AD 2008-04-11 R1

The FAA is revising an existing airworthiness directive (AD), which applies to all Model 707 airplanes, and Model 720 and 720B series airplanes. That AD currently requires revising the FAA-approved maintenance program by incorporating new airworthiness limitations (AWLs) for fuel tank systems to satisfy Special Federal Aviation Regulation No. 88 requirements. That AD also requires an initial inspection to phase in certain repetitive AWL inspections, and repair if necessary. This AD clarifies the intended effect of the AD on spare and on-airplane fuel tank system components. This AD results from design review of the fuel tank systems. We are issuing this AD to prevent the potential for ignition sources inside fuel tanks caused by latent failures, alterations, repairs, or maintenance actions, which, in combination with flammable fuel vapors, could result in fuel tank explosions and consequent loss of the airplane.

Final rule; request for comments.

2008-04-11 R1 The Boeing Company: Amendment 39-16147. Docket No. FAA-2009-1209; Directorate Identifier 2009-NM-151-AD. \n\nEffective Date \n\n\t(a) This airworthiness directive (AD) is effective January 12, 2010. \n\nAffected ADs \n\n\t(b) This AD revises AD 2008-04-11, Amendment 39-15383. \n\nApplicability \n\n\t(c) This AD applies to all The Boeing Company Model 707-100 long body, -200, -100B long body, and -100B short body series airplanes; Model 707-300, -300B, -300C, and -400 series airplanes; and Model 720 and 720B series airplanes; certificated in any category. \n\n\tNote 1: This AD requires revisions to certain operator maintenance documents to include new inspections. Compliance with these inspections is required by 14 CFR 91.403(c). For airplanes that have been previously modified, altered, or repaired in the areas addressed by these limitations, the operator may not be able to accomplish the actions described in the revisions. In this situation, to comply with 14 CFR 91.403(c),the operator must request approval for an alternative method of compliance according to paragraph (j) of this AD. The request should include a description of changes to the required inspections that will ensure the continued operational safety of the airplane. \n\nUnsafe Condition \n\n\t(d) This AD results from a design review of the fuel tank systems. We are issuing this AD to prevent the potential for ignition sources inside fuel tanks caused by latent failures, alterations, repairs, or maintenance actions, which, in combination with flammable fuel vapors, could result in fuel tank explosions and consequent loss of the airplane. \n\nCompliance \n\n\t(e) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done. \n\nRestatement of Requirements of AD 2008-04-11, With Changes to Compliance Method \n\nService Information \n\n\t(f) The term "D6-7552-AWL March 2006," as used in this AD, means Boeing 707/720 Airworthiness Limitations (AWLs) Document D6- 7552-AWL, dated March 2006. \n\nRevision of AWLs Section \n\n\t(g) Before December 16, 2008, revise the FAA-approved maintenance program by incorporating the information in the sections specified in paragraphs (g)(1) through (g)(3) of this AD, except that the initial inspection specified in paragraph (h) of this AD must be done at the time specified in paragraph (h). \n\t(1) Section B., "FUEL SYSTEMS AIRWORTHINESS LIMITATIONS," of D6-7552-AWL March 2006. \n\t(2) Section C., "SYSTEM AWL PAGE FORMAT," of D6-7552-AWL March 2006. \n\t(3) Section D., "AIRWORTHINESS LIMITATIONS--FUEL SYSTEMS," of D6-7552-AWL March 2006. \n\nInitial Inspection and Repair if Necessary \n\n\t(h) At the later of the times specified in paragraphs (h)(1) and (h)(2) of this AD: Do a detailed inspection of external wires over the center fuel tank for damaged or loose clamps, wire chafing, and wire bundles in contact with the surface of the center fuel tank, in accordance with Section D, "AIRWORTHINESS LIMITATIONS--FUEL SYSTEMS," AWL 28-AWL-01, of D6-7552-AWL March 2006. If any discrepancy is found during this inspection, repair the discrepancy before further flight in accordance with D6-7552-AWL March 2006. Accomplishing AWL 28-AWL-01 as part of an FAA-approved maintenance program prior to the later of the times specified in paragraphs (h)(1) and (h)(2) of this AD constitutes compliance with the requirements of this paragraph. \n\t(1) Before the accumulation of 36,000 total flight cycles, or within 120 months since the date of issuance of the original standard airworthiness certificate or the date of issuance of the original export certificate of airworthiness, whichever occurs first. \n\t(2) Within 72 months after March 28, 2008 (the effective date of AD 2008-04-11). \n\n\tNote 2: For the purposes of this AD, a detailed inspection is: "An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirror, magnifying lenses, etc., may be necessary. Surface cleaning and elaborate procedures may be required." \n\nNo Alternative Inspections, Inspection Intervals, or Critical Design Configuration Control Limitations (CDCCLs) \n\n\t(i) After accomplishing the actions specified in paragraphs (g) and (h) of this AD, no alternative inspections, inspection intervals, or CDCCLs may be used unless the inspections, intervals, or CDCCLs are approved as an alternative method of compliance (AMOC) in accordance with the procedures specified in paragraph (j) of this AD. \n\nNew Information \n\nExplanation of CDCCL Requirements \n\n\tNote 3: Notwithstanding any other maintenance or operational requirements, components that have been identified as airworthy or installed on the affected airplanes before the revision of the FAA-approved maintenance program, as required by paragraph (g) of this AD, do not need to be reworked in accordance with the CDCCLs. However, once the FAA-approved maintenance program has been revised, future maintenance actions on these components must be done in accordance with the CDCCLs. \n\nAlternative Methods of Compliance (AMOCs) \n\n\t(j)(1) The Manager, Seattle Aircraft Certification Office (SACO), FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN: Thomas Thorson, Aerospace Engineer, Propulsion Branch, ANM-140S, FAA, SACO, 1601 Lind Avenue SW., Renton, Washington 98057-3356; telephone (425) 917-6508; fax (425) 917-6590. Or, e-mail information to 9-ANM-Seattle-ACO-AMOC-Requests@faa.gov. \n\t(2) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Before using any approved AMOC on any airplane to which the AMOC applies, notify your principal maintenance inspector (PMI) or principal avionics inspector (PAI), as appropriate, or lacking a principal inspector, your local Flight Standards District Office. The AMOC approval letter must specifically reference this AD. \n\t(3) AMOCs approved previously in accordance with AD 2008-04-11, Amendment 39-15383, are approved as AMOCs for the corresponding provisions of this AD. \n\nMaterial Incorporated by Reference \n\n\t(k) You must use Boeing 707/720 Airworthiness Limitations (AWLs) Document D6-7552-AWL, including attachment, dated March 2006, to do the actions required by this AD, unless the AD specifies otherwise. \n\t(1) The Director of the Federal Register previously approved the incorporation by reference of Boeing 707/720 Airworthiness Limitations (AWLs) Document D6-7552-AWL, including attachment, dated March 2006, on March 28, 2008 (73 FR 9666, February 22, 2008). \n\t(2) For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P.O.Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone 206-544-5000, extension 1; fax 206-766-5680; e-mail me.boecom@boeing.com; Internet https://www.myboeingfleet.com. \n\t(3) You may review copies of the service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, Washington. For information on the availability of this material at the FAA, call 425-227-1221 or 425-227-1152. \n\t(4) You may also review copies of the service information that is incorporated by reference at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

Discussion \n\n\tOn February 13, 2008, we issued AD 2008-04-11, Amendment 39-15383 (73 FR 9666, February 22, 2008). That AD applied to all Model 707 airplanes, and Model 720 and 720B series airplanes. That AD required revising the FAA-approved maintenance program by incorporating new airworthiness limitations (AWLs) for fuel tank systems to satisfy Special Federal Aviation Regulation No. 88 requirements. That AD also required an initial inspection to phase in certain repetitive AWL inspections, and repair if necessary. That AD resulted from a design review of the fuel tank systems. The actions specified in that AD are intended to prevent the potential for ignition sources inside fuel tanks caused by latent failures, alterations, repairs, or maintenance actions, which, in combination with flammable fuel vapors, could result in fuel tank explosions and consequent loss of the airplane. \n\tCritical design configuration control limitations (CDCCLs) are limitation requirements to preserve a critical ignition source prevention feature of the fuel tank system design that is necessary to prevent the occurrence of an unsafe condition. The purpose of a CDCCL is to provide instruction to retain the critical ignition source prevention feature during configuration change that may be caused by alterations, repairs, or maintenance actions. A CDCCL is not a periodic inspection. \n\nActions Since AD was Issued \n\n\tSince we issued that AD, we have determined that it is necessary to clarify the AD's intended effect on spare and on-airplane fuel tank system components, regarding the use of maintenance manuals and instructions for continued airworthiness. \n\tSection 91.403(c) of the Federal Aviation Regulations (14 CFR 91.403(c)) specifies the following: \n\nNo person may operate an aircraft for which a manufacturer's maintenance manual or instructions for continued airworthiness has been issued that contains an airworthiness limitation section unless the mandatory * * * procedures * * * have been complied with. \n\nSome operators have questioned whether existing components affected by the new CDCCLs must be reworked. We did not intend for the AD to retroactively require rework of components that had been maintained using acceptable methods before the effective date of the AD. Owners and operators of the affected airplanes therefore are not required to rework affected components identified as airworthy or installed on the affected airplanes before the required revisions of the FAA-approved maintenance program. But once the CDCCLs are incorporated into the FAA- approved maintenance program, future maintenance actions on components must be done in accordance with those CDCCLs. \n\nFAA's Determination and Requirements of This AD \n\n\tThe unsafe condition described previously is likely to exist or develop on other airplanes of the same type design. For this reason, we are issuing this AD to revise AD 2008-04-11. This new AD retains the requirements of the existing AD, and adds a new note to clarify the intended effect of the AD on spare and on-airplane fuel tank system components. \n\nExplanation of Additional Changes to AD \n\n\tAD 2008-04-11 allowed the use of later revisions of the airworthiness limitations. That provision has been removed from this AD. Allowing the use of "a later revision" of specific service documents violates Office of the Federal Register regulations for approving materials that are incorporated by reference. Affected operators, however, may request approval to use a later revision of the referenced service documents as an alternative method of compliance, under the provisions of paragraph (j) of this AD. \n\tIn addition, we have revised this AD to identify the legal name of the manufacturer as published in the most recent type certificate data sheet for the affected airplane models. \n\nCosts of Compliance \n\n\tThis revision imposes no additional economic burden. The current costs for this AD are repeated for the convenience of affected operators, as follows: \n\tThere are about 213 airplanes of the affected design in the worldwide fleet. This AD affects about 76 airplanes of U.S. registry. The required actions take about 8 work hours per airplane, at an average labor rate of $80 per work hour. Based on these figures, the estimated cost of the AD for U.S. operators is $48,640, or $640 per airplane. \n\nFAA's Justification and Determination of the Effective Date \n\n\tThis revision merely clarifies the intended effect on spare and on- airplane fuel tank system components, and makes no substantive change to the AD's requirements. For this reason, it is found that notice and opportunity for prior public comment for this action are unnecessary, and good cause exists for making this amendment effective in less than 30 days. \n\nComments Invited \n\n\tThis AD is a final rule that involves requirements affecting flight safety, and we did not provide you with notice and an opportunity to provide your comments before it becomes effective. However, we invite you to send any written data, views, or arguments about this AD. Send your comments to an address listed under the ADDRESSES section. Include "Docket No. FAA-2009-1209; Directorate Identifier 2009-NM-151-AD" at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this AD. We will consider all comments received by the closing date and may amend this AD because of those comments. \n\tWe will post all comments we receive, without change, to http:// www.regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this AD. \n\nAuthority for This Rulemaking \n\n\tTitle 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority. \n\tWe are issuing this rulemaking under the authority described in subtitle VII, part A, subpart III, section 44701, "General requirements." Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action. \n\nRegulatory Findings \n\n\tWe have determined that this AD will not have federalism implications under Executive Order 13132. This AD 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. \n\tFor the reasons discussed above, I certify that the regulation: \n\t1. Is not a "significant regulatory action" under Executive Order 12866; \n\t2. Is not a "significant rule" under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and \n\t3. 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. \n\tWe prepared a regulatory evaluation of the estimated costs to comply with this AD and placed it in the AD docket. See the ADDRESSES section for a location to examine the regulatory evaluation. \n\nList of Subjects in 14 CFR Part 39 \n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. \n\nAdoption of the Amendment \n\nAccordingly, under the authority delegated to me by the Administrator, the FAA amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows: \n\nPART 39--AIRWORTHINESS DIRECTIVES \n\n1. The authority citation for part 39 continues to read as follows: \n\n\tAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\nSec. 39.13 (Amended) \n\n2. The FAA amends Sec. 39.13 by removing Amendment 39-15383 (73 FR 9666, February 22, 2008) and adding the following new AD: