AD 97-11-12

Events Leading to the Issuance of This AD A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply to ASTA Models N22B, N22S, and N24A airplanes was published in the Federal Register as a notice of proposed rulemaking (NPRM) on December 10, 1996 (61 FR 65002). The NPRM proposed to require repetitively inspecting the stub wing upper front spar cap flanges for cracks, and repairing any cracked part. Accomplishment of the proposed inspections as specified in the NPRM would be in accordance with Nomad Service Bulletin NMD-53-6, dated October 21, 1986. Accomplishment of any proposed repair (if necessary) as specified in the NPRM would be in accordance with a scheme obtained from the FAA, Los Angeles Aircraft Certification Office.

The NPRM resulted from fatigue tests that show that the stub wing upper front spar cap flanges could fail over time because of fatigue.

Interested persons have beenafforded an opportunity to participate in the making of this amendment. No comments were received on the proposed AD or the FAA's determination of the cost to the public.

The FAA's Determination After careful review of all available information related to the subject presented above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed except for minor editorial corrections. The FAA has determined that these minor corrections will not change the meaning of the AD and will not add any additional burden upon the public than was already proposed.

Cost Impact The FAA estimates that 15 airplanes in the U.S. registry will be affected by this AD, that it will take approximately 6 workhours per airplane to accomplish the required action, and that the average labor rate is approximately $60 an hour. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $5,400 or $360 per airplane. This figure does not take into account the cost of repetitive inspections or the cost to repair any cracked stub wing upper front spar cap flanges. The FAA has no way of determining the number of repetitive inspections each operator will incur over the life of each affected airplane or the number of stub wing upper front spar cap flanges that may be found cracked and need to be repaired.

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 copy of the final evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting 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 USC 106(g), 40113, 44701. 39.13 [Amended] 2. Section 39.13 is amended by adding a new airworthiness directive (AD) to read as follows: