AD 98-11-23

This amendment adopts a new airworthiness directive (AD), applicable to certain CASA Model CN-235 series airplanes, that requires modification of certain fastener holes of the center wing. 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 fatigue cracking in this area, which could result in reduced structural integrity of the wing.

Final rule

98-11-23 CONSTRUCCIONES AERONAUTICAS S.A. (CASA): Amendment 39-10548. Docket 97-NM-43-AD.
Applicability: Model CN-235 series airplanes; as listed in CASA Service Bulletins SB-235-57-14, Revision 1, dated June 21, 1996; and SB-235-57-05, Revision 2, dated June 21, 1996, including Annex 1, dated June 10, 1993; and Model CN-235 having serial number C-011; 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 (d) 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 fatigue cracking in the fastener holes of the center wing, which could result in reduced structural integrity of the wing, accomplish the following:

(a) For airplanes listed in CASA Service Bulletins SB-235-57-14, Revision 1, dated June 21, 1996; and SB-235-57-05, Revision 2, dated June 21, 1996, including Annex 1, dated June 10, 1993: Perform a rototest inspection of the fastener holes of the center wing to detect cracking, in accordance with the applicable service bulletin, at the time specified in paragraph (c) of this AD.

(1) If no crack is found, prior to further flight, cold work the fastener holes in accordance with the applicable service bulletin.

(2) If any crack is found, prior to further flight, remove it in accordance with the service bulletin; repeat the rototest inspection to detect cracking; and cold work the fastener holes, in accordance with the applicable service bulletin. If any crack is found that cannot be removed using the procedures specified in the applicable service bulletin, prior to further flight, repair it in accordance with a method approved by the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate.

(b) For airplane serial number C-011: Perform a rototest inspection of the fastener holes of the center wing to detect cracking, in accordance with CASA Service Bulletin SB-235-57-05, Revision 2, dated June 21, 1996, including Annex 1, dated June 10, 1993, at the time specified in paragraph (c) of this AD.

(1) If no crack is found, prior to further flight, cold work the fastener holes in accordance with the service bulletin.

(2) If any crack is found, prior to further flight, remove it in accordance with the service bulletin; repeat the rototest inspection to detect cracking; and cold work the fastener holes, in accordance with the service bulletin. If any crack is found that cannot be removed using the procedures specified in the service bulletin, prior to further flight, repair it in accordance with a method approved by the Manager, International Branch, ANM-116.

(c) Accomplish the inspection required by paragraph (a) or (b) of this AD, as applicable, at the later of the times specified in paragraphs (c)(1) and (c)(2) of this AD.

(1) Prior to the accumulation of 17,000 total flight cycles or 37,400 total flight hours, whichever occurs first.

(2) Within 6 months after the effective date of this AD.

(d) 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. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send itto 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.

(e) 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.

(f) The actions shall be done in accordance with CASA Service Bulletin SB-235-57-14, Revision 1, dated June 21, 1996, and CASA Service Bulletin SB-235-57-05, Revision 2, dated June 21, 1996, including Annex 1, dated June 10, 1993, which contains the following list of effective pages:

Page Number
Revision Level
Shown on Page
Date
Shown on Page
1, 3-5, 12, 26-29,
33, 34, 45-52
2
June 21, 1996
2, 6-11, 13-25,
30-32, 35-44,
53-65
1
March 13, 1995

Annex 1

1-46
5
June 10, 1993

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 Construcciones Aeronauticas, S.A., Getafe, Madrid, Spain. 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 Spanish airworthiness directive 04/94, dated August 1994.

(g) This amendment becomes effective on July 8, 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 CASA Model CN-235 series airplanes was published in the Federal Register on March 23, 1998 (63 FR 13801). That action proposed to require modification of certain fastener holes of the center wing.

Comments
Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were submitted in response to the proposal or the FAA's determination of the cost to the public.

Explanation of Changes Made to This Final Rule
In the proposal, the FAA inadvertently omitted reference to Annex 1, dated June 10, 1993, of CASA Service Bulletin SB-235-57-05, Revision 2, dated June 21, 1996. Therefore, the FAA has revised the final rule accordingly.

Conclusion
The FAA has determined that air safety and the public interest require the adoption of the rule with the change previously described. The FAA has determined that this change will neither increase the economic burden on any operator nor increase the scope of the AD.

Cost Impact
The FAA estimates that 2 airplanes of U.S. registry will be affected by this AD.

The FAA estimates that the actions specified in CASA Service Bulletin SB-235-57-14, will be required to be accomplished on one airplane of U.S. registry. These required actions will take approximately 220 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts will cost approximately $719 per airplane. Based on these figures, the cost impact of the inspection required by this AD on the single U.S. operator is estimated to be $13,919.

For CASA Model CN-235 series airplane, serial number C-011, on which the actions specified in CASA Service Bulletin SB-235-57-05 will be required to be accomplished, those required actions will take approximately 1,900 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts will cost approximately $11,330 per airplane. Based on these figures, the cost impact of the required actions for that airplane is estimated to be $125,330.

The cost impact figures discussed above are 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 toread 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: