Airworthiness Directives; Pilatus Britten-Norman Ltd. BN-2, BN- 2A, BN-2B, and BN-2T Series Airplanes

[Federal Register Volume 63, Number 152 (Friday, August 7, 1998)]
[Rules and Regulations]
[Pages 42205-42206]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-20837]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-CE-112-AD; Amendment 39-10690; AD 98-16-14]
RIN 2120-AA64


Airworthiness Directives; Pilatus Britten-Norman Ltd. BN-2, BN-
2A, BN-2B, and BN-2T 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 Ltd. (Pilatus Britten-Norman) BN-
2, BN-2A, BN-2B, and BN-2T series airplanes. This AD requires replacing 
the attachment bolts, nuts and washers of the lower fitting of the main 
landing gear (MLG), and adjusting the torque values of the nuts. 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 prevent the bolts that 
attach the lower fitting of the MLG to the nacelle from becoming 
threadbound, which could result in structural failure of the MLG with 
consequent loss of control of the airplane during takeoff, taxi, or 
landing operations.

DATES: Effective September 21, 1998.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of September 21, 1998.

ADDRESSES: Service information that applies to this 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 may also be examined at the Federal Aviation 
Administration (FAA), Central Region, Office of the Regional Counsel, 
Attention: Rules Docket No. 97-CE-112-AD, Room 1558, 601 E. 12th 
Street, 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: Mr. Roger Chudy, Aerospace Engineer, 
Small Airplane Directorate, Aircraft Certification Service, 1201 
Walnut, suite 900, Kansas City, Missouri 64106; telephone: (816) 426-
6934; facsimile: (816) 426-2169.

SUPPLEMENTARY INFORMATION:

Events Leading to the Issuance of This AD

    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, and BN-2T series airplanes was published in 
the Federal Register as a notice of proposed rulemaking (NPRM) on March 
19, 1998 (63 FR 13379). The NPRM proposed to require replacing the 
washers on the attachment bolts of the lower fitting of the MLG. 
Accomplishment of the proposed action as specified in the NPRM would be 
in accordance with Pilatus Britten-Norman Service Bulletin BN2/SB.231, 
Initial Issue, dated October 17, 1996.
    The NPRM was the result of mandatory continuing airworthiness 
information (MCAI) issued by the airworthiness authority for the United 
Kingdom.
    After issuance of the NPRM, Pilatus Britten-Norman informed the FAA 
that Service Bulletin BN2/SB.231 has been revised to the Issue 2 status 
(dated October 1, 1997). This revision changes the procedures to 
specify replacing the attachment bolts and nuts of the lower fitting of 
the MLG instead of re-using the existing bolts and nuts. This service 
information also specifies procedures to adjust the torque loading 
values of the bolts.
    In addition, the FAA has realized that the Model BN-2T-4R airplanes 
were inadvertently omitted from the proposed AD. At that time, the FAA 
determined that the Model BN-2T-4R airplanes are of similar type design 
to those currently listed in the NPRM.
    This prompted the FAA to issue 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 BN-2T-4R series airplanes. This proposal was published in the 
Federal Register as a supplemental NPRM on May 28, 1998 (63 FR 29159). 
The supplemental NPRM proposed to also require replacing the attachment 
bolts and nuts of the lower fitting of the MLG and adjusting the torque 
values of the nuts. Accomplishment of the proposed action as specified 
in the supplemental NPRM would be in accordance with the service 
information previously referenced.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the one comment received.

Comment Disposition

    Pilatus Britten-Norman states that the proposed AD should not apply 
to the Model BN-2T-4R airplanes. These airplanes utilize a different 
type wing and an uprated landing gear construction from the rest of the 
affected models.
    After re-examining all information related to this subject, the FAA 
concurs and has removed the Model BN-2T-4R airplanes from the final 
rule.

The FAA's Determination

    After careful review of all available information related to the 
subject presented above, the FAA has determined that air safety and the 
public interest require the adoption of the rule as proposed except for 
minor editorial corrections. The FAA has determined that these minor 
corrections will not change the meaning of the AD and will not add any 
additional burden upon the public than was already proposed.

[[Page 42206]]

Cost Impact

    The FAA estimates that 80 airplanes in the U.S. registry will be 
affected by this AD, that it will take approximately 3 workhours per 
airplane to accomplish this action, and that the average labor rate is 
approximately $60 an hour. Parts cost approximately $10 per airplane. 
Based on these figures, the total cost impact of this AD on U.S. 
operators is estimated to be $15,200, or $190 per airplane.

Regulatory Impact

    The regulations adopted herein will 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 final 
rule does 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) 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 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, pursuant to 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. Section 39.13 is amended by adding a new airworthiness directive 
(AD) to read as follows:

98-16-14 Pilatus Britten-Norman Ltd: Amendment 39-10690; Docket No. 
97-CE-112-AD.

    Applicability: Models BN-2, BN-2A, BN-2A-3, BN-2A-6, N-2A-8, BN-
2A-2, 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, and BN-2T 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 (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 50 landings after the 
effective date of this AD, unless already accomplished.

    Note 2: The compliance time of this AD is presented in landings 
instead of hours time-in-service (TIS). If the number of landings is 
unknown, hours TIS may be used by multiplying the number of hours 
TIS by 1.5.

    To prevent the bolts that attach the lower fitting of the main 
landing gear (MLG) to the nacelle from becoming threadbound, which 
could result in structural failure of the MLG with consequent loss 
of control of the airplane during takeoff, taxi, or landing 
operations, accomplish the following:
    (a) Replace the attachment bolts, nuts, and washers of the lower 
fitting of the MLG, in accordance with Pilatus Britten-Norman 
Service Bulletin No. BN2/SB.231, Issue 2, dated October 1, 1997.
    (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 an 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, 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 3: 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 Pilatus 
Britten-Norman Service Bulletin BN2/SB.231, Issue 2, dated October 
1, 1997, should be directed to Pilatus Britten-Norman Limited, 
Bembridge, Isle of Wight, United Kingdom PO35 5PR; telephone: 44-
1983 872511; facsimile: 44-1983 873246. 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.
    (e) The replacement required by this AD shall be done in 
accordance with Pilatus Britten-Norman Service Bulletin No. BN2/
SB.231, Issue 2, dated October 1, 997. This incorporation by 
reference was approved by the Director of the Federal Register in 
accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be 
obtained from Pilatus Britten-Norman Limited, Bembridge, Isle of 
Wight, United Kingdom PO35 5PR. Copies may be inspected at the FAA, 
Central Region, ffice of the Regional Counsel, Room 1558, 601 E. 
12th Street, Kansas City, Missouri, or at the Office of the Federal 
Register, 800 North Capitol Street, NW, suite 700, Washington, DC.

    Note 4: The subject of this AD is addressed in British AD No. 
008-10-96, dated January 31, 1997.

    (f) This amendment becomes effective on September 21, 1998.

    Issued in Kansas City, Missouri, on July 28, 1998.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 98-20837 Filed 8-6-98; 8:45 am]
BILLING CODE 4910-13-U

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