AD 97-15-07

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 97-15-07, which was sent previously to all known U.S. owners and operators of Aeromot-Industria Mecanico Metalurgica Ltda. (Aeromot) Model AMT-200 powered sailplanes. This AD requires immediately inspecting, using non-destructive testing (NDT) methods, the forward horizontal stabilizer front bolt, P/N 53451, for defects (scratches, damaged threads, or surface cracks, etc.), and replacing the bolt immediately if found defective or at a certain time period if not found defective. This AD was the result of a failure of the forward horizontal stabilizer bolt, part number (P/N) 53451, on one of the affected powered sailplanes. This failure was caused by a low cycle fatigue crack that was induced by over torquing the bolt. The actions specified by this AD are intended to prevent failure of the forward horizontal stabilizer bolt, which could result in separation of the horizontal stabilizer from the powered sailplane and consequent loss of control.

Final rule; request for comments

97-15-07 AEROMOT-INDUSTRIA MECANICO METALURGICA LTDA.: Amendment 39-10098; Docket No. 97-CE-66-AD.

Applicability: Model AMT-200 powered sailplanes, serial numbers 200.057, 200.058, 200.059, 200.063, 200.065, 200.066, 200.071, and 200.072, certificated in any category.

NOTE 1: This AD applies to each powered sailplane 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 powered sailplanes 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 (e) 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 after the effective date of this AD, unless already accomplished, except to those operators receiving this action by priority letter issued July 11, 1997, which made these actions effective immediately upon receipt.

To prevent failure of the forward horizontal stabilizer bolt, which could result in separation of the horizontal stabilizer from the powered sailplane and consequent loss of control, accomplish the following:

(a) Prior to further flight after the effective date of this AD, inspect, using non-destructive testing (NDT) methods, the forward horizontal stabilizer front bolt, part number (P/N) 53451, for defects (scratches, damaged threads, or surface cracks, etc.). If any defects are found, prior to further flight, replace the bolt with a new one of the same part number. Accomplish the inspection and replacement in accordance with the instructions in Aeromot Industria Ltda Service Bulletin S.B. No. 100-53-042, Issue Date: June 6, 1997; Revision Date: REV.1, July 3, 1997.

(b) Within 25 hours time-in-service (TIS) after the effective date of this AD, unless already accomplished as required by paragraph (a) of this AD, replace the forward horizontal stabilizer front bolt, P/N 53451, with a new one of the same part number. Accomplish the replacement in accordance with the instructions in Aeromot Industria Ltda Service Bulletin S.B. No. 100-53-042, Issue Date: June 6, 1997; Revision Date: REV.1, July 3, 1997.

(c) The replacement required by this AD may be accomplished prior to further flight after the effective date of this AD in place of the inspection required by paragraph (a) of this AD.

(d) Sections 61.107 (d)(1) and 61.127 (d)(1) of the Federal Aviation Regulations (14 CFR 61.107 (d)(1) and 14 CFR 61.127 (d)(1)) give flight proficiency requirements for pilots, including the assembly and disassembly of gliders and sailplanes. Therefore, the bolt replacement required by this AD may be performed by the powered sailplane owner/operator holding at least a private pilot certificate as authorized by section 43.7 of the Federal Aviation Regulations (14 CFR 43.7), and must be entered into the aircraft records showing compliance with this AD in accordance with section 43.11 of the Federal Aviation Regulations (14 CFR 43.11).

(e) An alternative method of compliance or adjustment of the compliance time that provides an equivalent level of safety may be approved by the Manager, Atlanta Aircraft Certification Office (ACO), Campus Building, 1701 Columbia Avenue, suite 2-160, College Park, Georgia 30337-2748. The request shall be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and then send it to the Manager, Atlanta ACO.

(f) The inspection and replacement required by this AD shall be done in accordance Aeromot Industria Ltda Service Bulletin S.B. No. 100-53-042, Issue Date: June 6, 1997; Revision Date: REV.1, July 3, 1997. 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 Grupo Aeromot, Aeromot-Industria Mecanico Metalurgica Ltda., Av. das Industries- 1210, Bairro Anchieta, Caixa Postal 8031, 90200-Porto Alegre-RS, Brazil. Copies may be inspected at the FAA, Central Region, Office of the Assistant Chief 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.

