[Federal Register Volume 60, Number 31 (Wednesday, February 15, 1995)]
[Proposed Rules]
[Pages 8593-8595]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-3753]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 94-NM-218-AD]


Airworthiness Directives; Jetstream Aircraft Limited Model 4101 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes to revise an existing airworthiness 
directive (AD), applicable to all Jetstream Model 4101 airplanes, that 
currently requires modification of the mounting structure of the 
elevator controls on the rear pressure bulkhead. That proposal was 
prompted by results of a structural analysis which indicate that 
certain structure in the elevator control system may be subject to 
deformation when maximum load is exerted by the pilot(s) in the event 
of a jam in the elevator control cables. This action would limit the 
applicability of the rule. The actions specified by the proposed AD are 
intended to prevent reduced controllability of the airplane due to 
structural deformation in the elevator control system.

DATES: Comments must be received by March 27, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 94-NM-218-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 Jetstream Aircraft, Inc., P.O. Box 16029, Dulles 
International Airport, Washington, DC 20041-6029. This information may 
be examined at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT: William Schroeder, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 
227-2148; 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-218-AD.'' The postcard will be date stamped and 
returned to the commenter. [[Page 8594]] 

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-218-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On June 23, 1994, the FAA issued AD 94-14-07, amendment 39-8959 (59 
FR 35247, July 11, 1994), applicable to all Jetstream Model 4101 
airplanes, to require modification of the mounting structure of the 
elevator controls on the rear pressure bulkhead. That action was 
prompted by the results of a structural analysis which indicate that 
certain structure in the elevator control system may be subject to 
deformation when maximum load is exerted by the pilot(s) in the event 
of a jam in the elevator control cables. The requirements of that AD 
are intended to prevent reduced controllability of the airplane due to 
structural deformation in the elevator control system.
    Since the issuance of that AD, Jetstream has issued Revision 1 
(dated October 3, 1994) to Service Bulletin J41-53-012-41262A, which 
was referenced in AD 94-17-04 as the appropriate source of service 
information. This revision of the service bulletin is essentially the 
same as the originally issued version, insofar as the modification 
procedures described. However, Revision 1 has been revised to specify 
that, if previously installed, a certain modification does not need to 
be reinstalled. Additionally, the effectivity listing in Revision 1 has 
been limited to specify only those Model 4101 airplanes on which the 
modification has not been accomplished. The Civil Aviation Authority 
(CAA), which is the airworthiness authority for the United Kingdom, 
classified Revision 1 as mandatory.
    Since AD 94-14-07 currently is applicable to ``all'' Jetstream 
Model 4101 airplanes, the FAA finds that the applicability of that AD 
must be revised to limit it to only airplanes on which the subject 
modification has not been accomplished. Airplanes that have been 
modified previously are considered to be in compliance with the 
existing AD, and are not subject to the unsafe condition addressed by 
it. In accordance with part 39 of the Federal Aviation Regulations (14 
CFR part 39) and Executive Order 12866, the purpose of AD's is to 
mandate actions to correct unsafe conditions while imposing the least 
necessary burden on the public. The unsafe condition addressed by this 
AD action has been found not to exist with regard to airplanes 
previously modified; therefore, to make the AD applicable to airplanes 
on which it has been determined that the unsafe condition does not 
exist would be contrary to this purpose.
    Additionally, the FAA considers that revising the applicability of 
the existing AD is necessary in order to eliminate any ambiguity 
regarding whether or not airplanes previously modified would be 
required to be modified again. -
    This airplane model is manufactured in the United Kingdom 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. Pursuant 
to this bilateral airworthiness agreement, the CAA has kept the FAA 
informed of the situation described above. The FAA has examined the 
findings of the CAA, 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 revise AD 94-14-07 to limit 
the applicability to airplanes that have not been previously modified 
in accordance with the requirements of the AD. This proposed revision 
would continue to require modification of the mounting structure of the 
elevator controls on the rear pressure bulkhead on airplanes not 
previously modified.
    The FAA estimates that 8 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 17 work 
hours per airplane to accomplish the proposed actions, and that the 
average labor rate is $60 per work hour. Required parts would be 
supplied by the manufacturer at no cost to the operators. Based on 
these figures, the total cost impact of the proposed AD on U.S. 
operators is estimated to be $8,160, or $1,020 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 
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. 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 removing amendment 39-8959 (59 FR 
35247, July 11, 1994), and by adding a new airworthiness directive 
(AD), to read as follows:

Jetstream Aircraft Limited: Docket 94-NM-218-AD. Revises AD 94-14-
07, Amendment 39-8959.

    Applicability: Model 4101 airplanes, as listed in Jetstream 
Service Bulletin J41-53-012-41262A, Revision 1, dated October 3, 
1994, 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 use the authority 
provided in paragraph (b) to request approval from the FAA. This 
approval may address either no action, if the current configuration 
[[Page 8595]] eliminates the unsafe condition; or different actions 
necessary to address the unsafe condition described in this AD. Such 
a request should include an assessment of the effect of the changed 
configuration on the unsafe condition addressed by this AD. In no 
case does the presence of any modification, alteration, or repair 
remove any airplane from the applicability of this AD.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent reduced controllability of the airplane due to 
structural deformation in the elevator control system, accomplish 
the following:
    (a) Within 6 months after August 10, 1994 (the effective date of 
AD 94-14-07, amendment 39-8959), modify the mounting structure of 
the elevator controls on the rear pressure bulkhead, in accordance 
with Jetstream Service Bulletin J41-53-012, dated November 30, 1993, 
or Revision 1, dated October 3, 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 2: 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 
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 February 9, 1995.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 95-3753 Filed 2-14-95; 8:45 am]
BILLING CODE 4910-13-U