AD 99-25-10

This amendment adopts a new airworthiness directive (AD), applicable to certain Airbus Model A319, A320, and A321 series airplanes, that requires a one-time inspection of the forward engine mount assembly of the left and right engines to verify that the part number on each assembly is correct; re-identification of the forward engine mount assembly; and follow-on actions, if necessary. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to prevent structural failure of the secondary load path of the forward engine mount, which, if combined with failure of the primary load path, could result in separation of the engine from the airplane.

Final rule.

99-25-10 AIRBUS INDUSTRIE: Amendment 39-11453. Docket 98-NM-284-AD.
Applicability: Model A319-131 and -132, A320-232 and -233, and A321-131 series airplanes; except those on which Airbus Modification 27020 has been accomplished (reference Airbus Service Bulletin A320-71-1021, Revision 01, dated June 10, 1998); certificated in any category.

NOTE 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been otherwise modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (c) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To prevent structural failure of the forward engine mount secondary load path, which, if combined with failure of the primary load path, could result in separation of the engine from the airplane, accomplish the following:

Inspection and Follow-On Actions
(a) Within 500 flight hours after the effective date of this AD: Perform a one-time general visual inspection of the forward engine mount assembly of the left and right engines to verify that the part number (P/N) on each assembly is correct, in accordance with Airbus Service Bulletin A320-71-1021, Revision 01, dated June 10, 1998.

NOTE 2: For the purposes of this AD, a general visual inspection is defined as "A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. Thislevel of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or drop-light, and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being check."

(1) If the P/N on the forward engine mount assembly of the left and right engines is 740-2010-513N or 740-2010-513 with a revision of `N' or higher: Within 2,250 landings following accomplishment of the inspection specified in paragraph (a) of this AD, or at the next engine removal, whichever occurs first, re-identify each assembly in accordance with the service bulletin. No further action is required by this AD.

(2) If the P/N on the forward engine mount assembly of the left and right engines is different from the P/N's specified in paragraph (a)(1) of this AD, or if the P/N cannot be determined: Prior to further flight, perform a detailed visual inspection to detect any crack or failureof the thrust links on each forward engine mount assembly, in accordance with the service bulletin.

(i) If no crack or failure of any thrust link on the left or right engine is detected: Within 2,250 landings following accomplishment of the inspection specified in paragraph (a)(2) of this AD, or at the next engine removal, whichever occurs first, modify each engine mount and its installation, and re-identify each forward engine mount assembly; in accordance with the service bulletin.

NOTE 3: Simultaneous modification of both engines is not required.

(ii) If any crack or failure of any thrust link on the left or right engine is detected, prior to further flight, replace the existing thrust link with a new thrust link, modify each engine mount, and re-identify each forward engine mount assembly; in accordance with the service bulletin.

NOTE 4: Inspection and modification of the engine mount assembly accomplished prior to the effective date of this AD in accordance with Airbus Service Bulletin A320-71-1021, dated February 6, 1998, is considered acceptable for compliance with the applicable actions specified in this AD.

NOTE 5: Airbus Service Bulletin A320-71-1021, Revision 01, dated June 10, 1998, references V2500 International Aero Engines (IAE) Service Bulletin V2500-NAC-71-0135, Revision 1, dated March 5, 1998, as an additional source of service information for accomplishment of the actions specified in this AD.

Spares
(b) As of the effective date of this AD, no person shall install a forward engine mount assembly on any airplane equipped with IAE V2500-A5 engines, unless the actions described in Airbus Service Bulletin A320-71-1021, dated February 6, 1998, or Revision 01, dated June 10, 1998, have been accomplished for that assembly.

Alternative Methods of Compliance
(c) 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, International Branch, ANM-116, 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, International Branch, ANM-116.

NOTE 6: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the International Branch, ANM-116.

Special Flight Permits
(d) 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.

Incorporation by Reference
(e) The actions shall be done in accordance with Airbus Service Bulletin A320-71- 1021, Revision 01, dated June 10, 1998. 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 part51. Copies may be obtained from Airbus Industrie, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France. 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.

NOTE 7: The subject of this AD is addressed in French airworthiness directives 98-293- 118(B), dated July 2, 1998, and 98-293-118(B) R1, dated December 16, 1998.

(f) This amendment becomes effective on January 12, 2000.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to certain Airbus Model A319, A320, and A321 series airplanes was published in the Federal Register on November 23, 1998 (63 FR 64654). That action proposed to require a one-time inspection of the forward engine mount assembly of the left and right engines to verify that the part number on each assembly is correct; re-identification of the forward engine mount assembly; and follow-on actions, if necessary.

Comments
Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received.

Two commenters state that they are not affected by the proposed rule.

Request to Extend Compliance Time for Re-identification
One commenter, the manufacturer, requests that the FAA extend the compliance time for the re-identification requirement in paragraph (a)(1) of the proposed AD from "prior to further flight" to "within 2,250 flight hours." The commenter states that such an extension would allow operators more flexibility. The commenter points out that the Direction G n rale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, is planning to revise French airworthiness directive 98-293-118(B), dated July 29, 1998 (which was referenced in the NPRM as the appropriate corresponding French airworthiness directive) on December 12, 1998, to allow this flexibility of the compliance time.

The FAA partially concurs with the commenter s request. The FAA has determined that there is no configuration difference, and therefore, it is not necessary to accomplish the re-identification prior to further flight. However, the FAA has determined that the required compliance time should be specified in terms of landings, rather than flight hours, to correspond to the compliance time specifiedin paragraph (a)(2)(i) of the AD. The FAA has revised paragraph (a)(1) of this AD to allow re-identification of the engine mounts within 2,250 landings following accomplishment of the inspection specified in paragraph (a) of this AD, or at the next engine removal, whichever occursfirst. In addition, the FAA has revised NOTE 7 (NOTE 5 of the proposed AD) of the final rule to additionally reference French airworthiness directive 98-293-118(B) R1, dated December 16, 1998.

Request to Withdraw the Re-identification Requirement
One commenter requests that the FAA not require re-identification of the mounts, as required by paragraph (a)(2) of the proposed AD, unless the configuration of the mount is altered. The commenter states that the engine mount assembly re-identification serves no purpose because there is no configuration difference between item number 740-2020-513 "N" and -517. The commenter further states that all of the mounts will be re-identified to a new part number whenimproved thrust links are installed in accordance with Airbus Service Bulletin A320-71-1020, dated May 25, 1998.

The FAA does not concur with the commenter s request. Accomplishment of Service Bulletin A320-71-1020 is required by AD 99-21-19, amendment 39-11364 (64 FR 55414, November 17, 1999). Because there is other service information that affects the engine mount part number, the FAA finds that the re-identification required by paragraph (a)(2) of the AD is important to ensure proper control of the status of the engine mounts.

Request for Relief from Removing Engines Simultaneously
One commenter requests relief from accomplishing the procedures in paragraph B (4)(b) of Airbus Service Bulletin A320-71-1021, dated February 6, 1998, or Revision 01, dated June 10, 1998, which states that both engines must be modified at the same time. The commenter notes that removal of both engines at the same time requires a flight test, which increases the cost and time out-of-service.The FAA concurs with the commenter s request. The FAA finds no technical reason for the modification of both engines to occur at the same time. However, both engines must be modified prior to 2,250 landings following accomplishment of the inspection or at the next engine removal, whichever occurs first. The FAA has added a note after paragraph (a)(2)(i) of the final rule to provide clarification regarding accomplishment of the modification for each engine.

Explanation of Change Made to Proposal
The FAA has clarified the inspection requirement contained in the proposed AD. Whereas the proposal specified a visual inspection, the FAA has revised this final rule to clarify that its intent is to require a general visual inspection. Additionally, a note has been added to the final rule to define that inspection.

Conclusion
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 with the changes described previously. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.

Cost Impact
The FAA estimates that 73 airplanes of U.S. registry will be affected by this AD, that it will take approximately 70 work hours per airplane to accomplish the required inspection, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $306,600, or $4,200 per airplane.

The 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.

Regulatory Impact
The regulations adopted herein will not have substantial direct effects on the States, on the relationship between the national government and the States, or onthe 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. 106(g), 40113, 44701.
39.13 [Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive: