[Federal Register Volume 59, Number 205 (Tuesday, October 25, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-26371]


[[Page Unknown]]

[Federal Register: October 25, 1994]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 94-CE-10-AD]

 

Airworthiness Directives; Pilatus Britten-Norman BN2A, BN2B, and 
BN2T Islander Series and BN2A Mk III Trislander 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 Pilatus Britten-Norman BN2A, BN2B, and BN2T 
Islander and BN2A Mk III Trislander series airplanes that are equipped 
with a nose wheel steering disconnect system with either a Modification 
NB/M/503 or Modification NB/M/733 nose undercarriage unit. The proposed 
action would require repetitively inspecting the nose wheel steering 
drive ring for cracks, and replacing any cracked drive ring. A report 
of the rudder pedals jamming in the central position during a takeoff 
on one of the affected airplanes prompted the proposed action. The 
actions specified by the proposed AD are intended to prevent failure of 
the nose wheel steering system because of a cracked drive ring, which 
could result in the inability to move the rudder pedals.

DATES: Comments must be received on or before December 30, 1994.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Central Region, Office of the Assistant Chief 
Counsel, Attention: Rules Docket No. 94-CE-10-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. Delano D. Castle, Program Manager, Brussels Aircraft Certification 
Office, FAA, Europe, Africa, and Middle East Office, c/o American 
Embassy, B-1000 Brussels, Belgium; telephone (322) 513.3830, extension 
2716; facsimile (322) 230.6899; or Mr. John P. Dow, Sr., Project 
Officer, Small Airplane Directorate, Airplane Certification Service, 
FAA, 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. 94-CE-10-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. 94-CE-10-AD, Room 1558, 601 E. 12th Street, 
Kansas City, Missouri 64106.

Discussion

    The Civil Aviation Authority (CAA), which is the airworthiness 
authority for the United Kingdom, recently notified the FAA that an 
unsafe condition may exist on Pilatus Britten-Norman BN2A, BN2B, and 
BN2T Islander and BN2A Mk III Trislander series airplanes that are 
equipped with a nose wheel steering disconnect system with either a 
Modification NB/M/503 or Modification NB/M/733 nose undercarriage unit. 
The CAA advises that the rudder pedals jammed in the central position 
during a takeoff run on a BN2B Islander series airplane. Initial 
investigation revealed that the nose wheel steering drive ring had 
fractured and the broken portion of the ring became snagged in the cut-
away section of frame 19 where the steering cables pass through. This 
caused the inability to move the rudder pedals. Further investigation 
showed that the drive ring had cracked from the small radius of the 
left front lug across the ring and also through the grease nipple hole 
at the rear left side of the ring.
    Pilatus Britten-Norman has issued Service Bulletin No. BN-2/SB.214, 
Issue 1, dated September 23, 1993, which specifies procedures for 
inspecting the nose wheel steering drive ring. In order to assure the 
continued airworthiness of these airplanes in the United Kingdom, the 
CAA listed the actions specified in this service bulletin in the 
Mandatory Aircraft Modifications and Inspections Summary, Issue 8, 
dated March 1994, as UK CAA AD 005-09-93.
    This airplane model is manufactured in the United Kingdom and is 
type certificated for operation in the United States under the 
provisions of Sec. 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, 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 other Pilatus Britten- Norman BN2A, BN2B, and BN2T 
Islander and BN2A Mk III Trislander series airplanes of the same type 
design that are equipped with a nose wheel steering disconnect system 
with either a Modification NB/M/503 or Modification NB/M/733 nose 
undercarriage unit, the proposed AD would require repetitively 
inspecting the nose wheel steering drive ring for cracks, and replacing 
any cracked drive ring. The proposed inspection would be accomplished 
in accordance with Pilatus Britten-Norman Service Bulletin No. BN-2/
SB.214, Issue 1, dated September 23, 1993. The drive ring replacement, 
if necessary, would be accomplished in accordance with the applicable 
maintenance manual.
    The FAA estimates that 15 airplanes in the U.S. registry would be 
affected by the proposed AD, that it would take approximately 1 
workhour per airplane to accomplish the proposed action, and that the 
average labor rate is approximately $55 an hour. Based on these 
figures, the total cost impact of the proposed AD on U.S. operators is 
estimated to be $825. This figure does not take into account the cost 
of repetitive inspections nor the cost of replacing any cracked drive 
ring. The FAA has no way of determining how many repetitive inspections 
each operator would incur over the lifetime of the airplane or how many 
drive rings may be cracked.
    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. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13  [Amended]

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

Pilatus Britten-Norman: Docket No. 94-CE-10-AD.

    Applicability: BN2A, BN2B, and BN2T Islander and BN2A Mk III 
Trislander series airplanes, certificated in any category, that are 
equipped with a nose wheel steering disconnect system with either a 
Modification NB/M/503 or Modification NB/M/733 nose undercarriage 
unit.
    Compliance: Required within the next 100 hours time-in-service 
(TIS), unless already accomplished, and thereafter at intervals not 
to exceed 100 hours TIS.
    To prevent failure of the nose wheel steering system because of 
a cracked drive ring, which could result in the inability to move 
the rudder pedals, accomplish the following:
    (a) Visually inspect the nose wheel steering drive ring for 
cracks in accordance with the ACTION section of Pilatus Britten-
Norman Service Bulletin No. BN-2/SB.214, Issue 1, dated September 
23, 1993. Prior to further flight, replace any cracked nose wheel 
steering drive ring in accordance with the applicable maintenance 
manual.
    (b) Special flight permits may be issued in accordance with 
Secs. 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 
initial or repetitive compliance time that provides an equivalent 
level of safety may be approved by the Manager, Brussels Aircraft 
Certification Office, FAA, Europe, Africa, and Middle East Office, 
c/o American Embassy, B-1000 Brussels, Belgium. The request should 
be forwarded through an appropriate FAA Maintenance Inspector, who 
may add comments and then send it to the Manager, Brussels Aircraft 
Certification Office.

    Note: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Brussels Aircraft Certification Office.

    (d) All persons affected by this directive may obtain copies of 
the document referred to herein upon request to 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 October 19, 
1994.
John R. Colomy,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-26371 Filed 10-24-94; 8:45 am]
BILLING CODE 4910-13-U