[Federal Register Volume 62, Number 5 (Wednesday, January 8, 1997)]
[Proposed Rules]
[Pages 1061-1063]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-363]


      
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 Proposed Rules
                                                 Federal Register
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 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
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 

  Federal Register / Vol. 62, No. 5 / Wednesday, January 8, 1997 / 
Proposed Rules  

[[Page 1061]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-NM-100-AD]
RIN 2120-AA64


Airworthiness Directives; Jetstream Model BAe ATP 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 certain Jetstream Model BAe ATP 
series airplanes. This proposal would require modification of certain 
parts in the elevator flight control system and the propeller pitch 
warning system. This proposal is prompted by a report indicating that 
these parts could interfere with the proper operation of these systems. 
The actions specified by the proposed AD are intended to prevent the 
flight crew from having to engage the standby elevator control system 
in order to regulate the pitch of the airplane; and to prevent 
malfunctioning of the pitch warning system for the propellers; either 
of which could lead to reduced controllability of the airplane.

DATES: Comments must be received by February 18, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 96-NM-100-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) 227-1149.

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 96-NM-100-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. 96-NM-100-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 two 
unrelated unsafe conditions, which could lead to similar consequences, 
may exist on certain Jetstream Model BAe ATP series airplanes. The CAA 
advises that it has received a report indicating that there have been 
occurrences of restriction or interference with movement of the 
elevator flight control system on some of these airplanes. The 
manufacturer conducted a zonal survey of this airplane model to detect 
where movement of these controls could be impeded. That survey revealed 
the following information:
    The flight control system for the elevators, which is located in an 
area under the flight deck, has small clearances between some of its 
components and surrounding structures. This design creates the 
potential for foreign objects to interfere with or restrict movement of 
the stop lever for this system's bellcrank assembly. If movement of 
this lever is impeded, the flight crew must engage the standby control 
system for the elevators, which enables one, but not both elevators to 
be operated. When only one elevator is working, it becomes more 
difficult for the flight crew to control the pitch of the airplane. 
This condition, if not corrected, could lead to reduced controllability 
of the airplane.
    The zonal survey also indicated that there could be interference 
with the controls for the propeller pitch warning system on airplanes 
on which Jetstream Modification 35205A has been installed. (That 
modification is described in Jetstream Service Bulletin ATP-53-19, 
dated January 13, 1993, which contains procedures for installing of two 
access panels in the floor of the flight deck to make it easier for 
maintenance personnel to adjust the microswitches for the powerplant.). 
During normal operation of this system, a green warning light stays on 
when the propellers are in low pitch and the airplane does not exceed 
60 knots Indicated Airspeed (IAS); when that airspeed is exceeded, a 
red warning light comes on and the flight crew knows that the pitch of 
the propellers must be increased. Should a retaining cord on the access 
panel impede operation of the microswitches, the green warning light 
could remain on when the airplane is flying at a speed greater than 60 
knots IAS, and the flight

[[Page 1062]]

crew may not be immediately aware of the need to increase propeller 
pitch. This malfunctioning of the propeller low pitch warning system, 
if not corrected, could lead to the propeller operating at low pitch 
and high airspeed, and consequent reduced controllability of the 
airplane.

Explanation of Relevant Service Information

    Jetstream has issued Service Bulletin ATP-27-78, Revision 1, dated 
January 31, 1996, which describes procedures for modification of the 
stop lever for the bellcrank assembly in the elevator flight control 
system. This modification, which entails shortening the lever and thus 
increasing clearance at its end, is intended to remove potential 
impediments to proper movement of the lever.
    This service bulletin also describes procedures for modification of 
the two access panels to the powerplant microswitches on airplanes that 
have been fitted with Jetstream Modification 35205A. This modification, 
which entails removal of the retaining cords on these panels, is 
intended to remove potential impediments to proper operation of these 
switches and the propeller pitch warning system.
    The CAA classified this service bulletin as mandatory and issued 
British airworthiness directive 003-12-95, dated January 31, 1996, in 
order to assure the continued airworthiness of these airplanes in the 
United Kingdom.

FAA's Conclusions

    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.

Explanation of Requirements of Proposed Rule

    Since unsafe conditions have been identified that are 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 
stop lever for the bellcrank assembly of the elevator flight control 
system. It also would require that retaining cords on the access panels 
to the powerplant microswitches be removed from airplanes on which 
Jetstream Modification 35205A has been installed previously.
    These actions would be required to be accomplished in accordance 
with the service bulletin described previously.

Cost Impact

    The FAA estimates that 10 Jetstream Model BAe ATP series airplanes 
of U.S. registry would be affected by this proposed AD.
    It would take approximately 7 work hours per airplane to accomplish 
the proposed modification of the stop lever for the bellcrank assembly 
of the elevator flight control system, at an average labor rate of $60 
per work hour. Based on these figures, the cost impact of the proposed 
modification of this lever on U.S. operators is estimated to be $4,200, 
or $420 per airplane.
    It would take approximately 1 work hour per airplane to accomplish 
the proposed removal of the retaining cords on airplanes that have been 
fitted with Jetstream Modification 35205A. The average labor rate is 
$60 per work hour. Based on these figures, the cost impact of this 
proposed removal on U.S. operators of airplanes fitted with Jetstream 
Modification 35205A is estimated to be $600, or $60 per airplane.
    The cost impact figures discussed above are 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.

Regulatory Impact

    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. 106(g), 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:
Jetstream Aircraft Limited (Formerly British Aerospace Commercial 
Aircraft Limited): Docket 96-NM-100-AD.

    Applicability: Model BAe ATP series airplanes as listed in 
Jetstream Service Bulletin ATP-27-78, Revision 1, dated January 31, 
1996; certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
otherwise 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 
alternative method of compliance in accordance with paragraph (c) 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 the flight crew from having to engage the standby 
elevator control system in order to regulate the pitch of the 
airplane, and to prevent malfunctioning of the pitch warning system 
for the propellers, either of which could lead to reduced 
controllability of the airplane, accomplish the following:
    (a) For airplanes on which Jetstream Modification 35205A has 
been installed: Within 3 months after the effective date of this AD, 
remove the retaining cords on the access panels to the powerplant 
microswitches, in accordance with Part 2 of Jetstream Service 
Bulletin ATP-27-78, Revision 1, dated January 31, 1996.


[[Page 1063]]


    Note 2: Jetstream Modification 35202A is described in Jetstream 
Service Bulletin ATP-53-19, dated January 13, 1993.

    (b) For all airplanes: Within 18 months after the effective date 
of this AD, modify the stop lever for the bellcrank assembly of the 
elevator flight control system, in accordance with Part 1 of 
Jetstream Service Bulletin ATP-27-78, Revision 1, dated January 31, 
1996.
    (c) 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 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Standardization Branch, ANM-113.

    (d) 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 2, 1997.
S.R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-363 Filed 1-7-97; 8:45 am]
BILLING CODE 4910-13-U