[Federal Register Volume 63, Number 57 (Wednesday, March 25, 1998)]
[Proposed Rules]
[Pages 14383-14385]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-7676]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-CE-100-AD]
RIN 2120-AA64


Airworthiness Directives; British Aerospace Jetstream Model 3101 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes to adopt a new airworthiness directive 
(AD) that would apply to all British Aerospace (BAe) Jetstream Model 
3101 airplanes equipped with a certain autopilot. The proposed action 
would require modifying the autopilot elevator electric system relays 
by installing two additional relays and associated wiring changes in 
the relay box located under the right hand crew seat. The proposed AD 
is the result of mandatory continuing airworthiness information (MCAI) 
issued by the airworthiness authority for the United Kingdom. The 
actions specified by the proposed AD are intended to prevent failure of 
the autopilot elevator electric system relays for the up and down trim 
interlocks, which, if not corrected, could result in uncommanded trim 
servo operation and possible loss of control of the airplane.

DATES: Comments must be received on or before April 27, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Central Region, Office of the Regional Counsel, 
Attention: Rules Docket No. 97-CE-100-AD, Room 1558, 601 E. 12th 
Street, Kansas City, Missouri 64106. Comments may be inspected at this 
location between 8 a.m. and 4 p.m., Monday through Friday, holidays 
excepted.
    Service information that applies to the proposed AD may be obtained 
from British Aerospace Regional Aircraft, Prestwick International 
Airport, Ayrshire, KA9 2RW, Scotland; telephone (01292) 479888; 
facsimile (01292) 479703. This information also may be examined at the 
Rules Docket at the address above.

FOR FURTHER INFORMATION CONTACT: Mr. S. M. Nagarajan, Aerospace 
Engineer, Small Airplane Directorate, Aircraft Certification Service, 
1201 Walnut, suite 900, Kansas City, Missouri 64106.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the

[[Page 14384]]

proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications should 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 that summarizes 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 No. 97-CE-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, Central Region, Office of the Regional Counsel, Attention: 
Rules Docket No. 97-CE-100-AD, Room 1558, 601 E. 12th Street, Kansas 
City, Missouri 64106.

Discussion

    The Civil Airworthiness Authority (CAA), which is the airworthiness 
authority for the United Kingdom, notified the FAA that an unsafe 
condition may exist on all BAe Jetstream Model 3101 airplanes equipped 
with an autopilot system installed under Jetstream Aircraft Limited 
(JAL) Modifications JM3027, 3243, 3352, or 3483. These modifications 
encompassed the installation of an autopilot system that had pitch-up 
and pitch-down relays with an 800 hour life limit. The CAA reports that 
the cause of the failure of the trip relays is due to the relay 
contacts opening and closing several times when the coil is de-
energized rather than breaking cleanly in one operation. This results 
in premature failure of the relay contacts.
    These conditions, if not corrected, could result in uncommanded 
trim servo operation and possible loss of control of the airplane.

Relevant Service Information

    BAe has issued Jetstream 3100/3200 Series Service Bulletin 22-JK 
2628, Revision 2, dated October 21, 1996, which specifies procedures 
for modifying the autopilot trim relays (which removes the 800 hour 
life cycle restriction on the pitch up and pitch down relays) by 
incorporating Kit No. JK2628, which provides two additional relays in 
the relay box located below the right hand crew seat in the cockpit.
    The CAA classified this service bulletin as mandatory and issued 
British AD No. 006-10-96, undated, in order to assure the continued 
airworthiness of these airplanes in the United Kingdom.

The FAA's Determination

    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 (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 including the service information referenced 
above, and determined that AD action is necessary for products of this 
type design that are certificated for operation in the United States.

Explanation of the Provisions of the Proposed AD

    Since an unsafe condition has been identified that is likely to 
exist or develop in other BAe Jetstream Model 3101 airplanes of the 
same type design that are registered in the United States, and are 
equipped with autopilot systems installed under JAL Modifications 
JM3027, 3243, 3352, or 3483, the FAA is proposing AD action. The 
proposed AD would require modifying the autopilot system by installing 
two additional relays and associated wiring changes in the relay box 
located below the right-hand crew seat in the cockpit. Accomplishment 
of the proposed installation would be in accordance with Jetstream 
Series 3100/3200 Service Bulletin 22-JK 2628, Revision 2: October 21, 
1996.

Proposed Compliance Time

    The compliance time of this AD is presented in calendar time 
instead of hours time-in-service (TIS). The FAA has determined that a 
calendar time compliance is the most desirable method because the 
unsafe condition described by this AD occurs regardless of the hours 
time-in-service. The electrical failure in the relay contacts occurs 
from frequent use whether or not the airplane is actually in flight. 
Therefore, to ensure that the above-referenced condition is corrected 
on all of the affected airplanes within a reasonable period of time 
without inadvertently grounding any airplanes, a compliance schedule 
based upon calendar time instead of hours TIS is proposed.

Cost Impact

    The FAA estimates that 189 airplanes in the U.S. registry would be 
affected by the proposed AD, that it would take approximately 6 
workhours per airplane to accomplish the proposed action, and that the 
average labor rate is approximately $60 an hour. Parts cost 
approximately $430 per airplane. Based on these figures, the total cost 
impact of the proposed AD on U.S. operators is estimated to be $149,310 
or $790 per airplane.

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 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) 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 has been placed 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

[[Page 14385]]

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 a new airworthiness directive 
(AD) to read as follows:

British Aerospace: Docket No. 97-CE-100-AD.

    Applicability: Jetstream Model 3101 airplanes (all serial 
numbers), certificated in any category, that are equipped with 
autopilot systems installed under Jetstream Aircraft Limited (JAL) 
Modifications JM3027, 3243, 3352, or 3483.

    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 
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 within the next 12 calendar months after 
the effective date of this AD, unless already accomplished.
    To prevent failure of the autopilot elevator electric system 
relays for the up and down trim interlocks, which if not corrected, 
could result in uncommanded trim servo operation and possible loss 
of control of the airplane, accomplish the following:
    (a) Modify the autopilot system with Jetstream Aircraft Ltd. 
(JAL) Kit No. JK2628 in accordance with Jetstream 3100/3200 Series 
Service Bulletin No. 22-JK 2628, Revision 2: October 21, 1996, by 
installing two additional relays in the relay box with associated 
wiring changes. This relay box is located under the right-hand crew 
seat in the cockpit.
    (b) 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.
    (c) An alternative method of compliance or adjustment of the 
compliance time that provides an equivalent level of safety may be 
approved by the Manager, Small Airplane Directorate, Aircraft 
Certification Service, 1201 Walnut, suite 900, Kansas City, Missouri 
64106. The request shall be forwarded through an appropriate FAA 
Maintenance Inspector, who may add comments and then send it to the 
Manager, Small Airplane Directorate.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Small Airplane Directorate.

    (d) Questions or technical information related to Jetstream 
3100/3200 Series Service Bulletin No. 22-JK 2628, Revision 2: 
October 21, 1996 should be directed to British Aerospace Regional 
Aircraft, Prestwick International Airport, Ayrshire, KA9 2RW, 
Scotland; telephone (01292) 479888; facsimile (01292) 479703. This 
service information may be examined at the FAA, Central Region, 
Office of the Regional Counsel, Room 1558, 601 E. 12th Street, 
Kansas City, Missouri 64106.

    Note 3: The subject of this AD is addressed in the British AD 
No. 006-10-96, undated.

    Issued in Kansas City, Missouri, on March 17, 1998.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 98-7676 Filed 3-24-98; 8:45 am]
BILLING CODE 4910-13-P