AD 99-08-09

This amendment supersedes an existing airworthiness directive (AD), applicable to certain Aerospatiale Model ATR42-300 and -320 series airplanes, that currently requires a one-time inspection of the main landing gear (MLG) actuator fitting bolt holes for correct alignment, and rework of the fitting surface and bolt replacement, if necessary. This amendment requires replacement of the MLG actuator fitting bolts with new, improved bolts. This amendment also revises the applicability of the existing AD. 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 failure of the MLG actuator fitting bolts, which could result in the inability to retract the MLG and attain an adequate climb gradient.

Final rule

99-08-09 AEROSPATIALE: Amendment 39-11115. Docket 98-NM-175-AD. Supersedes AD 90-19-06, Amendment 39-6727 which superseded AD 89-24-08, Amendment 39-6396

Applicability: Model ATR42-200, -300 -320, and -500 series airplanes; except for airplanes on which either Aerospatiale Modification 4052 or Avions de Transport Regional Service Bulletin ATR42-53-0097, dated November 7, 1997, or Revision 1, dated January 20, 1997, has been accomplished; 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 (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 failure of the main landing gear (MLG) actuator fitting bolts, which could result in the inability to retract the MLG and attain an adequate climb gradient, accomplish the following: Required Replacement

(a) Within 10 months after the effective date of this AD, replace the MLG actuator fitting bolts with new, improved bolts in accordance with Avions de Transport Regional Service Bulletin ATR42-53-0112, dated January 20, 1998, or Revision 1, dated April 22, 1998. Alternative Methods of Compliance

(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 2: 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

(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. Incorporation by Reference

(d) The replacement shall be done in accordance with Avions de Transport Regional Service Bulletin ATR42-53-0112, dated January 20, 1998, or Avions de Transport Regional Service Bulletin ATR42-53-0112, Revision 1, dated April 22, 1998, which contains the following list of effective pages:

Page Number
Revision Level
Shown on Page
Date
Shown on Page
1, 9-11, 14, 16, 19
1
April 22, 1998
2-8, 12, 13, 15, 17, 18
Original
January 20, 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 part 51. Copies may be obtained from AI(R) American Support, Inc., 13850 Mclearen Road, Herndon, Virginia 20171. 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 3: The subject of this AD is addressed in French airworthiness directive 97-115- 070(B)R1, dated February 11, 1998.

(e) This amendment becomes effective on May 17, 1999.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 90-19-06, amendment 39-6727 (55 FR 37457, September 12, 1990), which is applicable to certain Aerospatiale Model ATR42-300 and -320 series airplanes, was published in the Federal Register on August 13, 1998 (63 FR 43335). The action proposed to require replacement of the MLG actuator fitting bolts with new, improved bolts. The action also proposed to revise the applicability of the existing AD.

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

Request to Extend Compliance Time
One commenter requests that the compliance time for accomplishment of the replacement be extended from the proposed 7 months to 13 months after the date of its letter (August 20, 1998). The commenter states that such an extension would allow the replacement to be accomplished during a regularly scheduled "heavy check", and thereby eliminate any additional expenses that would be associated with special scheduling.

The FAA concurs that the compliance times can be extended somewhat. The FAA's intent was that the replacement be conducted during a regularly scheduled maintenance visit for the majority of the affected fleet, when the airplanes would be located at a base where special equipment and trained personnel would be readily available, if necessary. Based on the information supplied by the commenter, the FAA now recognizes that 10 months corresponds more closely to the interval representative of most of the affected operators' normal maintenance schedules. Paragraph (a) of the final rule has been revised to reflect a compliance time of 10 months. The FAA does not consider that this extension will adversely affect safety. In addition, under the provisions of paragraph (b) of the final rule, the FAA may approve requestsfor adjustments to the compliance time if data are submitted to substantiate that such an adjustment would provide an acceptable level of safety.

Request to Reference Latest Service Bulletin
One commenter requests that the proposed AD be revised to reference Revision 1 of Avions de Transport Regional Service Bulletin ATR42-53-0112, dated April 22, 1998. The commenter states that Revision 1 clarifies the instructions for the replacement and description of the work to be accomplished. The FAA concurs. Since issuance of the NPRM, the Direction G n rale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, has approved and the FAA has reviewed Revision 1 of the subject service bulletin. The FAA finds that the replacement procedures specified in Revision 1 are essentially identical to those described in the original version of the service bulletin (which was referenced in the proposed AD as the appropriate source of service information for accomplishment of the replacement). Therefore, the FAA has revised paragraph (a) of the final rule to include Revision 1 of the subject service bulletin as an additional source of service information.

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 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
There are approximately 79 airplanes of U.S. registry that will be affected by this AD.

The new replacement that is required in this AD action will take approximately 12 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts will cost approximately $250 per airplane. Based on these figures, the cost impact of the required replacement of this AD on U.S. operators is estimated to be $76,630, or $970 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 removing amendment 39-6727 (55 FR 37457, September 12, 1990), and by adding a new airworthiness directive (AD), amendment 39-11115, to read as follows: