[Federal Register Volume 65, Number 15 (Monday, January 24, 2000)]
[Proposed Rules]
[Pages 3617-3619]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-1598]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-360-AD]
RIN 2120-AA64


Airworthiness Directives; Israel Aircraft Industries, Ltd., Model 
1125 Westwind Astra and Astra SPX Series 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 all Israel Aircraft Industries, 
Ltd., Model 1125 Westwind Astra and Astra SPX series airplanes. This 
proposal would require replacement of the existing pneumatic de-icing 
boot pressure indicator switch with a newly designed switch. This 
proposal is prompted by an occurrence on a similar airplane model in 
which the pneumatic de-icing boot indication light may have provided 
the flightcrew with misleading information as to the proper functioning 
of the de-icing boots. The actions specified by the proposed AD are 
intended to prevent ice accumulation on the airplane leading edges, 
which could result in reduced controllability of the airplane.

DATES:  Comments must be received by February 23, 2000.

ADDRESSES:  Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 99-NM-360-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.
    Information concerning this proposal 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

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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-360-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-360-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On December 26, 1989, a British Aerospace Jetstream Model BA-3101 
series airplane impacted the ground approximately 400 feet short of the 
runway while executing an instrument landing system (ILS) approach. The 
accident occurred at the Tri-Cities Airport, Pasco, Washington. The 
National Transportation Safety Board (NTSB) determined that the 
probable cause of the accident was the flightcrew's decision to 
continue an unstabilized ILS approach that led to a stall, most likely 
of the horizontal stabilizer, and loss of control at low altitude. 
Contributing to the stall and loss of control was the accumulation of 
ice on the leading edge of the wing and the horizontal stabilizer, 
which degraded the aerodynamic performance of the airplane.
    One result of the NTSB investigation was the determination that a 
flight deck wing de-icing light illuminated at a lower pressure than 
the pressure required to fully inflate the de-icing boots.
    Based on an NTSB Safety Recommendation, the FAA reviewed the 
pneumatic de-icing boot system designs for airplanes operated under 
parts 121 and 135 of the Federal Aviation Regulations to ensure that 
the pneumatic pressure threshold at which each de-icing boot indication 
light is designed to illuminate is sufficient pressure for effective 
operation of the pneumatic de-icing boots. The FAA has determined that 
the pneumatic de-icing boot pressure indicator switch located on the 
flight deck of Model 1125 Westwind Astra and Astra SPX series airplanes 
may allow the flight deck indication light to illuminate at a lower 
pressure [13 pounds per square inch gage (psig)] than the pressure 
required to fully inflate the de-icing boots (15 psig). This condition, 
if not corrected, could result in ice accumulation on the airplane 
leading edges, which could result in reduced controllability of the 
airplane.

U.S. Type Certification of the Airplane

    This airplane model is manufactured in Israel and is type 
certificated for operation in the United States under the provisions of 
section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and 
the applicable bilateral airworthiness agreement. The FAA has 
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 that the existing 
pneumatic de-icing boot pressure indicator switch be replaced with a 
switch that activates the indicator light at 15 psig. The action would 
be required to be accomplished in accordance with a method approved by 
the FAA.

Cost Impact

    The FAA estimates that 59 airplanes of U.S. registry would be 
affected by this proposed AD. Since the manufacturer has not yet 
developed a specific modification commensurate with the requirements of 
this proposal, the FAA is unable at this time to provide specific 
information as to the number of work hours or cost of parts that would 
be required to accomplish the proposed modification. As indicated 
earlier in this preamble, the FAA specifically invites the submission 
of comments and other data regarding the economic aspect of this 
proposal.

Regulatory Impact

    The regulations proposed herein would not have a substantial direct 
effect 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, it 
is determined that this proposal would not have federalism implications 
under Executive Order 13132.
    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:

Israel Aircraft Industries, LTD.: Docket 99-NM-360-AD.

    Applicability: All Model 1125 Westwind Astra and Astra SPX 
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

[[Page 3619]]

alternative method of compliance in accordance with paragraph (b) 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 ice accumulation on the airplane leading edges, which 
could result in reduced controllability of the airplane, accomplish 
the following:

Modification

    (a) Within 1 year after the effective date of this AD, replace 
the pneumatic de-icing boot pressure indicator switch with a switch 
that activates the flight deck indicator light at 15 pounds per 
square inch gage, in accordance with a method approved by the 
Manager, International Branch, ANM-116, FAA, Transport Airplane 
Directorate.

Alternative Methods of Compliance

    (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, International Branch, ANM-116. 
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

    (c) Special flight permits may be issued in accordance with 
sections 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.

Issued in Renton, Washington, on January 18, 2000.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-1598 Filed 1-21-00; 8:45 am]
BILLING CODE 4910-13-U