[Federal Register Volume 59, Number 77 (Thursday, April 21, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-8176]


[[Page Unknown]]

[Federal Register: April 21, 1994]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 93-NM-169-AD; Amendment 39-8873; AD 94-08-02]

 

Airworthiness Directives; Jetstream Model ATP Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain Jetstream Model ATP series airplanes, that 
requires modification of the wiring for the electric-powered disconnect 
unit for the elevator control system and a subsequent functional test 
of the elevator control system. This amendment is prompted by an in- 
service report of damaged wire insulation in the electrical power 
circuit for the elevator disconnect unit, which resulted in grounding 
of the circuit and consequent uncommanded operation of the disconnect 
unit. The actions specified by this AD are intended to prevent 
uncommanded operation of the elevator disconnect unit, which would 
result in single elevator operation and, consequently, reduced 
controllability of the airplane.

DATES: Effective May 23, 1994.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of May 23, 1994.

ADDRESSES: The service information referenced in this AD 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 Federal Aviation Administration (FAA), Transport 
Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton, 
Washington; or at the Office of the Federal Register, 800 North Capitol 
Street, NW., suite 700, Washington, DC.

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: A proposal to amend part 39 of the Federal 
Aviation Regulations to include an airworthiness directive (AD) that is 
applicable to certain Jetstream Model ATP series airplanes was 
published in the Federal Register on December 6, 1993 (58 FR 64199). 
That action proposed to require modification of the wiring for the 
electric-powered disconnect unit for the elevator control system and a 
subsequent functional test of the elevator control system.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the single comment received.
    The commenter supports the proposal.
    Since the issuance of the notice, Jetstream Aircraft Limited has 
issued Revision 2 of Service Bulletin ATP-27-49-1023A, dated November 
23, 1993. This revision of the service bulletin is essentially 
identical to Revision 1, which was referenced in the notice, but 
contains corrections of certain minor errors. It also excludes two 
airplanes (Aircraft Constructor's numbers 2046 and 2047) from the 
effectivity listing, since these airplanes are not subject to the 
addressed unsafe condition. The FAA has revised the applicability of 
the final rule to exclude these two airplanes. The FAA has also revised 
paragraph (a) of the final rule to include a reference to Revision 2 of 
the service bulletin as an additional source of appropriate service 
information.
    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes previously 
described. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.
    The FAA estimates that 10 airplanes of U.S. registry will be 
affected by this AD, that it will take approximately 8 work hours per 
airplane to accomplish the required actions, and that the average labor 
rate is $55 per work hour. Required parts will cost approximately $25 
per airplane. Based on these figures, the total cost impact of the AD 
on U.S. operators is estimated to be $4,650, or $465 per airplane.
    The total cost impact figure discussed above is based on 
assumptions that no operator has yet accomplished any of the 
requirements of this AD action, and that no operator would accomplish 
those actions in the future if this AD were not adopted.
    The regulations adopted herein will 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 final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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:

94-08-02 Jetstream Aircraft Limited (Formerly British Aerospace): 
Amendment 39-8873. Docket 93-NM-169-AD.

    Applicability: Model ATP airplanes, Aircraft Constructor's numbers 
2002 through 2045, inclusive; certificated in any category.
    Compliance: Required as indicated, unless accomplished previously.
    To prevent uncommanded operation of the elevator disconnect unit, 
which would result in single elevator operation and consequent reduced 
controllability of the airplane, accomplish the following:
    (a) Within 6 months after the effective date of this AD, modify the 
wiring for the electric-powered disconnect unit for the elevator 
control system (Modification 10234A); and, prior to further flight 
after modification, perform a functional test of the elevator control 
system; in accordance with BAe ATP Service Bulletin ATP-27-49-10234A, 
Revision 1, dated August 14, 1993, or Revision 2, dated November 23, 
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, 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.
    (d) The modification shall be done in accordance with the following 
BAe ATP service bulletins, which contain the following list of 
effective pages: 

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       Service bulletin number and date                    Page No.               Revision level shown on page               Date shown on page         
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ATP-27-49-10234A, Revision 1, August 14, 1993..        1-5, 7, 9, 11, 13, 15  1                                     August 14, 1993                     
                                                            6, 8, 10, 12, 14  (These pages are not used.)           (These pages are not used.)         
ATP-27-49-10234A, Revision 2, November 23, 1993            1-5, 7, 9, 11, 13  2                                     November 23, 1993                   
                                                                6, 8, 10, 12  (These pages are not used.)           (These pages are not used.)         
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    This incorporation by reference was approved by the Director of the 
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. 
Copies may be obtained from Jetstream Aircraft, Inc., P.O. Box 16029, 
Dulles International Airport, Washington, DC 20041-6029. Copies may be 
inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, 
SW., Renton, Washington; or at the Office of the Federal Register, 800 
North Capitol Street, NW., suite 700, Washington, DC.
    (e) This amendment becomes effective on May 23, 1994.

    Issued in Renton, Washington, on March 31, 1994.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-8176 Filed 4-20-94; 8:45 am]
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