Bulletin

(e) Accomplishment of the actions specified in paragraphs (a), (c), and (d) of this AD, in accordance with Boeing Alert Service Bulletin 767-27A0151, dated April 1, 1997; Revision 2, dated April 10, 1997; or Revision 3, dated July 7, 1997; before the effective date of this AD; is considered acceptable for compliance with the applicable requirements of this AD.

Repetitive Inspections

(f) Within 3 years, 12,500 flight hours, or 6,000 flight cycles after accomplishment of paragraph (a) of this AD, whichever is first; or within 90 days after the effective date of this AD, whichever is later: Perform an inspection to check the bolt torque of both hinge fittings on the left- and right-hand outboard trailing edge flaps, and retorque if applicable, in accordance with Boeing Service Bulletin 767-27A0155, Revision 2, dated July 8, 1999. Repeat the inspection every 3 years, 12,500 flight hours, or 6,000 flight cycles, whichever is first.

Terminating Action

(g) Within 6 years, 25,000 flight hours, or 12,000 flight cycles after accomplishment of paragraph (a) of this AD, whichever is first; or within 90 days after the effective date of this AD; whichever is later: Perform the terminating action (including replacement of the six titanium bolts in each flap support fitting with steel bolts and self-aligning washers, and installation of radius filters at the four aft bolt locations), in accordance with Part 2 of the Accomplishment Instructions of Boeing Service Bulletin 767-27A0155, Revision 2, dated July 8, 1999. Accomplishment of this paragraph ends the repetitive inspections required by paragraph (f) of this AD.

Credit for Actions Accomplished per Previous Revisions of Service Bulletin

(h) Accomplishment of the actions specified in paragraphs (f) and/or (g) of this AD, in accordance with Boeing Alert Service Bulletin 767-29A0155, dated August 27, 1998, or Revision 1, dated December 22, 1998, before the effective date of this AD, is considered acceptable for compliance with the applicable requirements of this AD.

Alternative Methods of Compliance

(i)(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 Aircraft Certification Office (ACO), FAA. 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 97-08-51, amendment 39-10012, are approved as alternative methods of compliance with paragraphs (a), (b), and (c) of this AD.

Note 2:

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

(j) Special flight permits may be issued in accordance with sections 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 September 23, 2002.

Ali Bahrami,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.