Airworthiness directives: Aerospatiale,

[Federal Register: October 27, 1999 (Volume 64, Number 207)]

[Proposed Rules]

[Page 57787-57789]

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

[DOCID:fr27oc99-10]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-183-AD]

RIN 2120-AA64

Airworthiness Directives; Aerospatiale Model ATR42 and ATR72 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

SUMMARY: This document proposes the adoption of a new airworthiness directive (AD) that is applicable to all Aerospatiale Model ATR42 and ATR72 series airplanes. This proposal would require modification of the alerting capability of the anti-icing advisory system to improve crew awareness of icing conditions, replacement of the median wing de-icing boots with extended de-icing boots, and installation of de-icing boots on the metallic wing leading edge. This proposal is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by the proposed AD are intended to prevent degradation of lift and drag characteristics in prolonged severe icing exposure, which could result in loss of lift and consequent reduced controllability of the airplane.

DATES: Comments must be received by November 26, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 99-NM-183-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal holidays.

The service information referenced in the proposed rule may be obtained from Aerospatiale, 316 Route de Bayonne, 31060 Toulouse, Cedex 03, France. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT: Norman B. Martenson, Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2110; fax (425) 227-1149.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications shall 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, specified above, will be considered before taking action on the proposed rule. The proposals contained in this notice may be changed in light of the comments received.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed 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 summarizing each FAA-public contact concerned with the substance of this proposal will be filedin the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket Number 99-NM-183-AD.'' The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 99-NM-183-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

The Direction Generale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, notified the FAA that an unsafe condition may exist on all Aerospatiale Model ATR42 and ATR72 series airplanes. The DGAC advises that, in several instances, crews have failed to activate the de-icing boots, despite the fact that ice accretion had been detected by the Anti-icing Advisory System (AAS). This failure to activate the de-icing boots may indicate that the current design of the AAS may not provide adequate alerting to the flight crew in all instances of ice accretion. In addition, the existing wing de-icing boots may not be adequate to protect the airplane during prolonged exposure to severe icing conditions. Such prolonged exposure could result in degradation of lift and drag characteristics, which could result in loss of lift and consequent reduced controllability of the airplane.

Explanation of Relevant Service Information

Aerospatiale has issued Service Bulletins ATR42-30-0064, Revision 1, dated May 7, 1999, and ATR42-30-0063, Revision 1, dated May 7, 1999 (for Model ATR42 series airplanes); and Service Bulletins ATR72-30- 1032, Revision 1, dated May 7, 1999, and ATR72-30-1033, Revision 1, dated May 7, 1999 (for Model ATR72 series airplanes). These service bulletins describe procedures for replacing the median wing de-icing boots with extended de-icing boots and installing de-icing boots on the metallic wing leading edge.

Additionally, Aerospatiale has issued Service Bulletin ATR42-30- 0065, Revision 1, dated May 17, 1999 (for Model ATR42 series airplanes), and Service Bulletin ATR72-30-1034, Revision 1, dated May 17, 1999 (for Model ATR72 series airplanes). These service bulletins describe procedures for modifying the ICING light flashing logic of the AAS.

Accomplishment of the actions specified in the service bulletins is intended to adequately address the identified unsafe condition. The DGAC classified these service bulletins as mandatory and issued French

[[Page 57788]]

airworthiness directives 1999-165-077(B), dated April 21, 1999 (for Model ATR42 series airplanes), and 1999-166-041(B), dated April 21, 1999 (for Model ATR72 series airplanes), in order to assure the continued airworthiness of these airplanes in France.

FAA's Conclusions

These airplane models are manufactured in France and are type certificated for operation in the United States under the provisions of Sec. 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, the DGAC has kept the FAA informed of the situation described above. The FAA has examined the findings of the DGAC, 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.

Explanation of Requirements of Proposed Rule

Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design registered in the United States, the proposed AD would require accomplishment of the actions specified in the service bulletins described previously.

Cost Impact

The FAA estimates that 140 airplanes of U.S. registry would be affected by this proposed AD.

The proposed replacement of existing de-icing boots and the new installation of de-icing boots would take approximately 75 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts would cost approximately $5,500 per airplane. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $1,400,000, or $10,000 per airplane.

The proposed modification of the alerting capability of the Anti- icing Advisory System (AAS) would take approximately 30 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts would cost approximately $2,000 per airplane. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $532,000, or $3,800 per airplane.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted.

Regulatory Impact

The regulations proposed herein would 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 proposal would not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

For the reasons discussed above, I certify that this proposed regulation (1) is not a ``significant regulatory action'' under Executive Order 12866; (2) is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, 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 draft regulatory 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, Safety.

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 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.

   Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive:

   Aerospatiale: Docket 99-NM-183-AD.

   Applicability: All Model ATR42 and ATR72 series airplanes, certificated in any category.

   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, unless accomplished previously.

   To prevent degradation of lift and drag characteristics in prolonged severe icing exposure, which could result in loss of lift and consequent reduced controllability of the airplane, accomplish the following:

   Boot Replacement/Installation

   (a) Within 30 months after the effective date of this AD, replace the median wing de-icing boots with extended de-icing boots in accordance with Aerospatiale Service Bulletin ATR42-30-0063, Revision 1, dated May 7, 1999 (for Model ATR42 series airplanes), or ATR72-30-1032, Revision 1, dated May 7, 1999 (for Model ATR72 series airplanes); as applicable.

   (b) Within 30 months after the effective date of this AD, install de-icing boots on the metallic wing leading edge in accordance with Aerospatiale Service Bulletin ATR42-30-0064, Revision 1, dated May 7, 1999 (for Model ATR42 series airplanes), or ATR72-30-1033, Revision 1, dated May 7, 1999 (for Model ATR72 series airplanes); as applicable.

   Modification

   (c) Within 30 months after the effective date of this AD, modify the ICING light flashing logic of the Anti-icing Advisory System (AAS), in accordance with Aerospatiale Service Bulletin ATR42-30- 0065, Revision 1, dated May 17, 1999 (for Model ATR42 series airplanes), or Aerospatiale Service Bulletin ATR72-30-1034, Revision 1, dated May 17, 1999 (for Model ATR72 series airplanes); as applicable.

   Alternative Methods of Compliance

   (d) 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, International Branch, ANM-116, FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, International Branch, ANM-116.

   Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the International Branch, ANM-116.

   Special Flight Permits

   (e) Special flight permits may be issued in accordance with Secs. 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.

   Note 3: The subject of this AD is addressed in French airworthiness directives 1999-

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   165-077(B), dated April 21, 1999 (for Model ATR42 series airplanes), and 1999-166-041(B), dated April 21, 1999 (for Model ATR72 series airplanes).

   Issued in Renton, Washington, on October 21, 1999. D.L. Riggin, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

   [FR Doc. 99-28080Filed10-26-99; 8:45 am]

   BILLING CODE 4910-13-P