# AD 96-05-07: Airworthiness Directives; Boeing Model 757 Series Airplanes Equipped with Pratt & Whitney Engines - Type: Airworthiness directive - Effective: April 10, 1996 - Published: March 11, 1996, 61 FR 9599–9601 - Issued as: Final rule - Superseded by: Nothing supersedes this AD - Amendment: 39-9533 - Docket: 94-NM-72-AD - Official PDF: https://openairdocs.org/files/sha256/f8/36/f836fd7122076953ab6dd6853dc1012c3e779f1f902f7a1996974363003cd114 (from https://www.govinfo.gov/content/pkg/FR-1996-03-11/pdf/96-5369.pdf) - Federal Register: https://www.federalregister.gov/documents/1996/03/11/96-5369/airworthiness-directives-boeing-model-757-series-airplanes-equipped-with-pratt-and-whitney-engines - Page: https://openairdocs.org/ad/96-05-07 ## Summary This amendment supersedes an existing airworthiness directive (AD), applicable to certain Boeing Model 757 series airplanes, that currently requires repetitive inspections to detect cracking in the midspar fuse pins and replacement of certain fuse pins. This amendment requires inspection of certain fuse pins, and replacement of certain fuse pins with certain other fuse pins. This amendment also requires inspections of refinished straight fuse pins and replacement of cracked refinished straight fuse pins with certain other straight fuse pins. This amendment is prompted by the development of new corrosion-resistant steel fuse pins. The actions specified by this AD are intended to prevent cracking of the midspar fuse pins, which may lead to separation of the strut and engine from the wing of the airplane. ## The airworthiness directive ### PART 39--AIRWORTHINESS DIRECTIVES 1. The authority citation for part 39 continues to read as follows: Authority: 49 USC 106(g), 40113, 44701. ### Sec. 39.13 [Amended] 2. Section 39.13 is amended by removing amendment 39-8666 (58 FR 45044, August 26, 1993), and by adding a new airworthiness directive (AD), amendment 39-9533, to read as follows: 96-05-07 Boeing: Amendment 39-9533. Docket 94-NM-72-AD. Supersedes AD 93-16-09, Amendment 39-8666. Applicability: Model 757 series airplanes equipped with Pratt & Whitney engines, certificated in any category. Note 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been otherwise 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 (f) 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. Note 2: Inspections accomplished prior to the effective date of this amendment in accordance with the procedures described in Boeing Service Bulletin 757-54A0019, Revision 4, dated May 27, 1993; Revision 3, dated March 26, 1992; or Revision 2, dated October 11, 1989; are considered acceptable for compliance with the applicable inspection specified in this amendment. To prevent cracking of the midspar fuse pins, which may lead to separation of the strut and engine from the wing of the airplane, accomplish the following: ### (a) (a) For airplanes equipped with straight fuse pins, part number (P/N) 311N5067-1: Prior to the accumulation of 3,800 total flight cycles on the straight fuse pin, perform an eddy current inspection to detect cracking in the straight fuse pins, in accordance with Boeing Service Bulletin 757-54A0019, Revision 5, dated March 17, 1994. (1) If no cracking is detected, repeat the inspection thereafter at intervals not to exceed 1,000 flight cycles on the straight fuse pin. (2) If any cracking is detected, prior to further flight, accomplish the requirements of either paragraph (a)(2)(i) or (a)(2)(ii) of this AD. (i) Replace the cracked straight fuse pin with a new straight fuse pin, P/N 311N5067-1. Prior to the accumulation of 3,800 total flight cycles on that newly installed straight fuse pin, perform an eddy current inspection to detect cracking in that straight fuse pin, in accordance with the service bulletin. Repeat the inspection thereafter at intervals not to exceed 1,000 flight cycles on that newly installed straight fuse pin. Or (ii) Replace the cracked straight fuse pin with a new 15-5PH fuse pin, P/N 311N5217-1. Prior to the accumulation of 14,000 total flight cycles on that newly installed 15-5PH fuse pin, perform an eddy current inspection to detect cracking in that newly installed 15-5PH fuse pin, in accordance with the procedures described in the service bulletin. Repeat the inspection thereafter at intervals not to exceed 3,500 flight cycles on that newly installed 15-5PH fuse pin. ### (b) (b) For airplanes equipped with refinished straight fuse pins, P/N 311N5067-1: Prior to the accumulation of 1,000 total flight cycles on the refinished straight fuse pin, perform an eddy current inspection to detect cracking in the refinished straight fuse pins, in accordance with Boeing Service Bulletin 757-54A0019, Revision 5, dated March 17, 1994. (1) If no cracking is detected, repeat the inspection thereafter at intervals not to exceed 1,000 flight cycles on the refinished straight fuse pin. (2) If any cracking is detected, prior to further flight, accomplish the requirements of either paragraph (b)(2)(i), (b)(2)(ii), or (b)(2)(iii) of this AD, in accordance with the service bulletin. (i) Replace the cracked refinished straight fuse pin with a crack-free refinished straight fuse pin, P/N 311N5067-1. Prior to the accumulation of 1,000 total flight cycles on that newly installed refinished straight fuse pin, perform an eddy current inspection to detect cracking in that newly installed refinished straight fuse pin, in accordance with the procedures described in the service bulletin. Repeat this inspection thereafter at intervals not to exceed 1,000 flight cycles on the newly installed refinished straight fuse pin. Or (ii) Replace the cracked refinished straight fuse pin with a new straight fuse pin, P/N 311N5067-1. Prior to the accumulation of 3,800 total flight cycles on that newly installed straight fuse pin, perform an eddy current inspection to detect cracking in that newly installed straight fuse pin, in accordance with the service bulletin. Repeat the inspection thereafter at intervals not to exceed 1,000 flight cycles on that newly installed straight fuse pin. Or (iii) Replace the cracked refinished straight fuse pin with a new 15-5PH fuse pin, P/N 311N5217-1. Prior to the accumulation of 14,000 total flight cycles on that newly installed 15-5PH fuse pin, perform an eddy current inspection to detect cracking in that newly installed 15-5PH pin, in accordance with the procedures described in the service bulletin. Repeat the inspection thereafter at intervals not to exceed 3,500 flight cycles on that newly installed 15-5PH fuse pin. ### (c) (c) For airplanes equipped with bulkhead fuse pins, P/N 311N5211-1: Within 3,000 flight cycles after the effective date of this AD, replace the bulkhead fuse pins with 15-5PH fuse pins, P/N 311N5217-1, in accordance with Boeing Service Bulletin 757-54A0019, Revision 5, dated March 17, 1994, and accomplish the requirements of paragraph (d) of this AD. ### (d) (d) For airplanes equipped with 15-5PH fuse pins: Prior to the accumulation of 14,000 total flight cycles on the 15-5PH fuse pins, perform an eddy current inspection to detect cracking in those 15-5PH fuse pins, in accordance with the procedures described in Boeing Service Bulletin 757-54A0019, Revision 5, dated March 17, 1994. (1) If no cracking is detected, repeat the inspection thereafter at intervals not to exceed 3,500 flight cycles on the 15-5PH fuse pin. (2) If any cracking is detected, accomplish the requirements of both paragraphs (d)(2)(i) and (d)(2)(ii) of this AD. (i) Prior to further flight, replace any cracked 15-5PH fuse pin with a new 15-5PH fuse pin, P/N 311N5217-1, in accordance with the procedures described in the service bulletin. And (ii) Prior to the accumulation of 14,000 total flight cycles on that newly installed 15-5PH fuse pin, perform an eddy current inspection to detect cracking in that newly installed 15-5PH fuse pin, in accordance with the procedures described in the service bulletin. Repeat the inspection thereafter at intervals not to exceed 3,500 flight cycles on that newly installed 15-5PH fuse pin. ### (e) (e) Fuse pins must be of the same type on the same strut. For example, a steel fuse pin having P/N 311N5067-1 may not be installed on the same strut that has a corrosion-resistant steel (CRES) fuse pin having P/N 311N5217-1 installed on that strut. However, fuse pins on one strut may differ from those on another strut, provided the fuse pins are not of mixed types on the same strut. ### (f) (f) 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, Transport Airplane Directorate. 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 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO. ### (g) (g) 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. ### (h) (h) The inspections and replacements shall be done in accordance with Boeing Service Bulletin 757-54A0019, Revision 5, dated March 17, 1994. 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. ### (i) (i) This amendment becomes effective on April 10, 1996. Issued in Renton, Washington, on March 1, 1996. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. ## Rule preamble ### Dates Effective April 10, 1996. The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of April 10, 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 Carrie Sumner, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 227-2778; fax (206) 227-1181. ### Supplementary information A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 93-16-09, amendment 39-8666 (58 FR 45044, August 26, 1993), which is applicable to certain Boeing Model 757 series airplanes, was published as a supplemental notice of proposed rulemaking in the Federal Register on June 8, 1995 (60 FR 30208). The action proposed to require: 1. Inspections to detect cracking of straight fuse pins, 2. Replacement of cracked straight fuse pins with either new 15-5PH corrosion- resistant steel fuse pins or like pins, 3. Replacement of bulkhead fuse pins with new 15-5PH corrosion-resistant steel fuse pins, and 4. Repetitive inspections of newly-installed fuse pins. (Installation of the new 15-5PH corrosion-resistant steel fuse pins would allow a longer repetitive inspection interval than was previously provided by AD 93-16-09.) Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received. All of the commenters support the proposed rule. One of the commenters, however, requests that the FAA consider revising this AD to include terminating action when Boeing finalizes its proposed pylon modification program. The commenter considers that that program, together with the replacement of the fuse pins, should constitute terminating action for the repetitive inspections that are required by this AD. The FAA acknowledges this comment, and may consider additional rulemaking once the manufacturer's pylon modification program has been developed, reviewed, and approved. 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 as proposed. There are approximately 273 Model 757 series airplanes equipped with Pratt & Whitney engines of the affected design in the worldwide fleet. The FAA estimates that 237 airplanes of U.S. registry will be affected by this AD. The actions that are currently required by AD 93-16-09 take approximately 8 work hours per fuse pin; there are 4 fuse pins per airplane. The average labor rate is approximately $60 per work hour. Based on these figures, the cost impact of the actions currently required by AD 93-16-09 on U.S. operators is estimated to be $455,040, or $1,920 per airplane, per cycle. However, since the integrity and strength of the new steel fuse pins permit longer inspection intervals, the cost impact for these inspections will actually be lessened (since the inspections are not required to be performed as frequently as they were previously required under AD 93-16-09). The new actions that are required by this new AD will take approximately 56 work hours per fuse pin to accomplish, at an average labor rate of $60 per work hour (There are 4 fuse pins per airplane). Required parts will be provided by the manufacturer at no cost to the operator. Based on these figures, the cost impact on U.S. operators of the new requirements of this AD is estimated to be $3,185,280, or $13,440 per airplane. The cost impact figures discussed above are 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 regulations adopted herein will not have substantial direct effects 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, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. 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: ## Related documents - [Proposed rule 94-NM-72-AD](https://openairdocs.org/proposed/94-NM-72-AD): Supplemental notice of proposed rulemaking; reopening of comment period, published Jun 8, 1995 Its text cites no advisory circulars or STCs. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.