(g) This amendment (39-10098) becomes effective on August 15, 1997, to all persons except those persons to whom it was made immediately effective by priority letter AD 97-15-07, issued July 11, 1997, which contained the requirements of this amendment.

Events Leading to This AD
The Centro Tecnico Aeroespacial (CTA), which is the airworthiness authority for Brazil, notified the FAA that an unsafe condition may exist on certain Aeromot Model AMT-200 powered sailplanes. The CTA of Brazil reported a failure of the forward horizontal stabilizer bolt, part number (P/N) 53451. This failure was caused by a low cycle fatigue crack that was induced by over torquing the bolt.

The horizontal stabilizer bolts on the Aeromot Models AMT-100 and AMT-200 powered sailplanes are torqued with a special wrench provided by the manufacturer at delivery of the powered sailplane. When this special wrench is utilized, over torquing of these bolts is impossible. When the forward horizontal stabilizer bolt on the eight Aeromot Model AMT-200 powered sailplanes affected by this priority letter AD were torqued at the factory, this special wrench was not used and these forward horizontal stabilizer bolts were over torqued.Relevant Service Information and CTA Action
Aeromot has issued Service Bulletin S.B. No. 100-53-042, Issue Date: June 6, 1997; Revision Date: REV.1, July 3, 1997. This service bulletin includes procedures for inspecting and replacing the forward horizontal stabilizer front bolt on the affected Aeromot Model AMT-100 powered sailplanes.

The CTA for Brazil classified this service bulletin as mandatory and issued CTA EAD No. 97-07-01, in order to assure the continued airworthiness of these airplanes in Brazil.

The FAA's Determination and Explanation of the AD
Since an unsafe condition has been identified that is likely to exist or develop in other Aeromot Model AMT-200 powered sailplanes of the same type design, the FAA issued priority letter AD 97-15-07, dated July 11, 1997, to prevent failure of the forward horizontal stabilizer bolt, which could result in separation of the horizontal stabilizer from the powered sailplane and consequent loss of control. The AD requiresimmediately inspecting, using non-destructive testing (NDT) methods, the forward horizontal stabilizer front bolt, P/N 53451, for defects (scratches, damaged threads, or surface cracks, etc.), and replacing the bolt immediately if found defective or at a certain time period if not found defective.

Accomplishment of the required inspection and replacement is in accordance with Aeromot Industria Ltda Service Bulletin S.B. No. 100-53-042, Issue Date: June 6, 1997; Revision Date: REV.1, July 3, 1997. This AD also allows the option of replacing the bolt immediately instead of accomplishing the NDT inspection.

Sections 61.107 (d)(1) and 61.127 (d)(1) of the Federal Aviation Regulations (14 CFR 61.107 (d)(1) and 14 CFR 61.127 (d)(1)) give flight proficiency requirements for pilots, including the assembly and disassembly of gliders and sailplanes. Therefore, the pilot is authorized to accomplish the bolt replacement required by this AD.

Determination of the Effective Date of theAD
Since it was found that immediate corrective action was required, notice and opportunity for prior public comment thereon were impracticable and contrary to the public interest, and good cause existed to make the AD effective immediately by individual letters issued on July 11, 1997, to all known U.S. operators of Aeromot Model AMT-200 powered sailplanes. These conditions still exist, and the AD is hereby published in the Federal Register as an amendment to section 39.13 of the Federal Aviation Regulations (14 CFR 39.13) to make it effective as to all persons.

Comments Invited
Although this action is in the form of a final rule that involves requirements affecting immediate flight safety and, thus, was not preceded by notice and opportunity to comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications should identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket No. 97-CE-66-AD." The postcard will be date stamped and returned to the commenter.

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.

The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and is not a "significant regulatory action" under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, 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 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: