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

[Federal Register Volume 63, Number 31 (Tuesday, February 17, 1998)]
[Rules and Regulations]
[Pages 7696-7697]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-3634]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-CE-12-AD; Amendment 39-10329; AD 98-04-17]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes Airworthiness Directive (AD) 97-03-
03, which applies to certain Pilatus Britten-Norman Ltd. (Pilatus) BN-
2, BN-2A, and BN-2B series airplanes that do not have Modification NB/
M/1571 generator terminal diodes installed. AD 97-03-03 currently 
requires the installation of higher capacity diodes on the generator 
switches regardless of whether the airplane is equipped with the 
original 50 amp DC generating system or a Modification NB/M/1148, which 
is a 70 amp system. This action retains the actions of AD 97-03-03, but 
modifies the applicability section to reflect that this AD does not 
apply to Pilatus BN-2, BN-2A, and BN-2B series airplanes with 50 amp DC 
generation systems installed. This AD is the result of reports that the 
applicability section of AD 97-03-03 is incorrect. The actions 
specified by this AD are intended to prevent a loss of electrical power 
to the navigation, communications, and lighting systems, which could 
impair the pilot's ability to maintain control of the airplane.

DATES: Effective March 23, 1998.

    The incorporation by reference of Pilatus Britten-Norman Aircraft 
Manufacturers Service Bulletin (SB) BN-2/SB.228, Issue 2, dated January 
17, 1996, as listed in the regulations was previously approved by the 
Director of the Federal Register as of March 23, 1997 (62 FR 4909, 
February 3, 1997).

ADDRESSES: Service information that applies to this AD may be obtained 
from Pilatus Britten-Norman, Ltd., Bembridge, Isle of Wight, United 
Kingdom, PO35 5PR. This information may also be examined at the Federal 
Aviation Administration (FAA), Central Region, Office of the Regional 
Counsel, Attention: Rules Docket 97-CE-12-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 P. Chudy, Project Officer, 
Small Airplane Directorate, 1201 Walnut, suite 900, Kansas City, 
Missouri, 64106; telephone (816) 426-6932; 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 certain Pilatus BN-2, 
BN-2A, and BN-2B series airplanes equipped with Pilatus Modification 
NB/M/1148 (a 70 amp generating system), but without generator terminal 
diodes installed in accordance with Modification NB/M/1571, was 
published in the Federal Register on July 7, 1997, (62 FR 36240). The 
action proposed to supersede AD 97-03-03, which requires installing 
type 60S6 diodes on the terminals of the STBD (RIGHT) GEN and PORT 
(LEFT) GEN switches (SW2 and SW3), regardless of the generating system 
being used on the airplane. This superseding action retains the same 
action as AD 97-03-03, but changes the applicability section so that it 
applies only to the Pilatus BN-2, BN-2A, and BN-2B airplanes that have 
Modification NB/M/1148 (70 amp DC generation system) incorporated, and 
do not have Pilatus Modification NB/M/1571 (Introduction of Increased 
Rated Diode--70 amp DC generation system) incorporated. This action 
would not apply to certain Pilatus BN-2, BN-2A, and BN-2B series 
airplanes with a 50 amp DC generation system installed.
    Accomplishment of this action would be in accordance with Pilatus 
Britten-Norman Ltd. Service Bulletin No. BN-2/SB.228, Issue 2, dated 
January 17, 1996.

The FAA's Determination

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. No comments were received on the 
proposed rule or the FAA's determination of the cost to the public.
    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 7697]]

Cost Impact

    The FAA estimates that 116 airplanes currently on the U.S. registry 
will be affected by this AD, that it will take approximately 1 workhour 
per airplane to accomplish this action, and that the average labor rate 
is approximately $60 an hour. Parts cost approximately $40 per 
airplane. Based on these figures, the total cost impact of this AD on 
U.S. operators is estimated to be $11,600 for the fleet or $100 per 
airplane. For purposes of estimating the cost of this AD, the FAA is 
presuming that none of the owners/operators have accomplished any of 
the actions on any of the affected airplanes.

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 USC 106(g), 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by removing airworthiness directive 
(AD) 97-03-03, Amendment No. 39-9909, and by adding a new AD to read as 
follows:

98-04-17-Pilatus Britten-Norman LTD.: Amendment No. 39-10329; Docket 
No. 97-CE-12-AD; Supersedes AD 97-03-03, Amendment 39-9909.

    Applicability: BN-2, BN-2A, and BN-2B series airplanes (all 
serial numbers), certificated in any category, that have Pilatus 
Britten-Norman (Pilatus) Modification NB/M/1148 (70 amp DC 
Generation System) incorporated, and do not have Pilatus 
Modification NB/M/1571 (Introduction of Increased Rated Diode-70 amp 
DC Generation System) incorporated.

    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 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 hours time-in-service 
(TIS) after the effective date of this AD, unless already 
accomplished.
    To prevent loss of electrical power to the navigation, 
communications and lighting systems, which could impair the pilot's 
ability to maintain control of the airplane, accomplish the 
following:
    (a) Remove the diodes (quantity 2, part number (P/N) 340502014, 
type 10B1 or 10D1) installed on the terminals of the STBD (RIGHT) 
GEN and PORT (LEFT) GEN switches (SW2 and SW3), and install new 
approved diodes (quantity 2, P/N NB-81-5873, type 60S6) in 
accordance with the Accomplishment Instructions section in Pilatus 
Britten-Norman Aircraft Manufacturers Service Bulletin (SB) BN-2/
SB.228, Issue 2, dated January 17, 1996.
    (b) Accomplishment of paragraph (a) of this AD is considered 
incorporation of Modification NB/M/1571.
    (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 
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. Alternative methods of compliance previously approved 
for AD 97-03-03 are considered approved for this AD.

    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) The removal and installation required by this AD shall be 
done in accordance with Pilatus Britten-Norman Aircraft 
Manufacturers Service Bulletin (SB) BN-2/SB.228, Issue 2, dated 
January 17, 1996.
    (1) This incorporation by reference of Pilatus Britten-Norman 
Aircraft Manufacturers Service Bulletin (SB) BN-2/SB.228, Issue 2, 
dated January 17, 1996 was approved previously by the Director of 
the Federal Register as of March 23, 1997 (62 FR 4909, February 3, 
1997).
    (2) Copies may be obtained from Pilatus Britten-Norman, Ltd., 
Bembridge, Isle of Wight, United Kingdom, PO35 5PR. Copies may be 
inspected at the FAA, Central Region, Office 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.
    (f) This amendment supersedes AD 97-03-03, Amendment 39-9909.
    (g) This Amendment (39-10329) becomes effective on March 23, 
1998.

    Issued in Kansas City, Missouri, on February 6, 1998.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 98-3634 Filed 2-13-98; 8:45 am]
BILLING CODE 4910-13-U

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