AD 98-25-01

This amendment supersedes Airworthiness Directive (AD) 96-23-19, which currently requires installing a new flap actuator overtravel stop and a roll pin through the overtravel stop and jack screw on certain Air Tractor, Inc. (Air Tractor) Models AT-300, AT-400, and AT-500 series airplanes. This AD requires replacing the existing flap actuator overtravel stop with a new one of improved design. This AD is the result of reports of the jack screw breaking through the roll pin hole on three of the affected airplanes that were already in compliance with AD 96-23-19. The actions specified by this AD are intended to prevent interference between the flap pushrod and the aileron pushrod caused by the flap actuator overtravel nut disengaging, which could result in loss of aileron control.

Final rule.

98-25-01 AIR TRACTOR, INC.: Amendment 39-10922; Docket No. 98-CE-62-AD; Supersedes AD 96-23-19, Amendment 39-9823.

Applicability: The following model and serial numbered airplanes, certificated in any category, that do not have a part number (P/N) 70975-1 flap actuator overtravel stop installed in accordance with the REWORK INSTRUCTIONS section of Snow Engineering Co. Service Letter #165, dated May 15, 1998:

Models AT-300, AT-301, AT-302, AT-400, AT-400A, AT-401, AT-401A, AT-401B, AT-402, AT-402A, and AT-402B airplanes, serial numbers 300-0001 through 401B-1063; and

Models AT-501, AT-502, AT-502A, AT-502B, and AT-503A airplanes, serial numbers 502-0001 through 502B-0500.

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 (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 within the next 50 hours time-in-service (TIS) after the effective date of this AD, unless already accomplished.

To prevent interference between the flap pushrod and the aileron pushrod caused by the flap actuator overtravel nut disengaging, which could result in loss of aileron control, accomplish the following:

(a) Replace the existing flap actuator overtravel stop with a new one of improved design, P/N 70975-1. Accomplish this replacement in accordance with the REWORK INSTRUCTIONS section of Snow Engineering Co. Service Letter #165, dated May 15, 1998.

(b) 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.

(c) An alternative method of compliance or adjustment of the compliance time that provides an equivalent level of safety may be approved by the Manager, Fort Worth Airplane Certification Office (ACO), 2601 Meacham Boulevard, Fort Worth, Texas 76193-0150.

(1) The request shall be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and then send it to the Manager, Fort Worth ACO.

(2) Alternative methods of compliance approved in accordance with AD 96-23-19 are not considered approved as alternative methods of compliance for this AD.

NOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Fort Worth ACO.

(d) The replacement required by this AD shall be done in accordance with Snow Engineering Co. Service Letter #165, dated May 15, 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 Air Tractor Inc., P. O. Box 485, Olney, Texas 76374. Copies may be inspected at the FAA, Central Region, Office of the Regional Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri, or at the Office of the Federal Register, 800 North Capitol Street, NW, suite 700, Washington, DC.

(e) This amendment supersedes AD 96-23-19, Amendment 39-9823.

(f) This amendment becomes effective on January 19, 1999.

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 certain Air Tractor AT-300, AT-400, and AT-500 series airplanes was published in the Federal Register on July 21, 1998 (63 FR 39053). The NPRM proposed to supersede AD 96-23-19, Amendment 39-9823 (61 FR 58985, November 11, 1996), which currently requires installing a new flap actuator overtravel stop and a roll pin through the overtravel stop and jack screw on the affected airplanes.

The proposed AD would require replacing the existing flap actuator overtravel stop with a new one of improved design, part number (P/N) 70975-1. Accomplishment of the proposed action as specified in the NPRM would be in accordance with Snow Engineering Co. Service Letter #165, dated May 15, 1998.

The NPRM was the result of reports of the jack screw breaking through the roll pin hole on three of the affected airplanes that were already in compliance with AD 96-23-19.

Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were received on the proposed rule 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 1,250 airplanes in the U.S. registry will be affected by this AD, that it will take approximately 2 workhours per airplane to accomplish the replacement, and that the average labor rate is approximately $60 an hour. The manufacturer will supply parts atno cost to the owners/operators of the affected airplanes. Based on these figures, the total cost impact of this AD on U.S. operators is estimated to be $150,000, or $120 per airplane.

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 numberof 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 U.S.C. 106(g), 40113, 44701.

39.13 [Amended]
2. Section 39.13 is amended by removing airworthiness directive (AD) 96-23-19, Amendment 39-9823 (61 FR 58985, November 11, 1996), and by adding a new AD to read as follows: