[Federal Register Volume 62, Number 44 (Thursday, March 6, 1997)]
[Proposed Rules]
[Pages 10240-10242]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-5491]



[[Page 10240]]

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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 86-CE-23-AD]
RIN 2120-AA64


Airworthiness Directives; Pilatus Britten-Norman Ltd. (formerly 
Britten-Norman) BN2A MK. 111 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes to revise AD 86-07-02, which currently 
requires repetitively inspecting the junction of the torque link lug 
and upper case of the main landing gear (MLG) torque link assemblies 
for cracks on Pilatus Britten-Norman Ltd. (Pilatus Britten-Norman) BN-
2A, BN-2B, BN-2T, and BN2A MK. 111 series airplanes, and replacing any 
part found cracked with a like part. The proposed AD would remove from 
the applicability the BN-2A, BN-2B, and BN-2T series airplanes, and 
would retain the repetitive inspection and replacement (if necessary) 
requirements of AD 86-07-02 for the BN2A MK. 111 series airplanes. The 
proposed AD results from the Federal Aviation Administration's 
determination that additional AD action needs to be taken on the BN-2A, 
BN-2B, and BN-2T series airplanes. This additional action will be 
addressed in a separate AD. The actions specified by the proposed AD 
are intended to prevent failure of the main landing gear caused by 
cracks in the torque link area, which could lead to loss of control of 
the airplane during landing operations.

DATES: Comments must be received on or before May 12, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Central Region, Office of the Assistant Chief 
Counsel, Attention: Rules Docket No. 86-CE-23-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 Pilatus Britten-Norman Limited, Bembridge, Isle of Wight, United 
Kingdom PO35 5PR; telephone 44-1983 872511; facsimile 44-1983 873246. 
This information also may be examined at the Rules Docket at the 
address above.

FOR FURTHER INFORMATION CONTACT: Mr. Tom Rodriguez, Program Officer, 
Brussels Aircraft Certification Division, FAA, Europe, Africa, and 
Middle East Office, c/o American Embassy, B-1000 Brussels, Belgium; 
telephone (32 2) 508.2717; facsimile (32 2) 230.6899; or Mr. S.M. 
Nagarajan, Project Officer, Small Airplane Directorate, Airplane 
Certification Service, FAA, 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, 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. 86-CE-23-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRM's

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, Central Region, Office of the Assistant Chief Counsel, 
Attention: Rules Docket No. 86-CE-23-AD, Room 1558, 601 E. 12th Street, 
Kansas City, Missouri 64106.

Discussion

    The FAA has determined that reliance on critical repetitive 
inspections on aging commuter-class airplanes carries an unnecessary 
safety risk when a design change exists that could eliminate or, in 
certain instances, reduce the number of those critical inspections. In 
determining what inspections are critical, the FAA considers (1) the 
safety consequences if the known problem is not detected during the 
inspection; (2) the probability of the problem not being detected 
during the inspection; (3) whether the inspection area is difficult to 
access; and (4) the possibility of damage to an adjacent structure as a 
result of the problem.
    These factors have led the FAA to establish an aging commuter-class 
aircraft policy that requires incorporating a known design change when 
it could replace a critical repetitive inspection. With this policy in 
mind, the FAA conducted a review of existing AD's that apply to Pilatus 
Britten-Norman BN-2A, BN-2B, BN-2T, and BN2A MK. 111 series airplanes. 
Assisting the FAA in this review were (1) Pilatus Britten-Norman; (2) 
the Regional Airlines Association (RAA); (3) the Civil Aviation 
Authority of the United Kingdom; and (4) several operators of the 
affected airplanes.
    From this review, the FAA has identified AD 86-07-02, Amendment39-
5382, as one which falls under the FAA's aging aircraft policy. AD 86-
07-02 currently requires repetitively inspecting the junction of the 
torque link lug and upper case of the main landing gear (MLG) torque 
link assemblies for cracks on Pilatus Britten-Norman BN-2A, BN-2B, BN-
2T, and BN2A MK. 111 series airplanes, and replacing any cracked part.
    Pilatus Britten-Norman has developed a modification that, when 
incorporated, would eliminate the need for the repetitive inspection 
requirement of AD 86-07-02 for the Pilatus Britten-Norman BN-2A, BN-2B, 
and BN-2T series airplanes. The requirements of AD 86-07-02 should 
still apply for the Pilatus Britten-Norman BN2A MK. 111 series 
airplanes.

Applicable Service Information

    Fairey Hydraulics Limited has issued Service Bulletin (SB) 32-7, 
Issue 3, dated January 30, 1990, and Fairey Hydraulics Limited SB 32-
10, Issue 2, dated November 10, 1992. These SB's include procedures for 
inspecting the junction of the torque link lug and upper case of the 
MLG torque link assemblies on Pilatus Britten-Norman BN2A MK. 111 
series airplanes. Pilatus Britten-Norman SB BN-2/SB. 173, Issue 3, 
dated November 16, 1990, references Fairey Hydraulic Limited SB 32-7; 
and Pilatus Britten-Norman SB BN-2/SB.209, Issue 1, datedNovember 30, 
1992, references Fairey Hydraulic Limited SB 32-10.

