Airworthiness directives: Aerospatiale,

[Federal Register: November 9, 1999 (Volume 64, Number 216)]

[Proposed Rules]

[Page 61044-61045]

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

[DOCID:fr09no99-16]

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 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 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. 99-29331Filed11-8-99; 8:45 am]

   BILLING CODE 4910-13-U