Airworthiness Directives; Boeing Model 767 Series Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule; request for comments.

SUMMARY:

This document publishes in the Federal Register an amendment adopting airworthiness directive (AD) 2000-10-51 that was sent previously to all known U.S. owners and operators of certain Boeing Model 767 series airplanes by individual notices. This AD requires a one-time inspection to determine whether certain bolts are installed in the side load underwing fittings on both struts, and various follow-on actions, if necessary. This action is prompted by a report that two fractured bolts and one cracked bolt were found in the side load underwing fittings. The actions specified by this AD are intended to detect and correct cracking or fracturing of the tension bolts on the side load underwing fittings on the strut, which would eventually result in loss of the strut.

DATES:

Effective June 19, 2000, to all persons except those persons to whom it was made immediately effective by emergency AD 2000-10-51, issued May 18, 2000, which contained the requirements of this amendment.

The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of June 19, 2000.

Comments for inclusion in the Rules Docket must be received on or before August 14, 2000.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2000-NM-138-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

The applicable service information 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; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT:

James Rehrl, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2783; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION:

On May 18, 2000, the FAA issued emergency AD 2000-10-51, which is applicable to certain Boeing Model 767 series airplanes.

On May 15, 2000, the FAA received a report indicating that an operator found two fractured bolts and one cracked bolt in the side load underwing fittings of a Model 767-200 series airplane. On the affected airplane, both tension bolts on the outboard side load underwing fitting were completely fractured, and one bolt on the inboard side load underwing fitting was cracked. The affected airplane had accumulated 65,759 total flight hours and 17,021 total flight cycles. The cracking and fracturing of the tension bolts is due to stress corrosion. The tension bolts are made of H-11 steel material, which service history has shown to be susceptible to stress corrosion. Fracture of the tension bolts in the side load underwing fittings, if not corrected, would eventually result in loss of the strut.

Explanation of Relevant Service Information

The FAA has reviewed and approved Boeing Alert Service Bulletin 767-57A0074, dated May 17, 2000, and Revision 1, dated May 18, 2000, which describes procedures for a one-time inspection to determine whether H-11 steel tension bolts are installed in the side load underwing fittings on both struts. If any H-11 bolts are found, or if the type of bolt cannot be determined, the alert service bulletin also describes procedures for repetitive ultrasonic inspections to detect cracking or fracturing of the tension bolts in the side load underwing fittings on both struts, and corrective action, if necessary. Corrective action involves replacement of both tension bolts in the affected side load underwing fitting with new, improved bolts. The new, improved bolts are made of Inconel, which is more resistant to stress corrosion cracking than H-11 steel. Replacement of all H-11 steel tension bolts in the side load underwing fittings with new, improved bolts, as described in the alert service bulletin, eliminates the need for the repetitive inspections.

Explanation of Applicability

This AD applies to Model 767 series airplanes having line numbers 1 through 230 inclusive. The airplane manufacturer's records show that airplanes having line numbers 1 through 162 inclusive are likely to have H-11 steel tension bolts installed in the side load underwing fittings on the struts. However, the FAA has determined that it is possible that airplanes with line numbers 163 through 230 inclusive also have H-11 steel bolts installed. Therefore, this AD requires a one-time inspection on all Model 767 series airplanes with line numbers 1 through 230 inclusive to determine whether H-11 steel tension bolts are installed. For airplanes having line numbers 1 through 162 inclusive, this AD requires the initial inspection within 5 days. For airplanes having line numbers 163 through 230 inclusive, this AD requires the initial inspection within 10 days. Also, for airplanes having line numbers 163 through 230 inclusive on which H-11 steel bolts are found to be installed, this AD requires that operators report this fact to the FAA.

Explanation of Requirements of the Rule

Since the unsafe condition described is likely to exist or develop on other airplanes of the same type design, the FAA issued emergency AD 2000-10-51 to require a one-time inspection to determine whether H-11 steel tension bolts are installed in the side load underwing fittings on both struts. If an H-11 steel tension bolt is installed, or if the type of bolt cannot be determined, this AD requires repetitive ultrasonic inspections to detect cracking or fracturing of the tension bolts in the side load underwing fittings on both struts, and corrective action, if necessary. For certain airplanes, this AD also requires additional inspections to detect discrepancies of adjacent structure. For certain other airplanes, as described previously, this AD requires that operators report results of inspection findings to the FAA. This AD also provides an optional terminating action for the repetitive inspections described previously. The actions are required to be accomplished in accordance with the alert service bulletin described previously, except as discussed below.

Difference Between Alert Service Bulletin and This AD

Operators should note that the alert service bulletin recommends that the one-time inspection to determine whether H-11 steel tension bolts are installed be performed within 5 days after receipt of the alert service bulletin. However, as described previously, this AD requires that the inspection be accomplished within 5 days after the effective date of this AD only on airplanes having line numbers 1 through 162 inclusive. On airplanes having line numbers 163 through 230 inclusive, this AD requires that this inspection be accomplished within 10 days.

Operators also should note that the alert service bulletin specifies that, if both tension bolts on one fitting are found cracked or fractured, the manufacturer must be contacted for additional inspection requirements to detect discrepancies of adjacent structure. This AD requires such additional inspection requirements to be accomplished in accordance with a method approved by the FAA.

Interim Action

This is considered to be interim action. The FAA is currently considering requiring the replacement of all H-11 steel tension bolts in the side load underwing fittings with new, improved bolts, which would constitute terminating action for the repetitive inspections required by this AD. However, the planned compliance time for the replacement would be sufficiently long so that notice and opportunity for prior public comment would be practicable.

Determination of Rule's Effective Date

Since it was found that immediate corrective action was required, notice and opportunity for prior public comment thereon were impracticable and contrary to the public interest, and good cause existed to make the AD effective immediately by individual notices issued on May 18, 2000, to all known U.S. owners and operators of Boeing Model 767 series airplanes having line numbers 1 through 230 inclusive. These conditions still exist, and the AD is hereby published in the Federal Register as an amendment to section 39.13 of the Federal Aviation Regulations (14 CFR 39.13) to make it effective to all persons.

Comments Invited

Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the 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 that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2000-NM-138-AD.” The postcard will be date stamped and returned to the commenter.

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.

The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and that it is not a “significant regulatory action” under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket.

A copy of it, if filed, 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.

2. Section 39.13 is amended by adding the following new airworthiness directive:

2000-10-51 Boeing: Amendment 39-11770. Docket 2000-NM-138-AD.

Applicability: Model 767 series airplanes, line numbers (L/N) 1 through 230 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 (g) 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 detect and correct cracking or fracturing of the tension bolts on the side load underwing fittings on the strut, which would eventually result in loss of the strut, accomplish the following:

One-Time Inspection

(a) At the applicable time specified in paragraph (a)(1) or (a)(2) of this AD, perform a one-time inspection of the tension bolts in the side load underwing fittings on both struts to determine whether tension bolts made of H-11 steel are installed, in accordance with Boeing Alert Service Bulletin 767-57A0074, dated May 17, 2000, or Revision 1, dated May 18, 2000. If the inspection shows conclusively that no H-11 steel bolt is installed, no further action is required by this AD.

(1) For airplanes having L/N 1 through 162 inclusive: Inspect within 5 days after the effective date of this AD.

(2) For airplanes having L/N 163 through 230 inclusive: Inspect within 10 days after the effective date of this AD.

Repetitive Inspections

(b) If any H-11 steel bolt is found during the inspection required by paragraph (a) of this AD, or if the type of bolt cannot be determined: Prior to further flight, perform an ultrasonic inspection to detect cracking or fracturing of the tension bolts in the side load underwing fittings on both struts, in accordance with Boeing Alert Service Bulletin 767-57A0074, dated May 17, 2000, or Revision 1, dated May 18, 2000. Repeat the inspection thereafter at intervals not to exceed 500 flight hours or 300 flight cycles, whichever occurs later.

Replacement

(c) If any cracked or fractured bolt is found during any inspection required by paragraph (b) of this AD, prior to further flight, replace both tension bolts in the affected side load underwing fitting with new, improved bolts, in accordance with Boeing Alert Service Bulletin 767-57A0074, dated May 17, 2000, or Revision 1, dated May 18, 2000.

Additional Inspection Requirements

(d) If both tension bolts in one side load underwing fitting are found cracked or fractured during any inspection required by paragraph (b) of this AD, prior to further flight, perform inspections to detect discrepancies of adjacent structure in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. For an inspection method to be approved by the Manager, Seattle ACO, as required by this paragraph, the Manager's approval letter must specifically reference this AD.

Reporting Requirement

(e) For airplanes having L/N 163 through 230 inclusive on which an H-11 bolt is found installed, or on which the type of bolt cannot be determined during the inspection required by paragraph (a) of this AD: Within 48 hours after performing the inspection required by paragraph (b) of this AD, submit a report of findings to the Manager, Seattle ACO, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; fax (425) 227-1181. The report must include the type of bolt found and the airplane serial number. Information collection requirements contained in this regulation have been approved by the Office of Management and Budget (OMB) under the provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.), and have been assigned OMB Control Number 2120-0056.

Optional Terminating Action

(f) Replacement of all H-11 steel tension bolts in the side load underwing fittings on both struts with new, improved bolts, in accordance with Boeing Alert Service Bulletin 767-57A0074, dated May 17, 2000, or Revision 1, dated May 18, 2000, constitutes terminating action for this AD.

Alternative Methods of Compliance

(g) 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 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

(h) 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

(i) Except as provided by paragraph (d) of this AD, the actions shall be done in accordance with Boeing Alert Service Bulletin 767-57A0074, dated May 17, 2000, or Boeing Alert Service Bulletin 767-57A0074, Revision 1, dated May 18, 2000. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. 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

(j) This amendment becomes effective on June 19, 2000, to all persons except those persons to whom it was made immediately effective by emergency AD 2000-10-51, issued on May 18, 2000, which contained the requirements of this amendment.