[Federal Register Volume 59, Number 154 (Thursday, August 11, 1994)] [Unknown Section] [Page 0] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 94-18454] [[Page Unknown]] [Federal Register: August 11, 1994] ----------------------------------------------------------------------- DEPARTMENT OF TRANSPORTATION 14 CFR Part 39 [Docket No. 93-NM-174-AD; Amendment 39-8989; AD 94-15-18] Airworthiness Directives; Boeing Model 747 Series Airplanes AGENCY: Federal Aviation Administration, DOT. ACTION: Final rule. ----------------------------------------------------------------------- SUMMARY: This amendment supersedes an existing airworthiness directive (AD), applicable to certain Boeing Model 747 series airplanes, that currently requires that the FAA-approved maintenance inspection program include inspections which will give no less than the required damage tolerance rating (DTR) for each Structural Significant Item (SSI). This amendment requires the inclusion of additional airplanes to the candidate fleet. This amendment is prompted by a recommendation from the Airworthiness Assurance Working Group, Model 747 Structures Task Group. The actions specified by this AD are intended to ensure the continued structural integrity of the total Boeing Model 747 fleet. DATES: Effective September 12, 1994. The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of September 12, 1994. 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: Steven Fox, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue SW., Renton, Washington 98055-4056; telephone (206) 227-2777; fax (206) 227-1181. SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 93-06-01, amendment 39-8526 (58 FR 19571, April 15, 1993), which is applicable to certain Boeing Model 747 series airplanes, was published in the Federal Register on January 4, 1994 (59 FR 265). The action proposed to require that the FAA-approved maintenance inspection program be revised to include inspections which will give no less than the required damage tolerance rating (DTR) for each Structural Significant Item (SSI). That action was prompted by a recommendation from the Airworthiness Assurance Working Group, Model 747 Structures Task Group (STG). The requirements of that AD are intended to ensure the continued structural integrity of the total Boeing Model 747 fleet. Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received. One commenter supports the proposed rule. Several commenters request that the selection of airplanes in the candidate fleet be determined by the STG, which is comprised of representatives from various operators, the FAA, and Boeing. The FAA does not concur. The FAA has determined that retired airplanes, hull losses, or parked airplanes that are in the current candidate fleet must be replaced with in-service airplanes to maintain the candidate fleet size of 117 in-service airplanes. In selecting replacement airplanes for the candidate fleet, the FAA evaluates, among other factors, age and service history of in-service airplanes. The FAA will continue to consider recommendations from the STG for replacement airplanes; however, the responsibility for determining the suitability of airplanes for the candidate fleet ultimately rests with the FAA. One commenter questions the validity for including Boeing Model 747SR series airplanes in the Supplemental Structural Inspection Document (SSID) candidate fleet. This commenter states that the FAA's justification for including these airplanes was based upon the conversion of these airplanes from passenger operations to cargo operations, which the commenter alleges is incorrect. The commenter further states that the FAA needs to consider the inclusion of airplanes based upon maintenance requirements, especially airplanes that have been modified in accordance with supplemental type certificates (STC). The FAA does not concur. The FAA points out that it included certain Boeing Model 747SR series airplanes because these airplanes were no longer operated as Model 747SR series airplanes (at low gross weights and at reduced engine thrusts), not because they were converted from passenger operations to cargo operations. Since those airplanes are now operated similarly to other airplanes that are in the Boeing Model 747 SSID candidate fleet and that are operated as both freighter and passenger airplanes, the FAA has determined that they, too, should be included in the SSID candidate fleet. As noted above, the FAA considers many factors when selecting airplanes for inclusion into the candidate fleet, including age and service history of the airplane, which may be affected by modifications that were performed in accordance with STC's. Since AD 86-19-01 requires structural inspections and repairs or replacements on certain Model 747-100SR series airplanes, a number of commenters request that AD 86-19-01, Amendment 39-5395 (51 FR 29212, August 15, 1986), be revised to exclude Model 747SR series airplanes that are now included in this rulemaking action to avoid redundant requirements for inspection. One of these commenters requests that the requirement to inspect SSI's, required by AD 86-19-01, be exempt from the requirements of this AD. The FAA concurs. The FAA will, in a separate rulemaking action, revise AD 86-19-01 to exclude Model 747- 100SR series airplanes that have been included in this final rule. One commenter requests an extension in the compliance time until such time that a review of the damage tolerance rating (DTR) check forms has been completed and a revised SSID has been issued. The FAA does not concur. To extend the compliance time for this action would be inappropriate, since the FAA has determined that an unsafe condition exists and that inspections must be conducted to ensure continued safety. Additional rulemaking may be considered, however, once the DTR check forms have been reviewed and incorporated into the revised SSID. 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 128 Boeing Model 747 series airplanes of the affected design in the worldwide fleet. The FAA estimates that 87 airplanes of U.S. registry and 8 U.S. operators will be affected by this AD. Incorporation of the SSID program into an operator's maintenance program, as required by AD 93-06-01, and retained in this AD, is estimated to necessitate 1,000 work hours (per operator) at an average labor rate of $55 per work hour. Based on these figures, the total cost to the 8 affected U.S. operators to incorporate the SSID program is estimated to be $440,000, or $55,000 per U.S. operator. The recurring inspections cost, as required by AD 93-06-01, and retained in this AD, is estimated to be 1,275 work hours per airplane at an average labor rate of $55 per work hour. Based on these figures, the annual recurring cost required by AD 93-06-01, and retained in this AD, is estimated to be $6,100,875 for the affected U.S. fleet, or $70,125 per airplane. Since no new operators have been added by this AD, there will be no new costs associated with incorporating the SSID program into an operator's maintenance program. Therefore, the future economic cost impact of this AD on U.S. operators is now only the cost of the recurring inspections for these additional airplanes. The number of required work hours for the recurring inspections in this AD, as indicated above, is presented as if the accomplishment of the actions were to be conducted as ``stand alone'' action. However, in actual practice, these actions, for the most part, will be accomplished coincidentally or in combination with normally scheduled airplane inspections and other maintenance program tasks. Therefore, the actual number of necessary additional work hours will be minimal in many instances. Additionally, any costs associated with special airplane scheduling will be minimal. The total cost impact figure discussed above is 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: 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 39-8526 (58 FR 19571, April 15, 1993), and by adding a new airworthiness directive (AD), amendment 39-8989, to read as follows: 94-15-18 Boeing: Amendment 39-8989. Docket 93-NM-174-AD. Supersedes AD 93-06-01, Amendment 39-8526. Applicability: Model 747 series airplanes, as listed in Section 3.0 of Boeing Document No. D6-35022, Volumes 1 and 2, ``Supplemental Structural Inspection Document (SSID) for Model 747 Airplanes,'' Revision E, dated June 17, 1993; and manufacturer's line numbers 42, 174, 221, 231, 234, 239, 242, and 254; certificated in any category. Compliance: Required as indicated, unless accomplished previously. To ensure the continued structural integrity of the total Boeing Model 747 fleet, accomplish the following: (a) For airplanes listed in Boeing Document No. D6-35022, Volumes I and II, ``Supplemental Structural Inspection Document (SSID),'' Revision D, dated February 1992: Within 12 months after May 17, 1993 (the effective date of AD 93-06-01, Amendment 39-8526), incorporate a revision into the FAA-approved maintenance inspection program which provides no less than the required Damage Tolerance Rating (DTR) for each Structural Significant Item (SSI) listed in Boeing Document No. D6-35022, Revision D, dated February 1992. (The required DTR value for each SSI is listed in the document.) The revision to the maintenance program shall include Sections 5.0 and 6.0 of the SSID and shall be implemented in accordance with the procedures contained in those sections. Revision to the maintenance program shall be in accordance Revision D of the SSID, until Revision E of the SSID is incorporated into the FAA-approved maintenance inspection program in accordance with the requirements of paragraph (b) of this AD. (b) For airplanes listed in Boeing Document No. D6-35022, Volumes 1 and 2, ``Supplemental Structural Inspection Document (SSID) for Model 747 Airplanes,'' Revision E, dated June 17, 1993; and manufacturer's line numbers 42, 174, 221, 231, 234, 239, 242, and 254: Within 12 months after the effective date of this AD, replace the revision of the FAA-approved maintenance inspection program required by paragraph (a) of this AD with a revision that provides no less than the required DTR for each SSI listed in Boeing Document No. D6-35022, Volumes 1 and 2, ``Supplemental Structural Inspection Document (SSID) for Model 747 Airplanes,'' Revision E, dated June 17, 1993. (The required DTR value for each SSI is listed in the document.) The revision to the maintenance program shall include Sections 5.0 and 6.0 of the SSID and shall be implemented in accordance with the procedures contained in those sections. (c) Cracked structure must be repaired, prior to further flight, in accordance with an FAA-approved method. (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: 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. (f) The incorporation of the revision shall be done in accordance with Boeing Document No. D6-35022, Volumes 1 and 2, ``Supplemental Structural Inspection Document (SSID) for Model 747 Airplanes,'' Revision E, dated June 17, 1993, which contains the following list of effective pages: ------------------------------------------------------------------------ Revision letter Page No. shown on page ------------------------------------------------------------------------ List of Active Pages-............................. E Pages 1 through 21.1 ............................. ------------------------------------------------------------------------ (Note: The issue date is indicated only on the title page of Volume 1.) 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. (g) This amendment becomes effective on September 12, 1994. Issued in Renton, Washington, on July 22, 1994. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 94-18454 Filed 8-10-94; 8:45 am] BILLING CODE 4910-13-U