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Airworthiness Directives; Agusta Model A109A, A109AII, and A109C Helicopters

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Federal Aviation Administration, DOT.


Final rule; request for comments.


This amendment adopts a new airworthiness directive (AD) applicable to Agusta Model A109A, A109AII, and A109C helicopters. This action requires inspecting the main transmission to determine if certain Gleason crowns are installed and replacing any unairworthy Gleason crown with an airworthy Gleason crown. This amendment is prompted by the discovery of a cracked Gleason crown during an unscheduled transmission inspection prompted by abnormal noises coming from the transmission during main rotor deceleration. The actions specified in this AD are intended to prevent failure of the main transmission, loss of rotor drive, and subsequent loss of control of the helicopter.


Effective May 1, 2000.

Comments for inclusion in the Rules Docket must be received on or before June 13, 2000.


Submit comments in triplicate to the Federal Aviation Administration (FAA), Office of the Regional Counsel, Southwest Region, Attention: Rules Docket No. 99-SW-47-AD, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137.

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Shep Blackman, Aerospace Engineer, FAA, Rotorcraft Directorate, Rotorcraft Standards Staff, 2601 Meacham Blvd., Fort Worth, Texas 76137, telephone (817) 222-5296, fax (817) 222-5961.

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The Registro Aeronautico Italiano (RAI), the airworthiness authority for Italy, notified the FAA that an unsafe condition may exist on Agusta Model A109A, A109AII, and A109C helicopters. The RAI reported that abnormal noises coming from the transmission during main rotor deceleration led to a transmission inspection and the discovery of a cracked Gleason crown.

Agusta has issued Bollettino Technico No. 109-109, dated June 3, 1999 (BT), which specifies inspection of the Gleason crown, part number (P/N) 109-0403-07, of the main transmission assembly, P/N 109-0400-02-5 or 109-0400-03-105. The RAI classified this BT as mandatory and issued AD 99-267, dated June 10, 1999, to ensure the continued airworthiness of these helicopters in Italy. Although the RAI permits operators to monitor the main transmissions for abnormal noises and conduct periodic airworthiness inspections until 900 hours or more time-in-service have been accrued, the FAA does not concur that “noises” are a reliable indicator of impending failure.

These helicopter models are manufactured in Italy and are type certificated for operation in the United States under the provisions of § 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, the RAI has kept the FAA informed of the situation described above. The FAA has examined the findings of the RAI, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.

Since an unsafe condition has been identified that is likely to exist or develop on other helicopters of these same type designs registered in the United States, this AD is being issued to prevent failure of the main transmission, loss of rotor drive, and subsequent loss of control of the helicopter. This AD requires inspecting the main transmission to determine if certain Gleason crowns are installed and replacing them with airworthy Gleason crowns before further flight. The short compliance time involved is required because the previously described critical unsafe condition can adversely affect the structural integrity and controllability of the helicopter. Therefore, inspecting the main transmission to determine if certain Gleason crowns are installed and replacing these certain Gleason crowns with an airworthy Gleason crown is required before further flight and this AD must be issued immediately.

Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for public comment hereon are impracticable and that good cause exists for making this amendment effective in less than 30 days.

The FAA estimates that 8 helicopters will be affected by this AD, that it will take approximately 14 work hours to Start Printed Page 20082inspect and replace the Gleason crown, and that the average labor rate is $60 per work hour. Required parts will cost approximately $7500 per helicopter. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $66,720.

Comments Invited

Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public 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 under the caption ADDRESSES. 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. 99-SW-47-AD.” The postcard will be date stamped and returned to the commenter.

The regulations adopted herein will not have a substantial direct effect 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, it is determined that this final rule does not have federalism implications under Executive Order 13132.

The FAA has also determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and that it 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 FR 11034, 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.

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List of Subjects in 14 CFR Part 39

  • Air transportation
  • Aircraft
  • Aviation safety
  • Safety
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Adoption of the Amendment

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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:

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1. The authority citation for part 39 continues to read as follows:

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Authority: 49 U.S.C. 106(g), 40113, 44701.

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2. Section 39.13 is amended by adding a new airworthiness directive to read as follows:

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AD 2000-08-02 Agusta: Amendment 39-11688. Docket No. 99-SW-47-AD.

Applicability: Model A109A, A109AII, and A109C helicopters, Serial Number (S/N) 7630, 7633, 7654, 7667, 7671, 7672, 7676, or 7677 with main transmission, part number (P/N) 109-0400-02-5 or 109-0400-03-105, with Gleason crown, P/N 109-0403-07, installed, certified in any category.

Note 1:

This AD applies to each helicopter identified in the preceding applicability provision, regardless of whether it has been otherwise modified, altered, or repaired in the area subject to the requirements of this AD. For helicopters 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 as indicated, unless accomplished previously.

To prevent failure of the main transmission, loss of rotor drive, and subsequent loss of control of the helicopter, accomplish the following:

(a) Before further flight, determine if a transmission with a S/N specified in Table 1 is installed.

Table 1

Transmission P/NTransmission S/NGleason Crown S/N

(b) If the installed Gleason crown, P/N 109-0403-07, S/N is listed in Table 1, before further flight, replace it with an airworthy Gleason crown, P/N 109-0403-07-103, S/N B58264 or subsequent, except S/N B58271.

(1) After installing the replacement Gleason crown, mark the nomenclature “S.M. 109254” on the “Modification Incorporated” area of the additional nameplate, P/N MS27253-2. Update the main transmission “Assembly Historical Record” or equivalent record, with the P/N and S/N of the Gleason crown installed.

(2) If not previously bonded to the transmission, bond the additional nameplate, P/N MS27253-2, with adhesive EA934NA below the main transmission nameplate.

Note 2:

Agusta Bollettino Technico 109-109, dated June 3, 1999, pertains to the subject of this AD.

(c) 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, Regulations Group, Rotorcraft Directorate, FAA. Operators shall submit their requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Regulations Group.

Note 3:

Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Regulations Group.

(d) Special flight permits may be issued in accordance with §§ 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the helicopter to a location where the requirements of this AD can be accomplished.

(e) This amendment becomes effective on May 1, 2000.

Note 4:

The subject of this AD is addressed in Registro Aeronautico Italiano (Italy) AD 99-267, dated June 10, 1999.

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Issued in Fort Worth, Texas, on April 7, 2000.

Henry A. Armstrong,

Manager, Rotorcraft Directorate, Aircraft Certification Service.

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[FR Doc. 00-9359 Filed 4-13-00; 8:45 am]