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The FAA's Determination

    The FAA has examined all available information related to this 
subject matter and has determined that:
     AD 86-07-02 should be revised to remove the BN-2A, BN-2B, 
and BN-2T series airplanes from the applicability of the AD (the BN2A 
MK. 111 series airplanes should still apply); and
     separate AD action should be taken for the Pilatus 
Britten-NormanBN-2A, BN-2B, and BN-2T series airplanes to require a 
modification to the main landing gear torque link assembly.

Explanation of the Provisions of the Proposed AD

    Since an unsafe condition has been identified that is likely to 
exist or develop in other Pilatus Britten-Norman BN2A MK. 111 series 
airplanes of the same type design, the proposed AD would revise AD 86-
07-02 by removing the BN-2A, BN-2B, and BN-2T series airplanes from the 
applicability of that AD. The requirement of repetitively inspecting 
the junction of the torque link lug and upper case of the MLG torque 
link assemblies would be retained for the BN2A MK. 111 series 
airplanes. The FAA will propose separate AD action for the BN-2A and 
BN-2T series airplanes to require a modification that, when 
incorporated, would eliminate the repetitive inspection requirement 
currently required by AD 86-07-02. Accomplishment of the proposed 
inspections and would be accomplished in accordance with the previously 
referenced service bulletins.

Cost Impact

    The FAA estimates that nine airplanes in the U.S. registry would be 
affected by the proposed AD, that it would take approximately one 
workhour per airplane to accomplish the proposed initial inspection, 
and that the average labor rate is approximately $60 an hour. Based on 
these figures, the total cost impact of the proposed AD on U.S. 
operators is estimated to be $540 or $60 per airplane. This figure only 
takes into account the cost of the proposed initial inspection and does 
not take into account the cost of the proposed repetitive inspections. 
The FAA has no way of determining the number of repetitive inspections 
each of the owners/operators would incur over the life of the affected 
airplanes.
    In addition, the proposed inspections are currently required on the 
nine affected airplanes. The proposed AD would not require any 
additional actions over that already required by AD 86-07-02.

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 removing Airworthiness Directive 
(AD) 86-07-02, Amendment 39-5382, and by adding a new AD to read as 
follows:

Pilatus Britten-Norman LTD.: Docket No. 86-CE-23-AD. Revises AD 86-
07-02, Amendment 39-5382.

    Applicability: Models MK. 111, BN2A MK. 111-2, and BN2A MK. 111-
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 (f) 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 prior to further flight after the effective 
date of this AD (see Note 2) or within 100 hours time-in-service 
(TIS) after the last inspection accomplished in accordance with AD 
86-07-02, whichever occurs later, and thereafter at intervals not to 
exceed100 hours TIS.

    Note 2: The ``prior to further flight after the effective date 
of this AD'' compliance time was the original initial compliance 
time of AD 86-07-02, and is being retained to provide credit and 
continuity for already-accomplished and future inspections.
    To prevent failure of the main landing gear caused by cracks in 
the torque link assembly area, which could lead to loss of control 
of the airplane during landing operations, accomplish the following:
    (a) Inspect the junction of the torque link lug and upper case 
for cracks (using a 10-power magnifying glass or by dye penetrant 
methods) in accordance with Fairey Hydraulics Limited Service 
Bulletin (SB) 32-7, Issue 3, dated January 30, 1990, or Fairey 
Hydraulics SB 32-10, Issue 2, dated November 10, 1992, as 
applicable. Pilatus Britten-Norman SB BN-2/SB. 173, Issue 3, dated 
November 16, 1990, references Fairey Hydraulic Limited SB 32-7; and 
Pilatus Britten-Norman SB BN-2/SB.209, Issue 1, dated November 30, 
1992, references Fairey Hydraulic Limited SB 32-10.
    (b) If cracked parts are found during any of the inspections 
required by this AD, prior to further flight, replace the cracked 
parts with airworthy parts in accordance with the applicable 
maintenance manual.
    (c) If the landing gear is replaced, only equal pairs of the 
same manufacturer are approved as replacement parts. Mixing of 
different manufacturer landing gears is not authorized.
    (d) The intervals between the repetitive inspections required by 
this AD may be adjusted up to 10 percent of the specified interval 
to allow accomplishing these actions along with other scheduled 
maintenance on the airplane.
    (e) 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 inspection requirements of this AD can be accomplished.
    (f) 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, Brussels Aircraft 
Certification Division, Europe, Africa, Middle East office, FAA, c/o 
American Embassy, 1000 Brussels, Belgium. The request should be 
forwarded through an appropriate FAA Maintenance Inspector, who may 
add comments and then send it to the Manager, Brussels Aircraft 
Certification Division. Alternative methods of

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compliance approved for AD 86-07-02 are considered approved as 
alternative methods of compliance for this AD.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Brussels Aircraft Certification Division.

    (g) All persons affected by this directive may obtain copies of 
the documents referred to herein upon request to Fairey Hydraulics 
Limited, Claverham, Bristol, England; or Pilatus Britten-Norman 
Limited, Bembridge, Isle of Wight, United Kingdom PO35 5PR, as 
applicable; or may examine these documents at the FAA, Central 
Region, Office of the Assistant Chief Counsel, Room 1558, 601 E. 
12th Street, Kansas City, Missouri 64106.
    (h) This amendment revises AD 86-07-02, Amendment 39-5382.

    Issued in Kansas City, Missouri, on February 25, 1997.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 97-5491 Filed 3-5-97; 8:45 am]
BILLING CODE 4910-13-U