[Federal Register Volume 67, Number 163 (Thursday, August 22, 2002)]
[Proposed Rules]
[Pages 54384-54387]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-21356]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-CE-21-AD]
RIN 2120-AA64


Airworthiness Directives; Pilatus Britten-Norman Limited BN-2, 
BN-2A, BN-2B, BN-2T, and BN2A MK. III Series 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 Pilatus Britten-Norman Limited (Pilatus 
Britten-Norman) BN-2, BN-2A, BN-2B, BN-2T, BN2A MK. III series 
airplanes. This proposed AD would require you to repetitively inspect 
the bottom corner of the engine mount bracket for cracks and replace 
any cracked bracket with a new one. This proposed AD is the result of 
mandatory continuing airworthiness information (MCAI) issued by the 
airworthiness authority for the United Kingdom. The actions specified 
by this proposed AD are intended to detect and correct cracks in the 
engine mount bracket. Such a condition could cause the engine mount 
assembly to fail, which could result in the engine separating from the 
airplane and lead to loss of control of the airplane.

DATES: The Federal Aviation Administration (FAA) must receive any 
comments on this proposed rule on or before September 27, 2002.

ADDRESSES: Submit comments to FAA, Central Region, Office of the 
Regional Counsel, Attention: Rules Docket No. 2002-CE-21-AD, 901 
Locust, Room 506, Kansas City, Missouri 64106. You may view any 
comments at this location between 8 a.m. and 4 p.m., Monday through 
Friday, except Federal holidays. You may also send comments 
electronically to the following address: [email protected]. 
Comments sent electronically must contain ``Docket No. 2002-CE-21-AD'' 
in the subject line. If you send comments electronically as attached 
electronic files, the files must be formatted in Microsoft Word 97 for 
Windows or ASCII text.
    You may get service information that applies to this proposed AD 
from B-N Group Limited, Bembridge, Isle of Wight, United Kingdom PO35 
5PR; telephone: +44 (0) 1983 872511; facsimile: +44 (0) 1983 873246. 
You may also view this information at the Rules Docket at the address 
above.

FOR FURTHER INFORMATION CONTACT: Doug Rudolph, Aerospace Engineer, FAA, 
Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 
64106; telephone: (816) 329-4059; facsimile: (816) 329-4090.

SUPPLEMENTARY INFORMATION:

Comments Invited

How Do I Comment on This Proposed AD?

    The FAA invites comments on this proposed rule. You may submit 
whatever written data, views, or arguments you choose. You need to 
include the rule's docket number and submit your comments to the 
address specified under the caption ADDRESSES. We will consider all 
comments received on or before the closing date. We may amend this 
proposed rule in light of comments received. Factual information that 
supports your ideas and suggestions is extremely helpful in evaluating 
the effectiveness of this proposed AD action and determining whether we 
need to take additional rulemaking action.

Are There Any Specific Portions of This Proposed AD I Should Pay 
Attention To?

    The FAA specifically invites comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed rule that 
might suggest a need to modify the rule. You may view all comments we 
receive before and after the closing date of the rule in the Rules 
Docket. We will file a report in the Rules Docket that

[[Page 54385]]

summarizes each contact we have with the public that concerns the 
substantive parts of this proposed AD.

How Can I Be Sure FAA Receives My Comment?

    If you want FAA to acknowledge the receipt of your mailed comments, 
you must include a self-addressed, stamped postcard. On the postcard, 
write ``Comments to Docket No. 2002-CE-21-AD.'' We will date stamp and 
mail the postcard back to you.

Discussion

What Events Have Caused This Proposed AD?

    The Civil Aviation Authority (CAA), which is the airworthiness 
authority for the United Kingdom, recently notified FAA that an unsafe 
condition may exist on all Pilatus Britten-Norman BN-2, BN-2A, BN-2B, 
BN-2T, and BN2A MK. III series airplanes. The CAA reports two 
occurrences of extensive cracks being found on the bottom corner of the 
engine mount bracket between the attachment flange and the main 
bracket. The cracks were found during regular scheduled maintenance.
    The manufacturer has determined that this condition is a result of 
the reinforcing doubler being too close to the flange.

What Are the Consequences if the Condition Is Not Corrected?

    This condition, if not detected and corrected, could result in 
failure of the engine mount. Such failure could result in the engine 
separating from the airplane and lead to loss of control of the 
airplane.

Is There Service Information That Applies to This Subject?

    Pilatus Britten-Norman has issued Service Bulletin SB 275, Issue 1, 
dated November 30, 2001.

What Are the Provisions of This Service Information?

    The service bulletin includes procedures for inspecting the engine 
mount bracket for cracks and specifies replacing any cracked bracket.

What Action Did the CAA Take?

    The CAA classified this service bulletin as mandatory and issued 
CAA AD Number 005-11-2001, not dated, in order to ensure the continued 
airworthiness of these airplanes in the United Kingdom.

Was This in Accordance With the Bilateral Airworthiness Agreement?

    These airplane models are manufactured in the United Kingdom and 
are 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 FAA informed of the situation described above.

Are There Differences Between This Proposed AD, the Service 
Information, and the CAA AD?

    The CAA AD and the service information allows continued flight if 
cracks are found in the engine mount bracket that do not exceed certain 
limits. The applicable service bulletin specifies replacement of the 
engine mount bracket only if cracks are found exceeding this limit, as 
does CAA AD 005-11-2001. This proposed AD, if adopted, would not allow 
continued flight if any crack is found. FAA policy is to disallow 
airplane operation when known cracks exist in primary structure, unless 
the ability to sustain ultimate load with these cracks is proven. The 
engine mount bracket is considered primary structure, and the FAA has 
not received any analysis to prove that ultimate load can be sustained 
with cracks in this area.

Is There a Modification I Can Incorporate Instead of Repetitively 
Inspecting the Engine Mount Brackets?

    The FAA has determined that long-term continued operational safety 
would be better assured by design changes that remove the source of the 
problem rather than by performing repetitive inspections. With this in 
mind, we will continue to work with Pilatus Britten-Norman in 
collecting information to determine whether a future design change may 
be necessary.

The FAA's Determination and an Explanation of the Provisions of 
this Proposed AD

What Has FAA Decided?

    The FAA has examined the findings of the CAA; reviewed all 
available information, including the service information referenced 
above; and determined that:

--the unsafe condition referenced in this document exists or could 
develop on other Pilatus Britten-Norman BN-2, BN-2A, BN-2B, BN-2T, and 
BN2A MK. III series airplanes of the same type design that are on the 
U.S. registry;
--the actions specified in the previously-referenced service 
information should be accomplished on the affected airplanes; and
--AD action should be taken in order to correct this unsafe condition.

What Would This Proposed AD Require?

    This proposed AD would require you to repetitively inspect the 
bottom corner of the engine mount bracket for cracks, replace any 
cracked bracket, return the removed bracket(s) to Pilatus Britten-
Norman, and report the return to FAA.

Cost Impact

How Many Airplanes Would This Proposed AD Impact?

    We estimate that this proposed AD affects 126 airplanes in the U.S. 
registry.

What Would Be the Cost Impact of This Proposed AD on Owners/Operators 
of the Affected Airplanes?

    We estimate the following costs to accomplish the proposed 
inspection for BN-2, BN-2A, and BN-2B, and BN2A MK. III series 
airplanes:

------------------------------------------------------------------------
                                                              Total cost
                  Labor cost                     Parts cost      per
                                                               airplane
------------------------------------------------------------------------
4 workhours x $60 per hour = $240.............          $10         $250
------------------------------------------------------------------------

    We estimate the following costs to accomplish the proposed 
inspection for BN-2T series airplanes:

[[Page 54386]]



------------------------------------------------------------------------
                                                              Total cost
                  Labor cost                     Parts cost      per
                                                               airplane
------------------------------------------------------------------------
8 workhours x $60 per hour = $480.............          $10         $490
------------------------------------------------------------------------

    We estimate the following costs to accomplish any necessary 
replacements for BN-2, BN-2A, BN-2B, and BN-2T series airplanes that 
would be required based on the results of the proposed inspection. We 
have no way of determining the number of airplanes that may need such 
replacement:

------------------------------------------------------------------------
                                    Parts cost per      Total cost per
           Labor cost                   bracket       bracket per engine
------------------------------------------------------------------------
48 workhours x $60 per hour =     $1,295 (2 brackets  $2,880 + $1,295 =
 $2,880 per engine (2 engines      per engine).        $4,175
 per airplane).
------------------------------------------------------------------------

    We estimate the following costs to accomplish any necessary 
replacements for BN2A MK. III series airplanes that would be required 
based on the results of the proposed inspection. We have no way of 
determining the number of airplanes that may need such replacement:

------------------------------------------------------------------------
                                      Parts cost  Total cost per bracket
             Labor cost              per bracket        per engine
------------------------------------------------------------------------
48 workhours x $60 per hour =               $714  $2,880 + $714 = $3.594
 $2,880 per engine (2 engines per
 airplane).
------------------------------------------------------------------------

What Would Be the Compliance Time of This Proposed AD?

    The compliance time of this proposed AD is ``within the next 500 
hours time-in-service (TIS) or within the next 24 calendar months after 
the effective date of this AD, whichever occurs first.''

Why Is the Compliance Time of This Proposed AD Presented in Both Hours 
TIS and Calendar Time?

    We have established the compliance time of this proposed AD in both 
hours TIS and calendar time. The unsafe condition is dependent upon 
repetitive airplane operation. However, the recommended maintenance 
program specifies other actions in this area at intervals not to exceed 
2 years. Therefore, the compliance time will ensure that high-time 
airplanes are inspected within a certain amount of hours TIS and the 
lower time airplanes would be inspected at the next maintenance event 
in the affected area. We have determined that this compliance time:

--Will ensure that the unsafe condition is addressed in a timely manner 
on all affected airplanes; and
--Will not inadvertently ground any of the affected airplanes.

Regulatory Impact

Would This Proposed AD Impact Various Entities?

    The regulations proposed herein would not have a substantial direct 
effect 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, it 
is determined that this proposed rule would not have federalism 
implications under Executive Order 13132.

Would This Proposed AD Involve a Significant Rule or Regulatory Action?

    For the reasons discussed above, I certify that this proposed 
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, under 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. FAA amends Sec. 39.13 by adding a new airworthiness directive 
(AD) to read as follows:

Pilatus Britten-Norman Limited: Docket No. 2002-CE-21-AD.

    (a) What airplanes are affected by this AD? This AD affects the 
following airplane models, all serial numbers, that are certificated 
in any category:

Models

BN-2, BN-2A, BN-2A-2, BN-2A-3, BN-2A-6, BN-2A-8, BN-2A-9, BN-2A-20, 
BN-2A-21, BN-2A-26, BN-2A-27, BN-2B-20, BN-2B-21, BN-2B-26, BN-2B-
27, BN-2T, BN-2T-4R, BN2A MK. III, BN2A MK. III-2, BN2A MK. III-3
    (b) Who must comply with this AD? Anyone who wishes to operate 
any of the airplanes identified in paragraph (a) of this AD must 
comply with this AD.
    (c) What problem does this AD address? The actions specified by 
this AD are intended to detect and correct cracks in the engine 
mount bracket. Such a condition could cause the engine mount 
assembly to fail, which could result in the engine separating from 
the airplane and lead to loss of control of the airplane.
    (d) What actions must I accomplish to address this problem? To 
address this problem, you must accomplish the following:

[[Page 54387]]



------------------------------------------------------------------------
           Actions                 Compliance            Procedures
------------------------------------------------------------------------
(1) Inspect the bottom        Initially insect      In accordance with
 corner of the engine          within the next 500   Pilatus Britten
 mounting bracket between      hours time-in-        Norman Service
 the attachment flange and     service (TIS) or      Bulletin SB 275,
 the main part of the          within the next 24    Issue 1, dated
 bracket for cracks.           calendar months       November 30, 2001.
(i) If cracks are found        after the effective
 during any inspection,        date of this AD,
 replace the bracket with a    whichever occurs
 new bracket and continue      first, and
 with the repetitive           repetitively
 inspection requirements of    inspect thereafter
 this AD.                      at intervals not-to-
(ii) If no cracks are found    exceed 500 hours
 during any inspection,        TIS or 1,000
 continue with the             landings, whichever
 repetitive inspection         occurs first.
 requirements of this AD.      Replace cracked
                               bracket prior to
                               further flight
                               after the
                               inspection in which
                               the crack is found.
(2) Send the removed          Within 10 days after  Send the removed
 brackets to the Engineering   removing the          brackets to B-N
 and Design Authority, B-N     bracket or within     Group Limited,
 Group Ltd. and report the     10 days after the     Bembridge, Isle of
 return to FAA. The Office     effective date of     Wight, United
 Management and Budget (OMB)   this AD, whichever    Kingdom PO35 5PR,
 approved the information      occurs later.         and report the
 collection requirements                             return to Doug
 contained in this                                   Rudolph, FAA, at
 regulation under the                                the address in
 provisions of the Paperwork                         paragraph (f) of
 Reduction Act of 1980 (44                           this AD.
 U.S.C. the 3501 et seq.)
 and assigned OMB Control
 Number 2120-0056.
------------------------------------------------------------------------

    (e) Can I comply with this AD in any other way? You may use an 
alternative method of compliance or adjust the compliance time if:
    (1) Your alternative method of compliance provides an equivalent 
level of safety; and
    (2) The Standards Office Manager, Small Airplane Directorate, 
approves your alternative. Submit your request through an FAA 
Principal Maintenance Inspector, who may add comments and then send 
it to the Standards Office Manager.

    Note 1: This AD applies to each airplane identified in paragraph 
(a) of this AD, 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 (e) 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 you have not eliminated the unsafe condition, specific 
actions you propose to address it.

    (f) Where can I get information about any already-approved 
alternative methods of compliance? Contact Doug Rudolph, Aerospace 
Engineer, FAA, Small Airplane Directorate, 901 Locust, Room 301, 
Kansas City, Missouri 64106; telephone: (816) 329-4059; facsimile: 
(816) 329-4090.
    (g) What if I need to fly the airplane to another location to 
comply with this AD? The FAA can issue a special flight permit under 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate your airplane to a location where 
you can accomplish the requirements of this AD.
    (h) How do I get copies of the documents referenced in this AD? 
You may get copies of the documents referenced in this AD from B-N 
Group Limited, Bembridge, Isle of Wight, United Kingdom PO35 5PR; 
telephone: +44 (0) 1983 872511; facsimile: +44 (0) 1983 873246. You 
may view these documents at FAA, Central Region, Office of the 
Regional Counsel, 901 Locust, Room 506, Kansas City, Missouri 64106.

    Note 2: The subject of this AD is addressed in the United 
Kingdom CAA AD Number 005-11-2001, not dated.


    Issued in Kansas City, Missouri, on August 14, 2002.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 02-21356 Filed 8-21-02; 8:45 am]
BILLING CODE 4910-13-P