Airworthiness Directives; Pilatus Britten-Norman Limited BN-2, BN-2A, BN-2B, BN-2T, and BN2A MK. III Series Airplanes

[Federal Register Volume 67, Number 212 (Friday, November 1, 2002)]
[Rules and Regulations]
[Pages 66544-66546]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-27419]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-CE-21-AD; Amendment 39-12926; AD 2002-22-02]
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: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
applies to all Pilatus Britten-Norman Limited (Pilatus Britten-Norman) 
BN-2, BN-2A, BN-2B, BN-2T, and BN2A MK. III series airplanes. This AD 
requires you to repetitively inspect the bottom corner of the engine 
mount bracket for cracks and replace any cracked bracket with a new 
one. This AD is the result of mandatory continuing airworthiness 
information (MCAI) issued by the airworthiness authority for the United 
Kingdom. 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.

DATES: This AD becomes effective on December 20, 2002.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in the regulations as of 
December 20, 2002.

ADDRESSES: You may get the service information 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 this information at the Federal Aviation Administration 
(FAA), Central Region, Office of the Regional Counsel, Attention: Rules 
Docket No. 2002-CE-21-AD, 901 Locust, Room 506, Kansas City, Missouri 
64106; or at the Office of the Federal Register, 800 North Capitol 
Street, NW., suite 700, Washington, DC.

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:

Discussion

What Events Have Caused This 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 Is the Potential Impact if FAA Took No Action?

    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.

Has FAA Taken Any Action to This Point?

    We issued a proposal to amend part 39 of the Federal Aviation 
Regulations (14 CFR part 39) to include an AD that would apply to all 
Pilatus Britten-Norman BN-2, BN-2A, BN-2B, BN-2T, and BN2A MK. III 
series airplanes. This proposal was published in the Federal Register 
as a notice of proposed rulemaking (NPRM) on August 22, 2002 (67 FR 
54384). The NPRM proposed to 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.

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

    The CAA AD and the service information allow 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 AD does 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 
will 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.

Was the Public Invited To Comment?

    The FAA encouraged interested persons to participate in the making 
of this amendment. We did not receive any

[[Page 66545]]

comments on the proposed rule or on our determination of the cost to 
the public.

FAA's Determination

What is FAA's Final Determination on This Issue?

    After careful review of all available information related to the 
subject presented above, we have determined that air safety and the 
public interest require the adoption of the rule as proposed except for 
minor editorial corrections. We have determined that these minor 
corrections:

--Provide the intent that was proposed in the NPRM for correcting the 
unsafe condition; and
--Do not add any additional burden upon the public than was already 
proposed in the NPRM.

Cost Impact

How Many Airplanes Does This AD Impact?

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

What Is the Cost Impact of This AD on Owners/Operators of the Affected 
Airplanes?

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

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

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

------------------------------------------------------------------------
                                                          Total cost per
               Labor cost                   Parts cost       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 
will be required based on the results of the inspection. We have no way 
of determining the number of airplanes that may need such replacement:

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

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

------------------------------------------------------------------------
                                  Parts cost per
           Labor cost                bracket      Total cost per bracket
------------------------------------------------------------------------
48 workhours x $60 per hour =              $714   $2,880 + $714 =
 $2,880 per bracket (2 brackets                    $3,594.
 per engine, 2 engines per
 airplane).
------------------------------------------------------------------------

What Is the Compliance Time of This AD?

    The compliance time of this 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 AD Presented in Both Hours TIS and 
Calendar Time?

    We have established the compliance time of this 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

Does This AD Impact Various Entities?

    The regulations adopted herein will 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 final rule does not have federalism 
implications under Executive Order 13132.

Does This AD Involve a Significant Rule or Regulatory Action?

    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) 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 final

[[Page 66546]]

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, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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 AD to read as follows:

2002-22-02 Pilatus Britten-Norman Limited: Amendment 39-12926; 
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:

------------------------------------------------------------------------
           Actions                 Compliance            Procedures
------------------------------------------------------------------------
(1) Inspect the bottom        Initially inspect     In accordance with
 corner of the engine mount    within the next 500   Pilatus Britten
 bracket between the           hours time-in-        Norman Service
 attachment flange and the     service (TIS) or      Bulletin SB 275,
 main part of the bracket      within the next 24    Issue 1, dated
 for cracks: (i) If cracks     calendar months       November 30, 2001.
 are found during any          after December 20,
 inspections, replace the      2002 (the effective
 bracket with a new bracket    date of this AD),
 and continue with the         whichever occurs
 repetitive inspection         first, and
 requirements of this AD;      repetitively
 (ii) If no cracks are found   inspect thereafter
 during any inspection,        at intervals not-to-
 continue with the             exceed 500 hours
 repetitive inspection         TIS or 1,000
 requirements of this AD.      landings, whichever
                               occurs first.
                               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         Bembridge, Isle of
 return to FAA. The Office     December 20, 2002     Wight, United
 of Management and Budget      (the effective date   Kingdom P035 5PR,
 (OMB) approved the            of this AD),          and report the
 information collection        whichever occurs      return to Doug
 requirements contained in     later.                Rudolph, FAA, at
 this regulation under the                           the address in
 provisions of the Paperwork                         paragraph (f) of
 Reduction Act of 1980 (44                           this AD.
 U.S.C. 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 
Sec. Sec.  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) Are any service bulletins incorporated into this AD by 
reference? Actions required by this AD must be done in accordance 
with Pilatus Britten Norman Service Bulletin SB 275, Issue 1, dated 
November 30, 2001. The Director of the Federal Register approved 
this incorporation by reference under 5 U.S.C. 552(a) and 1 CFR part 
51. You may get copies 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 copies at the FAA, 
Central Region, Office of the Regional Counsel, 901 Locust, Room 
506, Kansas City, Missouri, or at the Office of the Federal 
Register, 800 North Capitol Street, NW, suite 700, Washington, DC.

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

    (i) When does this amendment become effective? This amendment 
becomes effective on December 20, 2002.

    Issued in Kansas City, Missouri, on October 22, 2002.
David R. Showers,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 02-27419 Filed 10-31-02; 8:45 am]
BILLING CODE 4910-13-P

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