[Federal Register Volume 63, Number 110 (Tuesday, June 9, 1998)]
[Proposed Rules]
[Pages 31370-31372]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-15203]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 97-CE-111-AD]
RIN 2120-AA64
Airworthiness Directives; Pilatus Britten-Norman Ltd. BN-2, BN-
2A, BN-2B, and BN-2A 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 certain Pilatus Britten-Norman Ltd. (PBN) BN-
2, BN-2A, BN-2B, and BN-2A MK.III series airplanes that are equipped
with a PBN Modification NB/M/256, 50A generator system. The proposed
action would require inspecting the airplanes that are equipped with a
50A generator system for a 70A generator. If a 70A generator is
installed, the proposed action would require replacing the 70A
generator with a 50A generator, or (for the BN-2, BN-2A, and BN-2B
series only) upgrading the airplane generator system to a 70A system to
match the 70A generator. The proposed AD is the result of mandatory
continuing airworthiness information (MCAI) issued by the airworthiness
authority for the United Kingdom. The actions specified by the proposed
AD are intended to prevent damage to the components of the electrical
system, which could result in electrical system failure during critical
phases of flight.
DATES: Comments must be received on or before July 17, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Central Region, Office of the Regional Counsel,
Attention: Rules Docket No. 97-CE-111-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.
FOR FURTHER INFORMATION CONTACT: Mr. Roger Chudy, Project Officer, FAA,
Small Airplane Directorate, 1201 Walnut, suite 900, Kansas City,
Missouri, 64106; telephone (816) 426-6932, 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. 97-CE-111-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 Regional Counsel, Attention:
Rules Docket No. 97-CE-111-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, notified the FAA that an unsafe
condition may exist on certain PBN BN-2, BN-2A, BN-2B, and BN-2A MK.III
series airplanes. The CAA reports that some operators have had 70A
generators installed on 50A systems, which may damage the electrical
system's components. The 50A generator system, which is known as PBN
Modification NB/M/256, is not designed to work with a higher ampere
generator.
These conditions, if not corrected, could result in damage to the
electrical systems with consequent failure during critical phases of
flight.
Relevant Service Information
PBN has issued Service Bulletin No. BN-2/SB.229, dated October 17,
1996, which specifies procedures for inspecting for a 70A generator on
PBN BN-2, BN-2A, BN-2B, and BN-2A MK.III series airplanes that are
equipped with PBN Modification NB/M/256 (a 50A generator system). If a
70A generator is installed, the service information specifies
procedures for replacing the 70A generator with a 50A generator, or
(for the BN-2, BN-2A, and BN-2B series only) installing PBN
Modification NB/M/1148, which incorporates a 70A generator system.
The CAA classified this service bulletin as mandatory and issued
British
[[Page 31371]]
AD 007-10-96, not dated, in order to assure the continued airworthiness
of these airplanes in United Kingdom.
The FAA's Determination
This airplane model is manufactured in the United Kingdom and is
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 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.
Explanation of the Provisions of the Proposed AD
Since an unsafe condition has been identified that is likely to
exist or develop in other PBN BN-2, BN-2A, BN-2B, and BN-2A MK.III
series airplanes of the same type design registered in the United
States, the FAA is proposing AD action. The proposed AD would require:
Inspecting the airplane for a 70A generator installed on a
50A generator system;
For PBN BN-2A MK.III series airplanes, if a 70A generator
is installed on a 50A generator system, the proposed AD would require
replacing the 70A generator with a 50A generator;
For the BN-2, BN-2A, and BN-2B series airplanes, the
proposed AD would require either replacing the 70A generator with a 50A
generator; or upgrading the 50A generator system to a 70A generator
system by installing PBN Modification NB/M/1148; and,
If PBN Modification NB/M/1148 is installed, the proposed
action would require the installation of PBN Modification NB/M/1571
(which improves the diodes on the 70A generator system).
Accomplishment of the proposed inspection and installation or
replacement would be in accordance with PBN Service Bulletin No. BN-2/
SB.229, dated October 17, 1996.
