AD 98-21-26

This amendment adopts a new airworthiness directive (AD) that applies to certain Mooney Aircraft Corporation (Mooney) Models M20J, M20K, M20M, and M20R airplanes. This AD requires grinding the surface of the main landing gear (MLG) leg bracket, inspecting this area for cracks, and replacing any cracked MLG leg bracket. This AD is the result of the manufacturing of several of the MLG leg brackets using laser pattern cutting. The brackets, when manufactured using this process, develop minor cracks at the bends, which could propagate over time. The actions specified by this AD are intended to prevent failure of the MLG side brace bolt caused by cracking of the MLG leg bracket, which could result in MLG collapse with consequent loss of control of the airplane during taxi, takeoff, or landing operations.

Final rule.

98-21-26 MOONEY AIRCRAFT CORPORATION: Amendment 39-10834; Docket No. 98-CE-47-AD.
Applicability: The following airplane models and serial numbers, certificated in any category:

Models
Serial Numbers
M20J
24-3415 and 24-3416
M20K
25-2018 through 25-2021
M20M
27-0241
M20R
29-0135 through 29-0138

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 in the body of this AD, unless already accomplished.

To prevent failure of the main landing gear (MLG) side brace bolt caused by cracking of the MLG leg bracket, which could result in MLG collapse with consequent loss of control of the airplane during taxi, takeoff, or landing operations, accomplish the following:

(a) Within the next 100 hours time-in-service (TIS) after the effective date of this AD, accomplish the following in accordance with the INSTRUCTIONS section of Mooney Service Bulletin M20-265, dated April 13, 1998:

(1) Grind the surface of the MLG leg bracket, part number (P/N) 510010.

(2) Inspect the area of the P/N 510010 MLG leg bracket for cracks.

(b) Prior to further flight after the inspection required by paragraph (a)(2) of this AD, replace any cracked P/N 510010 MLG leg bracket with a new P/N 510010 MLG leg bracket. Accomplish this replacement in accordance with the applicable maintenance manual.

(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) An alternative method of compliance or adjustment of the compliance times 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. The request shall be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and then send it to the Manager, Forth Worth ACO.

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.

(e) The modification and inspection required by this AD shall be done in accordance with Mooney Service Bulletin M20-265, dated April 13, 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 Mooney Aircraft Corporation, Louis Schreiner Field, Kerrville, Texas 78028. 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.

(f) This amendment becomes effective on November 26, 1998.

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 Mooney Models M20J, M20K, M20M, and M20R airplanes was published in the Federal Register as a notice of proposed rulemaking (NPRM) on June 17, 1998 (63 FR 33016). The NPRM proposed to require grinding the surface of the MLG leg bracket, part number (P/N) 510010; inspecting this area for cracks; and replacing any cracked MLG leg bracket. Accomplishment of the proposed surface grinding and inspection action as specified in the NPRM would be in accordance with Mooney Service Bulletin M20-265, dated April 13, 1998.

Replacement of any cracked MLG leg bracket, if required, would be accomplished in accordance with the applicable maintenance manual.

The NPRM was the result of the manufacturing of several of the MLG leg brackets using laser pattern cutting. The brackets, when manufactured using this process, develop minor cracks at the bends, which could propagate over time.

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 11 airplanes in the U.S. registry will be affected by this AD, that it will take approximately 8 workhours per airplane to accomplish these actions, and that the average labor rate is approximately $60 an hour. Basedon these figures, the total cost impact of this AD on U.S. operators is estimated to be $5,280, or $480 per airplane. These figures are based on the presumption that no affected airplane owner/operator has accomplished these actions. These figures do not account for the cost of any necessary replacement if any MLG leg bracket is found cracked. The FAA has no way of determining how many MLG leg brackets may be found cracked during this inspection.

Mooney will provide warranty credit for up to 8 workhours that are necessary to comply with the requirements of this AD. Details are provided in Mooney Service Bulletin M20-265, dated April 13, 1998.

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

39.13 [Amended]
2. Section 39.13 is amended by adding a new airworthiness directive (AD) to read as follows: