Federal Aviation Administration (FAA), DOT.
Notice of proposed rulemaking (NPRM).
We propose to adopt a new airworthiness directive (AD) for the products listed above. This proposed AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as:
While they were gaining access to the THS (trimmable horizontal stabilizer) fuel tank for maintenance check, several operators have found one or several of the 8 THS hoist point fitting bases cracked or broken-off. The breakage resulted in metallic debris being released within the Trim Tank. The origin of the damage is most probably due to interference with the THS hoisting lugs that are stowed in the hoist point fittings in the reverse position, being screwed too deep inside the THS hoist fittings. Damaged hoist point fittings could cause the release of metallic debris within the THS fuel system.
* * * Compliance with the requirements of this AD will also eliminate potential contributing factor[s] to ignition risks.
We must receive comments on this proposed AD by July 18, 2007.
You may send comments by any of the following methods:
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You may examine the AD docket on the Internet at
Tom Stafford, Aerospace Engineer, International Branch, ANM–116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98057–3356; telephone (425) 227–1622; fax (425) 227–1149.
The FAA is implementing a new process for streamlining the issuance of ADs related to MCAI. This streamlined process will allow us to adopt MCAI safety requirements in a more efficient manner and will reduce safety risks to the public. This process continues to follow all FAA AD issuance processes to meet legal, economic, Administrative Procedure Act, and
This proposed AD references the MCAI and related service information that we considered in forming the engineering basis to correct the unsafe condition. The proposed AD contains text copied from the MCAI and for this reason might not follow our plain language principles.
We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the
We will post all comments we receive, without change, to
The European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Community, has issued EASA Airworthiness Directive 2007–0024, dated January 25, 2007 (referred to after this as “the MCAI”), to correct an unsafe condition for the specified products. The MCAI states:
While they were gaining access to the THS (trimmable horizontal stabilizer) fuel tank for maintenance check, several operators have found one or several of the 8 THS hoist point fitting bases cracked or broken-off. The breakage resulted in metallic debris being released within the Trim Tank. The origin of the damage is most probably due to interference with the THS hoisting lugs that are stowed in the hoist point fittings in the reverse position, being screwed too deep inside the THS hoist fittings. Damaged hoist point fittings could cause the release of metallic debris within the THS fuel system.
This Airworthiness Directive (AD) requires the repair of any damaged THS hoist point fittings to prevent any risk of further hoist point fittings damage as well as any fuel leak. Compliance with the requirements of this AD will also eliminate potential contributing factor[s] to ignition risks.
Airbus has issued Service Bulletins A300–55–6041, and A310–55–2042, both dated September 13, 2006. The actions described in this service information are intended to correct the unsafe condition identified in the MCAI.
This product has been approved by the aviation authority of another country, and is approved for operation in the United States. Pursuant to our bilateral agreement with the State of Design Authority, we have been notified of the unsafe condition described in the MCAI and service information referenced above. We are proposing this AD because we evaluated all pertinent information and determined an unsafe condition exists and is likely to exist or develop on other products of the same type design.
We have reviewed the MCAI and related service information and, in general, agree with their substance. But we might have found it necessary to use different words from those in the MCAI to ensure the AD is clear for U.S. operators and is enforceable. In making these changes, we do not intend to differ substantively from the information provided in the MCAI and related service information.
We might also have proposed different actions in this AD from those in the MCAI in order to follow FAA policies. Any such differences are highlighted in a NOTE within the proposed AD.
Based on the service information, we estimate that this proposed AD would affect about 137 products of U.S. registry. We also estimate that it would take about 10 work-hours per product to comply with the basic requirements of this proposed AD. The average labor rate is $80 per work-hour. Required parts would cost about $332 per product. Based on these figures, we estimate the cost of the proposed AD on U.S. operators to be $155,084, or $1,132 per product.
Title 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.
We 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.
We determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would 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.
For the reasons discussed above, I certify 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. 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.
We prepared a regulatory evaluation of the estimated costs to comply with this proposed AD and placed it in the AD docket.
Air transportation, Aircraft, Aviation safety, Safety.
Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows:
1. The authority citation for part 39 continues to read as follows:
49 U.S.C. 106(g), 40113, 44701.
2. The FAA amends § 39.13 by adding the following new AD:
(a) We must receive comments by July 18, 2007.
(b) None.
(c) This AD applies to Airbus Model A310–300 and A300–600R series airplanes; certificated in any category; all serial numbers fitted with a THS (trimmable horizontal stabilizer) containing fuel on which, during production Airbus Modifications 04801 and 04802 have been embodied, and Airbus Modification 06549 has not been embodied; except aircraft on which Airbus Modification 13191 has been embodied in production, or Airbus Service Bulletin A310–55–2042 or A300–55–6041 has been incorporated in service.
(d) Stabilizers.
(e) The mandatory continuing airworthiness information (MCAI) states:
While they were gaining access to the THS (trimmable horizontal stabilizer) fuel tank for maintenance check, several operators have found one or several of the 8 THS hoist point fitting bases cracked or broken-off. The breakage resulted in metallic debris being released within the Trim Tank. The origin of the damage is most probably due to interference with the THS hoisting lugs that are stowed in the hoist point fittings in the reverse position being screwed too deep inside the THS hoist fittings. Damaged hoist point fittings could cause the release of metallic debris within the THS fuel system.
This Airworthiness Directive (AD) requires the repair of any damaged THS hoist point fittings to prevent any risk of further hoist point fittings damage as well as any fuel leak. Compliance with the requirements of this AD will also eliminate potential contributing factor[s] to ignition risks.
(f) Unless already done, within 60 months after the effective date of this AD, do the actions specified in paragraphs (f)(1) through (f)(6) of this AD in accordance with the instructions given in Airbus Service Bulletin A300–55–6041 or A310–55–2042, both dated September 13, 2006, as applicable.
(1) Remove the 8 THS metallic hoisting lugs.
(2) Do a detailed visual inspection of the internal base of the 8 THS hoist point fittings in order to detect visible signs of score, cracks, perforation or other damage.
(3) In case of no finding, install the new plastic plugs.
(4) In case of any finding, entry into the fuel trim tank is required to do a detailed visual inspection for structural damage of the hoist point fittings base inside the fuel tank.
(5) If structural damage is not confirmed, blend-out/protect the scoring area of the fitting internal base and install the new plastic plugs.
(6) If structural damage is confirmed, repair the damaged fittings and install the new plastic plugs.
This AD differs from the MCAI and/or service information as follows: No differences.
(g) The following provisions also apply to this AD:
(1)
(2)
(3)
(h) Refer to MCAI European Aviation Safety Agency Airworthiness Directive 2007–0024, dated January 25, 2007; and Airbus Service Bulletins A300–55–6041 and A310–55–2042, both dated September 13, 2006; for related information.