The Proposed Action As It Relates to Current AD's
The FAA has recently issued AD 98-04-17, Amendment 39-10329 (63 FR
7696, February 17, 1998), which requires that any PBN BN-2, BN-2A, and
BN-2B series airplanes that are not equipped with Modification NB/M/
1571, but are equipped with PBN Modification NB/M/1148 (which
incorporates the 70A generator system) should also be equipped with PBN
Modification NB/M/1571. AD 98-04-17 does not affect any airplane that
is equipped with a 50A generator system.
Since the proposed AD provides an option that would require
accomplishment of AD 98-04-17, the FAA is including reference of other
similar AD requirements. Operators of BN-2, BN-2A, and BN-2B series
airplanes that have 70A generators installed on 50A generator systems,
and choose the proposed option of upgrading their 50A generator system
to a 70A generator system, would be subject to the requirements in AD
98-04-17. This proposed action would concurrently require installing
higher amperage diodes in the 70A generator.
Pilatus Britten-Norman has informed the FAA that Modification NB/M/
1148 or Modification NB/M/1571 is not approved for installation on the
BN-2A MK.III series airplanes.
Cost Impact
The FAA estimates that 80 airplanes in the U.S. registry would be
affected by the proposed AD, that it would take approximately 7
workhours per airplane to accomplish the proposed action, and that the
average labor rate is approximately $60 an hour. Parts cost
approximately $500 per airplane. Based on these figures, the total cost
impact of the proposed AD on U.S. operators is estimated to be $73,600,
or $920 per airplane.
Proposed Calendar Compliance Time
The condition addressed by the proposed AD is not caused by actual
hours time-in-service (TIS) of the aircraft where the affected
generators are installed. The need for the generator system
modification or replacement has no correlation to the number of times
the equipment is utilized or the age of the equipment. For this reason,
the compliance time of the proposed AD is presented in calendar time
instead of hours TIS.
Regulatory Impact
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 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), 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 Ltd.: Docket No. 97-CE-111-AD.
Applicability: 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-2A MK.III, BN-2A MK.111-2, and BN-
2A MK.111-3 airplanes, all serial numbers, certificated in any
category, that are equipped with PBN Modification NB/M/256, a 50A
Generator System.
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
[[Page 31372]]
been eliminated, the request should include specific proposed
actions to address it.
Compliance: Required within the next 3 calendar months after the
effective date of this AD, unless already accomplished.
To prevent damage to the components of the generator system,
which could result in generator system failure during critical
phases of flight, accomplish the following:
(a) Inspect the generator system for the installation of a 70A
generator in accordance with the Inspection section of Pilatus
Britten-Norman (PBN) Service Bulletin (SB) No. BN-2/SB.229, dated
October 17, 1996.
(b) If a 70A generator is installed, accomplish the following,
as applicable:
(1) For 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, and BN-2B-27 airplanes, prior to further flight, either:
(i) Replace the 70A generator with a 50A generator in accordance
with the Replacement section of PBN SB No. BN-2/SB.229, dated
October 17, 1996; or
(ii) Incorporate PBN Modification NB/M/1148 (a 70A generator
system) in accordance with the appropriate Pilatus Britten-Norman
maintenance manual; and, incorporate PBN Modification NB/M/1571
(installation of improved generator diodes) in accordance with PBN
SB No. BN-2/228, Issue 2, dated January 17, 1996.
Note 2: Incorporating PBN Modification NB/M/1571 is the same
action required by AD 98-04-17, Amendment 39-10329.
(2) For Models BN-2A MK.III, BN-2A MK.111-2, and BN-2A MK.111-3
airplanes, prior to further flight, replace the 70A generator with a
50A generator in accordance with the Replacement section of PBN SB
No. BN-2/SB.229, dated October 17, 1996.
(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.
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.
(e) Questions or technical information related to PBN Service
Bulletin No. BN-2/SB.229, dated October 17, 1996, or Pilatus
Britten-Norman Service Bulletin No. BN-2/SB.228, dated January 17,
1996, should be directed to Pilatus Britten-Norman, Ltd., Bembridge,
Isle of Wight, United Kingdom, PO35 5PR. 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.
Note 4: The subject of this AD is addressed in British AD 007-
10-96, not dated.
Issued in Kansas City, Missouri, on June 1, 1998.
Ronald K. Rathgeber,
Acting Manager, Small Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 98-15203 Filed 6-8-98; 8:45 am]
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