AD 98-09-18 ACTIVE

This amendment adopts a new airworthiness directive (AD), applicable to certain Airbus Industrie Model A320 and A321 series airplanes, that requires replacement of two elevator aileron computers (ELAC) with ELAC s that contain new software. This amendment is prompted by a report indicating difficulty maintaining the intended flight path during landing in turbulent conditions. The actions specified by this AD are intended to prevent situations that could lead to reduced controllability of the airplane due to adverse airplane-pilot coupling characteristics.

Final rule.

98-09-18 AIRBUS INDUSTRIE: Amendment 39-10499. Docket 95-NM-143-AD.

Applicability: Model A320 and A321 series airplanes; as listed in Airbus Service Bulletin A320-27-1082, Revision 1, dated September 6, 1995; certificated in any category.

NOTE 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been 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 (b) 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 situations that could lead to reduced controllability of the airplane due to adverse airplane-pilot coupling characteristics, accomplish the following:

(a) Within 1 year after the effective date of this AD, replace the ELAC's having part numbers (P/N) 3945122307 and/or P/N C12370AA01 and located in aft electronics rack 80VU, with modified ELAC's having P/N 3945122502, in accordance with Airbus Service Bulletin A320-27-1082, dated April 25, 1995, or Revision 1, dated September 6, 1995.

NOTE 2: Airbus Service Bulletin A320-27-1082 references Sextant Service Bulletins 394512-27-014, dated August 11, 1995 (for airplanes on which Airbus Modification 24136P3436 has not been installed); and C12370A-27-001, dated May 2, 1995 (for airplanes on which Airbus Modification 24136P3436 has been installed); as additional sources of procedural service information for modification of the ELAC's.

(b) 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 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the International Branch, ANM-116.

(c) 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.

(d) The actions shall be done in accordance with Airbus Service Bulletin A320-27-1082, dated April 25, 1995, or Airbus Service Bulletin A320-27-1082, Revision 1, dated September 6, 1995. Revision 1 contains the specified effective pages:

Page Number
Revision Level
Shown on Page
Date
Shown on Page
1-2, 4-10, 12-14
1
September 6, 1995
3, 11, 15
Original
April 25, 1995

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 part 51. 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 4: The subject of this AD is addressed in French airworthiness directive (C/N) 95-203-072(B), dated October 11, 1995, as corrected by Erratum dated November 8, 1995.

(e) This amendment becomes effective on June 3, 1998.

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 Industrie Model A320 and A321 series airplanes was published in the Federal Register on January 7, 1997 (62 FR 949). That action proposed to require replacement of two elevator aileron computers (ELAC) with ELAC s that contain new software.

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 support the proposed rule.

One commenter, Airbus, does not object to the proposed AD, but offers the following comments suggesting changes for clarity and accuracy. The commenter requests that the statement of unsafe condition, "To prevent reduced controllability of the airplane due to problems associated with the ELAC, accomplish the following: . . .," be replaced with, "In order to adapt lateral control law to real flap position in case of failure/jamming of flaps, and in order to harmonize the lateral behavior between full and 3 configurations, in turbulence, of the ELAC, accomplish the following: . . . ." The commenter states that its proposed wording of the unsafe condition is supported by the fact that the improvement of the ELAC is the result of an in-service event that arose from three conditions surrounding that event:

- very strong turbulence during landing preparation;

- flaps locked between "full" and "3" configurations resulting from flaps extension under strong turbulent conditions, the monitoring of the interconnecting strut between inner and outer flap having detected an abnormal surfaces displacement; and

- an electronic centralized aircraft monitor (ECAM) procedure requesting to select slat/flap lever to "conf 3" when flaps are locked between configurations "3" and "full" (lever in position "full").
Additionally, the commenter notes that no system failure initiated the reported event. In conjunction with its request, the commenter also questions the accuracy of a number of statements made in the notice of proposed rulemaking (NPRM), such as whether the uncommanded roll angle experienced was actually as great as 30 degrees.

The FAA concurs partially. The FAA agrees that the statement of unsafe condition should be revised. However, the FAA does not agree with the commenter s suggested wording of the unsafe condition. The FAA notes that the preamble of the proposed rule indicates that the unsafe condition is due to uncommanded movements of the ailerons. The FAA finds that a more accurate statement of the unsafe condition would include the fact that it is actually associated with pilot response coupled with the handling characteristics of the airplane. In light of this, the FAA has revised the statement of unsafe condition throughout this final rule to state that the actions specifiedby this AD are intended to prevent situations that could lead to reduced controllability of the airplane due to adverse airplane-pilot coupling characteristics.

The commenter also notes that the proposed AD refers to part number C12370AAA01 in error. The FAA has revised the final rule to specify the correct part number: C12370AA01.

The commenter indicates that the referenced service bulletin has been revised from the original issue to Revision 1. The FAA acknowledges that Airbus has issued Service Bulletin A320-27-1082, Revision 1, dated September 6, 1995, since the issuance of the proposed rule. This service bulletin revision contains essentially the same information as that specified in the original issue of the service bulletin; however, the ELAC Configuration Chart (Figure 1) and the effectivity listing of the service bulletin has been revised in Revision 1 to reduce the number of affected airplanes. In light of this, the applicability of the final rule has been revisedto reference Revision 1 of the service bulletin. In addition, since compliance with either the original issue or Revision 1 of the service bulletin is acceptable, the final rule has been revised to cite Revision 1 of the service bulletin as an additional source of service information.

One commenter states that the cost impact information included in the proposed AD specifies that 108 Model A320 and A321 series airplanes would be affected. The commenter notes that no Model A321 series airplanes are currently on the U.S. Register. The FAA acknowledges this remark; however, the cost of compliance is the same regardless of whether all 108 airplanes are A320 s or some A321 s are included. The AD applies to Model A321 series airplanes, as well as Model A320 series airplanes, to ensure compliance in the event one or more affected Model A321 series airplanes is imported after the effective date of this AD.

Conclusion
After careful review of the available data, including the commentsnoted above, the FAA has determined that air safety and the public interest require the adoption of the rule with the changes previously described. 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 108 Model A320 and A321 series airplanes of U.S. registry will be affected by this AD, that it will take approximately 3 work hours per airplane to accomplish the required actions, and that the average labor rate is $60 per work hour. Required parts will be provided by the manufacturer at no cost to operators. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $19,440, or $180 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 on the 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:

The service information referenced in this AD may be obtained from Airbus Industrie, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France. This information may be examined at the Federal Aviation Administration (FAA), Transport Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

Norman B. Martenson, Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2110; fax (425) 227-1149.