[Federal Register Volume 59, Number 152 (Tuesday, August 9, 1994)] [Unknown Section] [Page 0] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 94-19352] [[Page Unknown]] [Federal Register: August 9, 1994] ======================================================================= ----------------------------------------------------------------------- DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. 94-NM-71-AD] Airworthiness Directives; Boeing Model 757 Series Airplanes Equipped with Rolls Royce Engines 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 757 series airplanes, that currently requires repetitive inspections to detect cracking in the midspar fuse pins and replacement of certain fuse pins. This action would require inspecting straight fuse pins and replacing cracked straight fuse pins with either new corrosion- resistant steel fuse pins or like pins, replacing bulkhead fuse pins with new corrosion-resistant steel fuse pins, and repetitively inspecting newly installed fuse pins. This proposal is prompted by the development of new corrosion-resistant steel fuse pins. The actions specified by the proposed 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. DATES: Comments must be received by October 3, 1994. ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-103, Attention: Rules Docket No. 94-NM-71-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal holidays. 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: 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: 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 notice may be changed in light of the comments received. 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 notice must submit a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket Number 94-NM-71-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-103, Attention: Rules Docket No. 94-NM-71-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Discussion On August 17, 1993, the FAA issued AD 93-16-08, amendment 39-8665 (58 FR 45041, August 26, 1993), applicable to certain Boeing Model 757 series airplanes, to require repetitive inspections to detect cracking in the midspar fuse pins and replacement of certain fuse pins with new or refinished fuse pins. That action was prompted by reports of cracked fuse pins found on in-service airplanes. The requirements of that AD are intended to prevent separation of the strut and engine from the wing of the airplane. Since the issuance of that AD, the manufacturer has developed new 15-5PH corrosion-resistant steel fuse pins. Test data have shown that these new fuse pins have a longer service life. Therefore, the FAA has determined that the inspection interval for these new pins can be increased significantly without compromising safety. Further, the FAA has reviewed the service experience of affected in-service airplanes and has found that consistent quality of the fuse pins cannot be ensured during the refinishing process of the fuse pins. Consequently, refinished straight fuse pins, currently allowed by AD 93-16-08 as suitable replacement fuse pins, are no longer considered to be suitable replacements. Cracked fuse pins, if not corrected, could result in separation of the strut and engine from the wing of the airplane. The FAA has reviewed and approved Boeing Service Bulletin 757- 54A0020, Revision 5, dated March 17, 1994, which describes procedures for eddy current inspection to detect cracking in straight fuse pins, replacement of cracked straight fuse pins with either new 15-5PH pins or like pins, replacement of bulkhead fuse pins with new 15-5PH corrosion-resistant steel fuse pins, and repetitive eddy current inspections to detect cracking in the newly installed fuse pins. 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 93-16-08 to require inspection of straight fuse pins, replacement of cracked straight fuse pins with either new 15-5PH corrosion-resistant steel fuse pins or like pins, replacement of bulkhead fuse pins with new 15-5PH corrosion-resistant steel fuse pins, and repetitive inspections of newly installed fuse pins. Installation of the steel fuse pins would allow a longer repetitive inspection interval than was previously provided by AD 93- 16-08. The actions would be required to be accomplished in accordance with the service bulletin described previously. There are approximately 306 Model 757 series airplanes equipped with Rolls Royce engines of the affected design in the worldwide fleet. The FAA estimates that 119 airplanes of U.S. registry would be affected by this proposed AD. The inspections that were previously required by AD 93-16-09, and retained in this proposal take approximately 8 work hours per fuse pin at an average labor rate of $55 per work hour. There are 4 fuse pins per airplane. Based on these figures, the total cost impact of these inspections on U.S. operators is estimated to be $209,440, or $1,760 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 would actually be lessened because the proposed inspections are not required to be performed as frequently as currently required by AD 93-16-08. The proposed replacement would take approximately 56 work hours per fuse pin at an average labor rate of $55 per work hour. Required parts would be provided by the manufacturer at no cost to the operator. Based on these figures, the total cost impact of the proposed replacement on U.S. operators is