[Federal Register Volume 64, Number 216 (Tuesday, November 9, 1999)]
[Proposed Rules]
[Pages 61044-61045]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-29331]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-259-AD]
RIN 2120-AA64


Airworthiness Directives; Aerospatiale Model ATR-42 and ATR-72 
Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM); rescission.

-----------------------------------------------------------------------

SUMMARY: This document proposes to rescind an existing airworthiness 
directive (AD), applicable to all Aerospatiale Model ATR-42 and ATR-72 
series airplanes, that currently requires revising the Airplane Flight 
Manual (AFM) to add specific flightcrew instructions to be followed in 
the event of failure of the first generator, which could lead to the 
loss of main battery power and result in the loss of all electrical 
power, except the emergency battery supply, during flight. Since the 
issuance of that AD, the FAA has received further information 
indicating that the incident that prompted that AD was an isolated 
case.

DATES: Comments must be received by December 9, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-259-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9 a.m. and 3 p.m., Monday through Friday, except 
Federal holidays.
    Information pertaining to this proposed rule 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 98-NM-259-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. 98-NM-259-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On April 20, 1998, the FAA issued AD 98-09-16, amendment 39-10497 
(63 FR 20064, April 23, 1998), applicable to all Aerospatiale Model 
ATR-42 and ATR-72 series airplanes, to require revising the Airplane 
Flight Manual (AFM) to add specific flightcrew instructions to be 
followed in the event of failure of one or both of the direct current 
(DC) generators. That action was prompted by issuance of mandatory 
continuing airworthiness information by a foreign civil airworthiness 
authority. The actions specified in that AD are intended to prevent 
failure of the second of two DC generators after the failure of the 
first generator. Such

[[Page 61045]]

failures, if not corrected, could lead to the loss of main battery 
power and result in the loss of all electrical power, except the 
emergency battery supply, during flight.

Actions Since Issuance of Previous Rule

    Since the issuance of that AD, the Direction Generale de l'Aviation 
Civile (DGAC), which is the airworthiness authority for France, has 
advised the FAA that the unsafe condition identified in French 
airworthiness directives AD T98-148-076(B) and AD T98-149-038(B), both 
dated March 20, 1998, was an isolated case. The DGAC advised that 
further investigation, a design review of the DC electrical system, and 
bench testing results indicate that the reset of the first failed 
generator did not contribute to the loss of the second generator. The 
DGAC concludes that there is no reason to prohibit reset of a failed 
generator, and concludes that the incident that prompted need for 
mandatory action was an isolated case. Consequently, the DGAC has 
issued French airworthiness directives 98-148-076(B) R1 and 98-149-
038(B) R1, both dated July 15, 1998, which provide cancellation notice 
of the French airworthiness directives that required the AFM revision.

FAA's Conclusions

    Since receipt and review of the DGAC information, the FAA has 
determined that it is unnecessary to require the AFM revisions required 
by AD 98-09-16.
    This proposed action would rescind AD 98-09-16. Rescission of AD 
98-09-16 would constitute only such action, and, if this proposal is 
followed by a final action, it would not preclude the agency from 
issuing another notice in the future, nor would it commit the agency to 
any course of action in the future.

Cost Impact

    The FAA estimates that 145 airplanes of U.S. registry are affected 
by AD 98-09-16. The actions that are currently required by that AD take 
approximately 1 work hour per airplane to accomplish, at an average 
labor rate of $60 per work hour. Based on these figures, the cost 
impact of the currently required actions on U.S. operators is estimated 
to be $8,700, or $60 per airplane. However, the adoption of this 
proposed rescission would eliminate those costs.
    Removal of the AFM revision required by AD 98-09-16 would take 
approximately 1 work hour per airplane to accomplish, at an average 
labor rate of $60 per work hour. Based on these figures, the cost 
impact of removal of the AFM revision is estimated to be $8,700, or $60 
per airplane.

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 removing amendment 39-10497.

AEROSPATIALE: Docket 98-NM-259-AD. Rescinds AD 98-09-16, Amendment 
39-10497.

    Applicability: All Model ATR-42 and ATR-72 series airplanes; 
certificated in any category.

    Issued in Renton, Washington, on November 3, 1999.
D.L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-29331 Filed 11-8-99; 8:45 am]
BILLING CODE 4910-13-U