Discussion
The European Aviation Safety Agency (EASA) notified us that an unsafe condition may exist on certain Airbus Model A318, A319, A320, and A321 airplanes. The EASA advises that an operator reported the failure of a fuel tank boost pump in service. Subsequent investigation revealed that one of two screws that hold the gas return connector to the top of the boost pump housing had become unscrewed. The screw fell into the boost pump motor and created a short circuit between the stator and rotor, which caused a circuit breaker to trip.
It was determined from further investigation that the screw came loose because of an inadequate screw locking mechanism and because the screw had not been tightened to the correct torque value. This failure mode was not identified during the design review conducted by the manufacturer in accordance with Special Federal Aviation Regulation No. 88 ("SFAR 88," Amendment 21-78, and subsequent Amendments 21-82 and21-83). This condition, if not corrected, could lead to a screw becoming detached, which could compromise the integrity of the explosion-proof housing of the boost pump motor and create a potential ignition source. We are issuing this AD to ensure that the flightcrew is aware of procedures to prevent the presence of a combustible air- fuel mixture in the fuel tank boost pump, which, in the event of electrical arcing in the pump motor, could result in an explosion and loss of the airplane.
Relevant Service Information
Airbus has issued Temporary Revision (TR) 4.03.00/28, dated May 4, 2006. The TR describes a revision to the Airbus A318/A319/A320/A321 AFM. The revision specifies conditions under which the center tank fuel boost pumps must be turned off to ensure that the center tank fuel boost pumps remain immersed in fuel during flight.
The EASA mandated the TR to ensure that the center fuel tank boost pumps are immersed in fuel at all times during flight. The EASA also mandated "AFM and Airworthiness limitations" to ensure that the pumps are turned off during refueling and that the pumps are immersed in fuel at all times during ground fuel transfer and defueling. The EASA issued emergency airworthiness directive 2006-0106-E, dated May 2, 2006, to ensure the continued airworthiness of these airplanes in the European Union.
FAA's Determination and Requirements of This AD
These airplane models are manufactured in France and are type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. As described in FAA Order 8100.14A, "Interim Procedures for Working with the European Community on Airworthiness Certification and Continued Airworthiness," dated August 12, 2005, the EASA has kept the FAA informed of the situation described above. We have examined the EASA's findings, evaluated all pertinent information, and determined that we need to issue an AD for products of this type design that are certificated for operation in the United States.
Therefore, we are issuing this AD to ensure that the flightcrew is aware of procedures to prevent the presence of a combustible air-fuel mixture in the fuel tank boost pump, which, in the event of electrical arcing in the pump motor, could result in an explosion and loss of the airplane. This AD requires inspecting to determine the part number and serial number of the fuel tank boost pumps and, for airplanes with affected pumps, revising the AFM to require including the information in the TR, and revising the AFM and the FAA-approved maintenance program to mandate the limitations described earlier. This AD also provides for optional terminating action for compliance with the revisions to the AFM and the maintenance program.
Differences Between the EASA Emergency Airworthiness Directive and This AD
The EASA emergency airworthiness directive specifies to revise the AFM "from the effective date of this AD;" however, this AD requires revising the AFM within 10 days after the effective date of this AD.
The EASA emergency airworthiness directive applies to Airbus Model A318, A319, A320, and A321 airplanes equipped with Eaton Aerospace Limited fuel pumps, having part number (P/N) 568-1-27202-005 with serial number (S/N) 6137 and subsequent. However, this AD applies to all Model A318, A319, A320, and A321 airplanes, and requires that operators perform an inspection to determine the P/N and S/N of the fuel tank boost pumps within 10 days after the effective date of this AD.
In addition, the EASA emergency airworthiness directive does not specify a terminating action; however, this AD specifies that replacing all subject fuel tank boost pumps with boost pumps not having the identified P/N and S/N is acceptable as an optional terminating action for compliance with the revisions specified for the AFM and maintenance program revisions.
Interim Action
We consider this AD interim action. If final action is later identified, we may consider further rulemaking then.
FAA's Determination of the Effective Date
An unsafe condition exists that requires the immediate adoption of this AD; therefore, providing notice and opportunity for public comment before the AD is issued is impracticable, and good cause exists to make this AD effective in less than 30 days.
Comments Invited
This AD is a final rule that involves requirements that affect flight safety and was not preceded by notice and an opportunity for public comment; however, we invite you to submit any relevant written data, views, or arguments regarding this AD. Send your comments to an address listed in the ADDRESSES section. Include "Docket No. FAA-2006- 24949; Directorate Identifier 2006-NM-110-AD" at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects ofthe AD that might suggest a need to modify it.
We will post all comments we receive, without change, to http://dms.dot.gov , including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this AD. Using the search function of that Web site, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you may visit http://dms.dot.gov.
Examining the Docket
You may examine the AD docket on the Internet at http://dms.dot.gov , or in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone (800) 647- 5227) is located on the plaza level of the Nassif Building at the DOT street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after the Docket Management System receives them.
Authority for This Rulemaking
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 likelyto exist or develop on products identified in this rulemaking action.
Regulatory Findings
We 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.
For the reasons discussed above, I certify that the 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 AD and placed it in the AD docket. See the ADDRESSES section for a location to examine the regulatory evaluation.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
Adoption of the Amendment
Accordingly, under the authority delegated to me by the Administrator, the FAA amends 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. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. The Federal Aviation Administration (FAA) amends Sec. 39.13 by adding the following new airworthiness directive (AD):