estimated to be $1,466,080, or $12,320 per airplane. The total cost impact figure discussed above is 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 FAA recognizes that the obligation to maintain aircraft in an airworthy condition is vital, but sometimes expensive. Because AD's require specific actions to address specific unsafe conditions, they appear to impose costs that would not otherwise be borne by operators. However, because of the general obligation of operators to maintain aircraft in an airworthy condition, this appearance is deceptive. Attributing those costs solely to the issuance of this AD is unrealistic because, in the interest of maintaining safe aircraft, most prudent operators would accomplish the required actions even if they were not required to do so by the AD. A full cost-benefit analysis has not been accomplished for this proposed AD. As a matter of law, in order to be airworthy, an aircraft must conform to its type design and be in a condition for safe operation. The type design is approved only after the FAA makes a determination that it complies with all applicable airworthiness requirements. In adopting and maintaining those requirements, the FAA has already made the determination that they establish a level of safety that is cost-beneficial. When the FAA, as in this proposed AD, makes a finding of an unsafe condition, this means that this cost- beneficial level of safety is no longer being achieved and that the proposed actions are necessary to restore that level of safety. Because this level of safety has already been determined to be cost-beneficial, a full cost-benefit analysis for this proposed AD would be redundant and unnecessary. The regulations proposed herein would 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 proposal would not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. 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. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g); and 14 CFR 11.89. Sec. 39.13 [Amended] 2. Section 39.13 is amended by removing amendment 39-8665 (58 FR 45041, August 26, 1993), and by adding a new airworthiness directive (AD), to read as follows: Boeing: Docket 94-NM-71-AD. Supersedes AD 93-16-08, Amendment 39- 8665. - Applicability: Model 757 series airplanes equipped with Rolls Royce engines, certificated in any category. Compliance: Required as indicated, unless accomplished previously. Note 1: Inspections accomplished prior to the effective date of this amendment in accordance with the procedures described in Boeing Service Bulletin 757-54A0020, Revision 4, dated May 27, 1993, Revision 3, dated March 26, 1992, or Revision 2, dated October 31, 1991, 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) For airplanes equipped with straight fuse pins, part number (P/N) 311N5067-1: Prior to the accumulation of 5,000 total flight cycles on the straight fuse pin, perform an eddy current inspection to detect cracking in those fuse pins, in accordance with Boeing Service Bulletin 757-54A0020, Revision 5, dated March 17, 1994. (1) If no cracking is detected, repeat the inspection thereafter at intervals not to exceed 1,500 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 new straight fuse pin, P/N 311N5067-1, and prior to the accumulation of 5,000 total flight cycles on the newly installed straight fuse pin, perform an eddy current inspection, in accordance with the service bulletin. Repeat the inspection thereafter at intervals not to exceed 1,500 flight cycles on the newly installed straight fuse pin. Or (ii) Replace the cracked straight fuse pin with new 15-5PH fuse pin, P/N 311N5217-1, and prior to the accumulation of 14,000 total flight cycles on the newly installed 15-5PH fuse pin, perform an eddy current inspection to detect cracking in the newly installed pin, in accordance with the service bulletin. Repeat the inspection thereafter at intervals not to exceed 3,000 flight cycles on the newly installed fuse pin. (b) For airplanes equipped with bulkhead fuse pins, P/N 311N5211-1: Within 90 days after the effective date of this AD, replace bulkhead fuse pins with 15-5PH fuse pins, P/N 311N5217-1, in accordance with Boeing Service Bulletin 757-54A0020, Revision 5, dated March 17, 1994, and accomplish the requirements of paragraph (c) of this AD. (c) 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 fuse pins, in accordance with Boeing Service Bulletin 757-54A0020, Revision 5, dated March 17, 1994. (1) If no cracking is detected, repeat the inspection thereafter at intervals not to exceed 3,000 flight cycles on the fuse pin. (2) If any cracking is detected, accomplish the requirements of paragraphs (c)(2)(i) and (c)(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 service bulletin. (ii) Prior to the accumulation of 14,000 total flight cycles on the newly installed 15-5PH fuse pin, perform an eddy current inspection to detect cracking in the newly installed pin, in accordance with the service bulletin. Repeat the inspection thereafter at intervals not to exceed 3,000 flight cycles on the newly installed fuse pin. (d) 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 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO. (e) 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 August 2, 1994. James V. Devany, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 94-19352 Filed 8-8-94; 8:45 am] BILLING CODE 4910-13-U