[Federal Register Volume 64, Number 207 (Wednesday, October 27, 1999)]
[Proposed Rules]
[Pages 57787-57789]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-28080]


=======================================================================
-----------------------------------------------------------------------

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 filed in 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-

[[Page 57789]]

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. 99-28080 Filed 10-26-99; 8:45 am]
BILLING CODE 4910-13-P