[Federal Register Volume 64, Number 165 (Thursday, August 26, 1999)]
[Proposed Rules]
[Pages 46609-46611]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-22194]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 99-NE-30-AD]
RIN 2120-AA64
Airworthiness Directives; Rolls-Royce Limited Dart Series
Turboprop Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
-----------------------------------------------------------------------
SUMMARY: This document proposes the adoption of a new airworthiness
directive (AD) that is applicable to certain Rolls-Royce Limited Dart
series turboprop engines. This proposal would require a one-time visual
inspection of the interior of the switch to determine the type of low
torque switch, and removal from service of unapproved Klixon low torque
switches and replacement with serviceable parts. This proposal is
prompted by the discovery of unapproved low torque switches in fleet
operation. The actions specified by the proposed AD are intended to
prevent possible low torque switch failure, which could result in
failure of a propeller to auto-feather following an engine power loss,
resulting in possible loss of control of the airplane due to high
asymmetric drag.
DATES: Comments must be received by September 27, 1999.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), New England Region, Office of the Regional
Counsel, Attention: Rules Docket No. 99-NE-30-AD, 12 New England
Executive Park, Burlington, MA 01803-5299. Comments may also be
submitted to the Rules Docket by using the following Internet address:
9-ane-adcomment@faa.gov''. Comments may be inspected at this location
between 8:00 a.m. and 4:30 p.m., Monday through Friday, except Federal
holidays.
The service information referenced in the proposed rule may be
obtained from Rolls-Royce Limited, Attn: Dart Engine Service Manager,
East Kilbride, Glasgow G74 4PY, Scotland; telephone: +44 1355-220-200,
fax: +44 1141-778-432. This information may be examined at the FAA, New
England Region, Office of the Regional Counsel, 12 New England
Executive Park, Burlington, MA.
FOR FURTHER INFORMATION CONTACT: James Lawrence, Aerospace Engineer,
Engine Certification Office, FAA, Engine and Propeller Directorate, 12
New England Executive Park, Burlington, MA 01803-5299; telephone (781)
238-7176, fax (781) 238-7199.
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
[[Page 46610]]
interested persons. A report summarizing 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 Number 99-NE-30-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, New England Region, Office of the Regional Counsel,
Attention: Rules Docket No. 99-NE-30-AD, 12 New England Executive Park,
Burlington, MA 01803-5299.
Discussion
The Civil Aviation Authority (CAA), which is the airworthiness
authority for the United Kingdom (UK), recently notified the Federal
Aviation Administration (FAA) that an unsafe condition may exist on
Rolls-Royce Limited (R-R) Dart 506, 510, 511, 514, 525, 526, 529, 530,
531, 532, 535, 542, and 552 series turboprop engines. The CAA advises
that in 1976, failure of a low torque switch resulted in a fatal
military airplane accident. The investigation revealed problems with
the low torque switch that were resolved in a subsequent airworthiness
action.
Recently, however, the CAA has determined that a number of
unapproved, Klixon low torque switches, part number (P/N) 6PS-25-1, are
in service. These low torque switches have not been tested by R-R and
are not approved for use by R-R or the CAA on R-R Dart series turboprop
engines, and are of a different design than the approved, capsule and
snap diaphragm assembly low torque switches. All low torque switches
sense reduction gearbox torque pressure, which is related to engine
power output, and is set to trigger at a predetermined pressure. While
there have been no failures to date of the unapproved Klixon low torque
switches, the CAA and R-R cannot determine whether the switch will
function properly. The low torque switch remains dormant until an
emergency situation, and there are no functional preflight checks of
the low torque switch system to ensure safe operation. This condition,
if not corrected, could result in failure of a propeller to auto-
feather following an engine power loss, resulting in possible loss of
control of the airplane due to high asymmetric drag.
Service Information
R-R has issued Service Bulletin (SB) No. Da61-13, dated December
1996, that specifies procedures for performing a visual inspection of
the interior of the switch to determine the type of low torque switch,
and removal from service of unapproved Klixon low torque switches and
replacement with serviceable parts. Externally, the Klixon low torque
switches are indistinguishable from the approved low torque switches.
The CAA classified this SB as mandatory and issued AD 002-12-96 in
order to assure the airworthiness of these engines in the UK.
This engine model is manufactured in the UK 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, and determined that AD action
is necessary for products of this type design that are certificated for
operation in the United States.
Proposed Actions
Since an unsafe condition has been identified that is likely to
exist or develop on other engines of the same type design registered in
the United States, the proposed AD would require a one-time visual
inspection of the interior of the switch to determine the type of low
torque switch, and removal from service of unapproved Klixon low torque
switches and replacement with approved low torque switches. This action
would be required within 3 months after the effective date of this AD.
The actions would be required to be accomplished in accordance with the
SB described previously.
Economic Analysis
There are approximately 890 engines of the affected design in the
worldwide fleet. The FAA estimates that 139 engines installed on
aircraft of US registry would be affected by this proposed AD, that it
would take approximately 2 work hours per engine to accomplish the
proposed actions, and that the average labor rate is $60 per work hour.
Required parts would cost approximately $12,500 per engine. Based on
these figures, the total cost impact of the proposed AD on US operators
is estimated to be $1,754,180.
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 proposed
regulation (1) is not a ``significant regulatory action'' under
Executive Order 12866; (2) is not a ``significant rule'' under the 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 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, 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.
39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
Rolls-Royce Limited: Docket No. 99-NE-30-AD.
Applicability: Rolls-Royce Limited (R-R) Dart 506, 510, 511,
514, 525, 526, 529, 530, 531, 532, 535, 542, and 552 series
turboprop engines, installed on but not limited to Gulfstream
Aerospace Corp. G-159, British Aerospace HS 748, Fokker Aircraft
F.27, Mitsubishi Heavy Industries YS-11, General Dynamics (Convair)
640 and 600 series, and Vickers Armstrongs (Aircraft Limited)
Viscount.
Note 1: This airworthiness directive (AD) applies to each engine
identified in the
[[Page 46611]]
preceding applicability provision, regardless of whether it has been
modified, altered, or repaired in the area subject to the
requirements of this AD. For engines 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 (b) 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 as indicated, unless accomplished
previously.
To prevent failure of a propeller to auto-feather following an
engine power loss, resulting in possible loss of control of the
airplane due to high asymmetric drag, accomplish the following:
(a) Within 3 months after the effective date of this AD,
accomplish the following in accordance with the Action section of R-
R Service Bulletin (SB) No. Da61-13, dated December 1996:
(1) Remove the switch cover, visually inspect the interior of
the switch and replace the switch cover, all in accordance with the
accomplishment instructions of the SB.
(2) If a Klixon low torque switch, part number (P/N) 6PS-25-1,
is installed, prior to further flight remove the Klixon low torque
switch from service and replace with an approved low torque switch.
(b) An alternative method of compliance or adjustment of the
compliance time that provides an acceptable level of safety may be
used if approved by the Manager, Engine Certification Office (ECO).
Operators shall submit their request through an appropriate FAA
Principal Maintenance Inspector, who may add comments and then send
it to the Manager, ECO.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this airworthiness directive,
if any, may be obtained from the ECO.
(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.
Issued in Burlington, Massachusetts, on August 19, 1999.
David A. Downey,
Assistant Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. 99-22194 Filed 8-25-99; 8:45 am]
BILLING CODE 4910-13-U