Airworthiness Directives; Airbus Model A310 Series Airplanes and Model A300-600 Series Airplanes

AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT).

ACTION:

Supplemental notice of proposed rulemaking (NPRM); reopening of comment period.

SUMMARY:

The FAA is revising an earlier NPRM for an airworthiness directive (AD) that applies to all Airbus Model A310 series airplanes and Model A300-600 series airplanes. The original NPRM would have required superseding two existing ADs. One existing AD applies to certain Airbus Model A310 series airplanes and currently requires repetitive inspections for cracking of the flap transmission shafts, and replacement of the transmission shafts if necessary. That existing AD also provides an optional terminating action for the repetitive inspections. The other existing AD applies to all Airbus Model A310 and A300-600 series airplanes and currently requires a one-time inspection of the trimmable horizontal stabilizer actuator, corrective actions if necessary, and follow-on repetitive tasks. The original NPRM would have added revising the Airworthiness Limitations Section of the Instructions for Continued Airworthiness to incorporate new limitations and maintenance tasks for aging systems maintenance. The original NPRM resulted from the manufacturer's determination that life limitations and maintenance tasks are necessary in order to ensure continued operational safety of the affected airplanes. This new action revises the original NPRM by reducing the initial compliance times. We are proposing this supplemental NPRM to prevent reduced structural integrity of these airplanes due to the failure of system components.

DATES:

We must receive comments on this supplemental NPRM by October 21, 2008.

ADDRESSES:

You may send comments by any of the following methods:

• Federal eRulemaking Portal: Go to http://www.regulations.gov . Follow the instructions for submitting comments.
• Fax: 202-493-2251.
• Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.
• Hand Delivery: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this AD, contact Airbus, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France.

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.gov ; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Office (telephone 800-647-5527) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

Tom Stafford, Aerospace Engineer, International Branch, ANM-116, Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 227-1622; fax (425) 227-1149.

SUPPLEMENTARY INFORMATION:

Comments Invited

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 ADDRESSES section. Include “Docket No. FAA-2008-0018; Directorate Identifier 2007-NM-145-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD because of those comments.

We 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 proposed AD.

Discussion

The FAA issued a notice of proposed rulemaking (NPRM) (the “original NPRM”) to amend 14 CFR part 39 to include an AD that supersedes two existing ADs: AD 2006-10-11, amendment 39-14595 (71 FR 28254, May 16, 2006), which applies to certain Airbus Model A310 series airplanes; and AD 2006-15-10, amendment 39-14690 (71 FR 42021, July 25, 2006), which applies to all Airbus Model A310 and A300-600 series airplanes. The original NPRM was published in the Federal Register on January 14, 2008 (73 FR 2197). The original NPRM applies to all Airbus Model A310 series airplanes and Model A300-600 series airplanes. The original NPRM proposed to retain the requirements of the existing ADs. The original NPRM also proposed to add revising the Airworthiness Limitations Section (ALS) of the Instructions for Continued Airworthiness (ICA) to incorporate new limitations and maintenance tasks for aging systems maintenance.

Actions Since Original NPRM Was Issued

Since the original NPRM was issued, we have determined that the initial compliance times for the revision specified in paragraph (o) of the original NPRM need to be reduced. In paragraph (o) of the original NPRM, we specified that for all tasks “* * * the initial compliance times start from the effective date of this AD * * *.” However, the thresholds specified in Airbus A310 ALS Part 4—Aging Systems Maintenance, Revision 01, dated December 21, 2006; and Airbus A300-600 ALS Part 4—Aging Systems Maintenance, Revision 01, dated December 21, 2006; (which are referred to as the appropriate sources of service information for accomplishing the required actions in paragraph (o) of the original NPRM); start from “* * * the initial entry into service of a specific maintenance task.”

In order to ensure timely action to address the identified unsafe condition, we have reduced the initial compliance times in order to match the service information. We have revised paragraph (o) of the supplemental NPRM accordingly.

Comments

We provided the public the opportunity to participate in the development of this AD. We have considered the comments that have been received on the original NPRM.

Request To Refer to Latest Revisions of Service Bulletins

Federal Express (FedEx) requests that we refer to the latest revision of Airbus Service Bulletin A300-27-6044, Revision 04, dated September 10, 2001; and Airbus Service Bulletin A310-27-2089, Revision 02, dated June 28, 2001 (which are referred to in Table 1 of paragraph (k) of the original NPRM as the appropriate sources of service information for doing the actions specified in paragraphs (l), (m), and (n) of the original NPRM). FedEx states that Airbus Service Bulletin A300-27-6044, Revision 05, dated August 29, 2006; and Airbus Service Bulletin A310-27-2089, Revision 03, dated August 29, 2006; do not specify any additional work and were primarily issued to adjust the service bulletin effectivity as well as to provide additional reference data.

We agree with the commenter to refer to Airbus Service Bulletin A300-27-6044, Revision 05, dated August 29, 2006; and Airbus Service Bulletin A310-27-2089, Revision 03, dated August 29, 2006. We have reviewed the service bulletins and determined no additional work is required. We have revised Table 1 of this supplemental NPRM accordingly.

Request To Clarify Definition of “New”

FedEx requests that we clarify the word “new” specified in paragraph (m) of the original NPRM. FedEx states that the word “new” pertains to the replacement of the trimmable horizontal stabilizer actuator (THSA), and the replacement could be with a new or used (serviceable) THSA provided that the THSA has not been operated more than 65,000 flight hours or 40,000 flight cycles or been in service more than 25 years since new, whichever occurs first. FedEx also states that if an THSA that was operated more than 47,000 flight hours has been installed, it must be inspected in accordance with Airbus Service Bulletins A300-27-6044 or A310-27-2089 (as specified in paragraph (n) of the original NPRM). FedEx further states that Airbus is in concurrence with FedEx's comment.

We agree with the commenter that the replacement specified in paragraph (m) of this supplemental NPRM could be with a new or serviceable THSA. Sub-part 4-2 of the Airbus A300-600 and A310 ALS Part 4 lists the life limits for the operational life of the listed components. When a component (e.g., the THSA) reaches the earliest of any of the life limits in flight hours, flight cycles, or calendar time, that component has reached the end of its given operational life and must be removed from the airplane and replaced by another unit. It is not necessary that the replacement unit/component be “new.” The rules of application for the ALS Part 4 are given in sub-part 4-0 of the ALS.

It is a requirement that a life-limited component not be operated beyond the limitation stated in the ALS Part 4-2. Thus, for the THSA, as long as none of the limits (65,000 flight hours, 40,000 flight cycles, or 25 years of operation) have been exceeded and the component is classified “serviceable,” then the component can be installed and operated on the airplane. Airbus Operators Information Telex (OIT) SE 999.0074/05/BB, dated August 3, 2005, provides clarification on these limits. We have revised paragraph (m) of this supplemental NPRM to clarify that the installed part may be “new” or “serviceable,” and we have added Note 6 and Note 7 to this supplemental NPRM to refer to the OIT for clarification of these limits.

Request To Clarify Starting Point of 25-Year Life Limit

FedEx requests that we clarify the starting point for the 25-year life limit specified in the Airbus A300-600 and A310 ALS Part 4 for THSAs built as spare parts and not originally installed on airplanes. FedEx suggests that operators be required to use the date of manufacture of the THSA as documented by Goodrich, the original equipment manufacturer (OEM) of the THSA. FedEx states that it would be difficult to determine when the component, produced as a spare by Goodrich, was first installed on an airplane.

We agree to clarify the starting point for the 25-year life limit. The ALS Part 4 does not provide the calendar limit guidance that is provided in Airbus Service Information Letter (SIL) 05-008, dated July 7, 2006. Airbus issued SIL 05-008 to give guidance (i.e., a calculation method) for life limitations in calendar parameters for components whose history is partially or completely unknown. This calculation method could be used by operators when they comply with the ALS Parts 4-2 and 4-3(a).

The SIL is intended for use when operators cannot retrieve their parts history (in flight hours/flight cycles). This method provides an estimated parts life (flight hours/flight cycles) and is very conservative. As suggested in the FedEx request, one method employed in the life calculation (starting point) is the date of manufacture (DOM). The DOM is shown in one of the tables and examples within the SIL.

The SIL is not currently referenced in the ALS Part 4. However, Airbus has issued OIT SE 999.0008/07/LB, dated January 16, 2007. Section 4 of the OIT advises users of the availability of SIL 05-008. We have added Note 8 to this supplemental NPRM to refer to the OIT and SIL for clarification.

Request To Include New THSA Part

FedEx requests that we include the new configuration of THSA, part number (P/N) 47142-323, and its life limitation. FedEx states that P/N 47142-323 does not have the 25-year life limit due to the application of enhanced materials and processes used during manufacture to reinforce their resistance to corrosion. FedEx notes that Airbus issued Service Bulletins A300-27-6058 and A310-27-2100, both dated August 30, 2007, to introduce this new THSA configuration, which does not carry a calendar life limit. FedEx further states that ALS Part 4 does not address this THSA configuration.

We do not agree to include the new THSA part number. We acknowledge that Airbus Service Bulletins A300-27-6058 (for Model A300-600 airplanes) and A310-27-2100 (for Model A310 airplanes) specify procedures to install THSA P/N 47142-323. However, Airbus has not published a revised inspection task that will apply to P/N 47142-323 to address the corrosion issue. After this task has been published, operators may request an alternative method of compliance (AMOC) according to the provisions of paragraph (r) of this supplemental NPRM. We have not revised this supplemental NPRM in this regard.

Request To Allow Additional Compliance Time

FedEx requests that we add a grace period of 1,200 flight hours for Task Number 274411-12-1. FedEx states that the task is contained within Airbus A310 ALS Part 4—Aging Systems Maintenance, Revision 01, dated December 21, 2006; and Airbus A300-600 ALS Part 4—Aging Systems Maintenance, Revision 01, dated December 21, 2006; which were referred to in paragraph (o) of the original NPRM for the incorporation of new limitations and maintenance tasks for aging systems maintenance. FedEx states that the task establishes a threshold for accomplishment at 47,000 flight hours or 20 years, whichever occurs first, but does not provide a grace period for the inspection on actuators that have exceeded 20 years in service but not yet reached 25 years in service (the established life limit of the THSA). FedEx suggests a grace period of 1,200 flight hours to provide sufficient time to sequence airplanes through maintenance for accomplishment of this THSA inspection at the new established threshold.

We agree that a grace period is necessary. In accordance with paragraph (o) of this supplemental NPRM, operators have three months to revise the ALS of the ICA to incorporate the tasks specified in Airbus A310 ALS Part 4—Aging Systems Maintenance, Revision 01, dated December 21, 2006; and A300-600 ALS Part 4—Aging Systems Maintenance, Revision 01, dated December 21, 2006; as applicable. For the initial compliance times for the tasks identified in the ALS, we have added paragraph (o)(2) of this supplemental NPRM to provide a grace period of within 3 months after revising the ALS of the ICA.

FAA's Determination and Proposed Requirements of the Supplemental NPRM

The changes discussed above expand the scope of the original NPRM; therefore, we have determined that it is necessary to reopen the comment period to provide additional opportunity for public comment on this supplemental NPRM.

Costs of Compliance

The following table provides the estimated costs for U.S. operators to comply with this supplemental NPRM.

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 likely to exist or develop on products identified in this rulemaking action.

Regulatory Findings

We have 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 that the 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 supplemental NPRM 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
• Safety

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 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.