[Federal Register Volume 59, Number 86 (Thursday, May 5, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-10777]


[[Page Unknown]]

[Federal Register: May 5, 1994]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 94-NM-39-AD]

 

Airworthiness Directives; Israel Aircraft Industries (IAI) Model 
1125 Westwind Astra Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain IAI Model 1125 Westwind 
Astra airplanes. This proposal would require relocation of the ground 
cable in the slat power drive unit. This proposal is prompted by a 
report that the drive system for the leading edge slat stopped in 
transit during flight on a Model 1125 Westwind Astra airplane. This 
incident was caused by an improper ground connection for the electric 
motor of the slat drive system, which resulted in arcing and an open 
electrical circuit. The actions specified by the proposed AD are 
intended to prevent possible fuel vapor fire due to electrical arcing 
in an area where fuel vapors might be present and the inability to move 
the slats during flight due to an open electrical circuit.

DATES: Comments must be received by June 29, 1994.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 94-NM-39-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.
    The service information referenced in the proposed rule may be 
obtained from Astra Jet Corporation, Technical Publications, 77 
McCullough Drive, suite 11, New Castle, Delaware 19720-9813. This 
information may be examined at the FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT: Tim Dulin, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue SW., Renton, Washington 98055-4056; telephone (206) 
227-2141; fax (206) 227-1320.

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 94-NM-39-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-103, Attention: Rules 
Docket No. 94-NM-39-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The Civil Aviation Administration of Israel (CAAI), which is the 
airworthiness authority for Israel, recently notified the FAA that an 
unsafe condition may exist on certain Israel Aircraft Industries (IAI) 
Model 1125 Westwind Astra airplanes. The CAAI advises that it has 
received a report that the drive system for the leading edge slat 
stopped in transit during flight on a Model 1125 Westwind Astra 
airplane. The cause of this incident has been attributed to an improper 
ground connection for the electric motor of the leading edge slat drive 
system, which resulted in arcing and an open electrical circuit. The 
ground connection for the electric motor is located in the area just 
forward of the wing spar. Since the fuel system is integrated into the 
structure of the wing, the area is subject to fuel leakage. An improper 
ground connection for the subject motor, if not corrected, could result 
in possible fuel vapor fire due to electrical arcing in an area where 
fuel vapors might be present, and the inability to move the slats 
during flight due to an open electrical circuit.
    Astra Jet Corporation has issued Service Bulletin SB 1125-27-110, 
Revision 1, dated February 16, 1994, that describes procedures for 
relocation of the ground cable in the slat power drive unit 
(Modification 6350). Accomplishment of this modification involves 
routing the ground cable for the slat power drive located in the 
aircraft secondary structure to the aircraft primary structure. 
Relocating the ground cable will improve electrical grounding for the 
slat power drive unit. The CAAI classified this service bulletin as 
mandatory and issued Airworthiness Directive No. 93-02, dated December 
2, 1993, in order to assure the continued airworthiness of these 
airplanes in Israel.
    This airplane model is manufactured in Israel and is type 
certificated for operation in the United States under the provisions of 
Sec. 21.29 of the Federal Aviation Regulations and the applicable 
bilateral airworthiness agreement. Pursuant to this bilateral 
airworthiness agreement, the CAAI has kept the FAA informed of the 
situation described above. The FAA has examined the findings of the 
CAAI, 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 airplanes of the same type design registered 
in the United States, the proposed AD would require relocation of the 
ground cable in the slat power drive unit. The actions would be 
required to be accomplished in accordance with the service bulletin 
described previously.
    The FAA estimates that 52 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 3 work 
hours per airplane to accomplish the proposed actions, and that the 
average labor rate is $55 per work hour. Required parts would cost 
approximately $53 per airplane. Based on these figures, the total cost 
impact of the proposed AD on U.S. operators is estimated to be $11,336, 
or $218 per airplane.
    The total cost impact figure discussed above is 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.
    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 14 
CFR part 39 of the Federal Aviation Regulations as follows:

PART 39--AIRWORTHINESS DIRECTIVES

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

    Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13  [Amended]

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

Israel Aircraft Industries Limited: Docket 94-NM-39-AD.

    Applicability: Model 1125 Westwind Astra airplanes; serial 
numbers 004 through 066 inclusive, and 068; certificated in any 
category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent possible fuel vapor fire due to electrical arcing in 
an area where fuel vapors might be present and the inability to move 
the slats during flight due to an open electrical circuit, 
accomplish the following:
    (a) Within 50 hours time-in-service after the effective date of 
this AD, relocate the ground cable in the slat power drive unit in 
accordance with Astra Jet Service Bulletin SB 1125-27-110, Revision 
1, dated February 16, 1994.
    (b) 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, Standardization Branch, ANM-113, 
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, 
Standardization Branch, ANM-113.

    Note: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Standardization Branch, ANM-113.

    (c) Special flight permits may be issued in accordance with 
Federal Aviation Regulations (FAR) 21.197 and 21.199 to operate the 
airplane to a location where the requirements of this AD can be 
accomplished.

    Issued in Renton, Washington, on April 29, 1994.
James V. Devany,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-10777 Filed 5-4-94; 8:45 am]
BILLING CODE 4910-13-U