[Federal Register Volume 63, Number 177 (Monday, September 14, 1998)]
[Proposed Rules]
[Pages 49050-49052]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-24522]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-CE-122-AD]
RIN 2120-AA64


Airworthiness Directives; British Aerospace (Operations) Limited 
Model B.121 Series 1, 2, and 3 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 (Operations) Limited 
(British Aerospace) Model B.121 Series 1, 2, and 3 airplanes. The 
proposed AD would require repetitively inspecting (using visual 
methods) the internal and external surfaces of the brake torque tube 
assemblies in the cockpit area for cracks. The proposed AD would also 
require obtaining and incorporating repair procedures for any brake 
torque tube assembly found cracked. 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 detect and correct cracks in the 
brake torque tube assemblies, which could result in reduced brake 
efficiency with possible reduced and/or loss of airplane control.

DATES: Comments must be received on or before October 15, 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-122-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 (Operations) Limited, 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. Roger Chudy, Aerospace Engineer, 
Small Airplane Directorate, Aircraft Certification Service, 1201 
Walnut, suite 900, Kansas City, Missouri 64106; telephone: (816) 426-
6932; facsimile: (816) 426-2169.

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 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,

[[Page 49051]]

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-122-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-122-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, recently notified the FAA that an 
unsafe condition may exist on all British Aerospace Model B.121 Series 
1, 2, and 3 airplanes. The CAA reports that cracks have been found in 
the brake torque tube assemblies on airplanes that have similar design 
assemblies to that of these Model B.121 Series 1, 2, and 3 airplanes.
    This condition, if not detected and corrected, could result in 
reduced brake efficiency with possible reduced and/or loss of airplane 
control.

Relevant Service Information

    British Aerospace (Operations) Limited has issued PUP Service 
Bulletin No. B121/103, ORIGINAL ISSUE: October 26, 1995, which 
specifies procedures for visually inspecting the internal and external 
surfaces of the brake torque tube assemblies in the cockpit area for 
cracks. This service bulletin also specifies obtaining repair 
procedures from the manufacturer if any brake torque tube assembly is 
found cracked.
    The CAA classified this service bulletin as mandatory and issued 
British AD 003-10-95, not dated, 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 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, 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 British Aerospace Model B.121 Series 1, 2, 
and 3 airplanes of the same type design registered in the United 
States, the FAA is proposing AD action. The proposed AD would require 
repetitively inspecting (using visual methods) the internal and 
external surfaces of the brake torque tube assemblies in the cockpit 
area for cracks. The proposed AD would also require obtaining and 
incorporating repair procedures for any brake torque tube assembly 
found cracked. Accomplishment of the proposed inspection would be in 
accordance with Jetstream PUP Service Bulletin No. B121/103, ORIGINAL 
ISSUE: October 26, 1995. Accomplishment of the proposed repair, if 
necessary, would be required in accordance with procedures obtained 
from the manufacturer through the FAA, Small Airplane Directorate.

Cost Impact

    The FAA estimates that 2 airplanes in the U.S. registry would be 
affected by the proposed inspection, that it would take approximately 5 
workhours per airplane to accomplish the proposed inspection, and that 
the average labor rate is approximately $60 an hour. Based on these 
figures, the total cost impact of the proposed inspection on U.S. 
operators is estimated to be $600, or $300 per airplane. These figures 
only take into account the costs of the initial inspection and do not 
take into account the costs for any repetitive inspections or the costs 
associated with repairing or replacing any cracked torque tube 
assemblies found during the proposed inspection. The FAA has no way of 
determining how many torque tube assemblies would be found cracked or 
how many repetitive inspections each owner/operator would incur over 
the life of the affected airplanes.

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 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 (Operations) Limited: Docket No. 97-CE-122-AD.

    Applicability: Model B.121 Series 1, 2, and 3 airplanes, all 
serial numbers, 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 request approval for an 
alternative method of compliance in accordance with paragraph (d) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or

[[Page 49052]]

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 in the body of this AD, unless 
already accomplished.
    To detect and correct cracks in the brake torque tube 
assemblies, which could result in reduced brake efficiency with 
possible reduced and/or loss of airplane control, accomplish the 
following:
    (a) Upon accumulating 3,300 hours time-in-service (TIS) on each 
brake torque tube assembly or within the next 100 hours TIS after 
the effective date of this AD, whichever occurs later, and 
thereafter at intervals not to exceed 600 hours TIS, visually 
inspect each brake torque tube assembly for cracks. Accomplish this 
inspection in accordance with the ACCOMPLISHMENT INSTRUCTIONS 
section of Jetstream PUP Service Bulletin No. B121/103, ORIGINAL 
ISSUE: October 26, 1995.
    (b) If a crack(s) is found during any inspection required by 
paragraphs (a) or (b)(2) of this AD, prior to further flight, 
accomplish the following:
    (1) Obtain repair instructions from the manufacturer through the 
FAA, Small Airplane Directorate, at the address specified in 
paragraph (d) of this AD; and
    (2) Incorporate these repair instructions, and continue to 
reinspect at intervals not to exceed 600 hours TIS.
    (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.
    (d) An alternative method of compliance or adjustment of the 
initial or repetitive compliance times 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.

    (e) Questions or technical information related to Jetstream 
Aircraft Ltd. PUP Service Bulletin No. B121/103, ORIGINAL ISSUE: 
October 26, 1995, should be directed to British Aerospace 
(Operations) Limited, 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 British AD 003-
10-95, not dated.

    Issued in Kansas City, Missouri, on September 4, 1998.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 98-24522 Filed 9-11-98; 8:45 am]
BILLING CODE 4910-13-U