[Federal Register Volume 61, Number 164 (Thursday, August 22, 1996)]
[Proposed Rules]
[Pages 43319-43320]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-21373]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 96-CE-33-AD]
RIN 2120-AA64


Airworthiness Directives; Pilatus Britten-Norman BN2, BN2A, and 
BN2B 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 certain Pilatus Britten-Norman BN2, BN2A, and 
BN2B series airplanes that have been modified with a 70 amp direct 
current (DC) Generation System. The proposed action would require 
removing the 70 amp terminal diodes and installing new terminal diodes 
with a higher amp rating. Reports from operators that one or both 
diodes were failing prompted the proposed action. The actions specified 
by the proposed AD are intended to prevent loss of electrical power to 
the navigation, communications and light systems, which could impair 
the pilots ability to maintain control of the airplane.

DATES: Comments must be received on or before October 21, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Central Region, Office of the Assistant Chief 
Counsel, Attention: Rules Docket No. 96-CE-33-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, Ltd., Bembridge, Isle of Wight, United 
Kingdom, PO35 5PR. This information also may be examined at the Rules 
Docket at the address above. Comments may be inspected at this location 
between 8 a.m. and 4 p.m., Monday through Friday, holidays excepted.

FOR FURTHER INFORMATION CONTACT: Dorenda Baker, Program Manager, 
Brussels Aircraft Certification Division, FAA, Europe, Africa and the 
Middle East Office, c/o American Embassy, b-1000, Brussels, Belgium; 
telephone (322) 508.27.15, facsimile (322) 230.6899 or Mr. Jeffrey 
Morfitt, Project Officer, Small Airplane Directorate, 1201 Walnut, 
suite 900, Kansas City, Missouri, 64106; telephone (816) 426-6934, 
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. 96-CE-33-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    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. 96-CE-33-AD, Room 1558, 601 E. 12th Street, 
Kansas City, Missouri 64106.

Discussion

    The Civil Airworthiness Authority (CAA), which is the airworthiness 
authority for the United Kingdom, recently notified the FAA that an 
unsafe condition may exist on certain Pilatus Britten-Norman (Pilatus) 
BN2, BN2A, and BN2B series airplanes that have been modified with a 70 
amp DC Generation System. The CAA reports that several owners/operators 
of these airplanes have experienced diode failure which leads to 
generator failure during flight. Further investigation has shown that 
the diode rating is not sufficient to maintain the generators used to 
operate the navigation, communication, and light systems. This 
condition, if not detected and corrected, could result in loss of power 
to the navigation, communication, and light systems which could impair 
the pilot's ability to maintain control of the airplane.
    Pilatus has issued Service Bulletin (SB) BN-2/SB.228, Issue 2, 
dated January 17, 1996 which specifies procedures for removing the 
diodes (type 10B1 or 10D1) and installing diodes (type 60S6) with a 
higher amp rating.
    The CAA classified this service bulletin as mandatory and issued 
CAA AD No. 004-01-96, in order to assure the continued airworthiness of 
these airplanes in the United Kingdom.
    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 between the 
United Kingdom and the United States. Pursuant to this bilateral 
airworthiness agreement, the CAA has kept the FAA informed of the 
situation described above. The FAA has examined the findings of the 
CAA, reviewed all available information including the service 
information referenced above, and determined that AD action is 
necessary for products of this type design that are certificated for 
operation in the United States.
    Since an unsafe condition has been identified that is likely to 
exist or develop in Pilatus BN2, BN2A, and BN2B series airplanes of the 
same type design registered in the United States, the proposed would 
require removing the diodes (type 10B1 or 10D1) installed on the 
terminals of the ``STBD (RIGHT) GEN'' and ``PORT (LEFT) GEN'' switches 
(SW2 and SW3), and installing new approved diodes that are type 60S6. 
Accomplishment of the proposed action would be in accordance with 
Pilatus SB BN-2/SB.228, Issue 2, dated January 17, 1996.
    The FAA estimates that one airplane currently on the U.S. registry 
would be affected by the proposed AD, that it would take approximately 
one workhour per airplane to accomplish the proposed 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 the proposed AD on U.S. operators is estimated to be $100.

[[Page 43320]]

    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 AD 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), 40101, 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding a new airworthiness directive 
(AD) to read as follows:

    Pilatus Britten-Norman (Pilatus): Docket No. 96-CE-33-AD.

    Applicability: BN2, BN2A, and BN2B series airplanes (all serial 
numbers) that have been modified with a 70 amp direct current (DC) 
Generation System, 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 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 light 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 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, part number NB-81-5873, type 60S6) in 
accordance with the Accomplishment Instructions section in Pilatus 
Britten-Norman Service Bulletin BN-2/SB.228, Issue 2, dated January 
17, 1996.
    (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 can 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, Brussels Aircraft Certification Division, 
FAA, Europe, Africa and the Middle East Office, c/o American 
Embassy, B-1000, Brussels, Belgium or Mr. Jeffrey Morfitt, Project 
Officer, 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, Brussels Aircraft Certification Division or 
the Small Airplane Directorate.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Brussels Aircraft Certification Division or the 
Small Airplane Directorate.

    (d) All persons affected by this directive may obtain copies of 
the document referred to herein upon request Pilatus Britten-Norman, 
Ltd., Bembridge, Isle of Wight, United Kingdom, PO35 5PR; or may 
examine this document at the FAA, Central Region, Office of the 
Assistant Chief Counsel, Room 1558, 601 E. 12th Street, Kansas City, 
Missouri 64106.

    Issued in Kansas City, Missouri, on August 15, 1996.
Carolanne L. Cabrini,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-21373 Filed 8-21-96; 8:45 am]
BILLING CODE 4910-13-U