[Federal Register Volume 59, Number 50 (Tuesday, March 15, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-5934]


[[Page Unknown]]

[Federal Register: March 15, 1994]


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


DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 94-NM-15-AD]

 

Airworthiness Directives; Jetstream Aircraft Limited Model 4101 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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

SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to all Jetstream Model 4101 
airplanes. This proposal would require modification of the mounting 
structure of the elevator controls on the rear pressure bulkhead. This 
proposal is 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 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 April 25, 1994.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 94-NM-15-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 Jetstream Aircraft, Incorporated, 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 changed 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-15-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-15-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The Civil Aviation Authority (CAA), which is the airworthiness 
authority for the United Kingdom, recently notified the FAA that an 
unsafe condition may exist on all Jetstream Model 4101 airplanes. The 
CAA advises that the results of a structural analysis revealed that the 
mounting structure on the elevator controls 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 condition, if not 
corrected, could result in reduced controllability of the airplane due 
to structural deformation in the elevator control system. -
    Jetstream has issued Service Bulletin J41-53-012, dated November 
30, 1993, that describes procedures for modification of the mounting 
structure of the elevator controls on the rear pressure bulkhead. This 
modification entails installing thicker support brackets and additional 
stiffening to the mounting structure of the upper and lower pulley 
installations of the elevator and rudder cables aft of the rear 
pressure bulkhead. The CAA classified this service bulletin as 
mandatory in order to assure the continued airworthiness of these 
airplanes in the United Kingdom. -
    This airplane model is manufactured in the United Kingdom 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 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 require modification of the 
mounting structure of the elevator control components on the rear 
pressure bulkhead. The actions would be required to be accomplished in 
accordance with the service bulletin described previously. -
    The FAA estimates that 8 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 16.5 
work hours per airplane to accomplish the proposed actions, and that 
the average labor rate is $55 per work hour. Required parts would be 
provided at no cost to the operator. Based on these figures, the total 
cost impact of the proposed AD on U.S. operators is estimated to be 
$7,260, or $907.50 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:

Jetstream Aircraft Limited: Docket 94-NM-15-AD.

    -Applicability: All Model 4101 airplanes, certificated in any 
category. -
    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 the effective date of this AD, 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. -
    (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. 
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 March 9, 1994.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-5934 Filed 3-14-94; 8:45 am]
BILLING CODE 4910-13-U