[Federal Register Volume 61, Number 220 (Wednesday, November 13, 1996)]
[Proposed Rules]
[Pages 58147-58148]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-28983]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 95-ANE-56]
RIN 2120-AA64
Airworthiness Directives; Rolls-Royce plc RB.211-524 Series
Turbofan Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes the adoption of a new airworthiness
directive (AD) that is applicable to Rolls-Royce plc RB.211-524 series
turbofan engines. This proposal would require initial and repetitive
borescope inspections of the head section and meterpanel assembly of
the combustion liner, and replacement, if necessary, with serviceable
parts. In addition, this AD would propose an optional installation of a
front combustion liner with a strengthened head section as a
terminating action to the inspection requirements. This proposal is
prompted by reports of engine fires due to premature engine combustor
distress. The actions specified by the proposed AD are intended to
prevent engine combustor liner deterioration due to thermal fatigue,
which can result in combustor liner and case burn-through and engine
fire.
DATES: Comments must be received by January 13, 1997.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), New England Region, Office of the Assistant Chief
Counsel, Attention: Rules Docket No. 95-ANE-56, 12 New England
Executive Park, Burlington, MA 01803-5299. 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 North America, Inc., 2001 South Tibbs Ave.,
Indianapolis, IN 46241; telephone (317) 230-3995, fax (317) 230-4743.
This information may be examined at the FAA, New England Region, Office
of the Assistant Chief Counsel, 12 New England Executive Park,
Burlington, MA.
FOR FURTHER INFORMATION CONTACT: Eugene Triozzi, Aerospace Engineer,
Engine Certification Office, FAA, Engine and Propeller Directorate, 12
New England Executive Park, Burlington, MA 01803-5299; telephone (617)
238-7148, fax (617) 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 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 95-ANE-56.'' 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 Assistant Chief Counsel,
Attention: Rules Docket No. 95-ANE-56, 12 New England Executive Park,
Burlington, MA 01803-5299.
Discussion
The Civil Aviation Authority (CAA), which is the airworthiness
authority for the United Kingdom, recently notified the Federal
Aviation Administration (FAA) that an unsafe condition may exist on
Rolls-Royce plc (R-R) RB.211-524 series turbofan engines. The CAA
received three reports of engine fires during takeoff and climb. The
investigation revealed that the engine combustor liners had
deteriorated, due to thermal fatigue of either the head section or
meterpanels. In addition, the CAA received reports of premature engine
combustor distress found during routine borescope inspections. This
condition, if not corrected, could result in engine combustor liner
deterioration due to thermal fatigue, which can result in combustor
liner and case burn-through and engine fire.
Rolls-Royce plc has issued Service Bulletin (SB) No. RB.211-72-
B482, Revision 2, dated March 11, 1996, that specifies procedures for
borescope inspections; and SB No. RB.211-72-9764, Revision 2, dated
November 10, 1995, that specifies procedures for installing a front
combustion liner with a strengthened head section manufactured of C263
material. The CAA classified SB No. RB.211-72-B482, Revision 2, dated
March 11, 1996, as mandatory and issued AD 005-07-95, dated March 11,
1996, in order to assure the airworthiness of these engines in the
United Kingdom.
This engine 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, and determined that AD action
is necessary for products of this type design that are certificated for
operation in the United States.
[[Page 58148]]
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 initial and repetitive
borescope inspections of the head section and meterpanel assembly of
the combustion liner, and replacement, if necessary, with serviceable
parts. In addition, this AD would propose an optional installation of a
front combustion liner with a strengthened head section C263 material
as a terminating action to the inspection requirements. The actions
would be required to be accomplished in accordance with the SB's
described previously.
There are approximately 250 engines of the affected design in the
worldwide fleet. There are currently no domestic operators of Rolls-
Royce plc RB.211-524G or -524H series turbofan engines. The FAA
estimates that it would take approximately 8 work hours per engine to
accomplish the proposed inspections, and that the average labor rate is
$60 per work hour. Based on these figures, the cost impact per engine
per inspection is estimated to be $480.
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.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
Rolls-Royce plc: Docket No. 95-ANE-56.
Applicability: Rolls-Royce plc (R-R) Models RB.211-524G and -
524H turbofan engines that have not been modified in accordance with
R-R Service Bulletin (SB) No. RB.211-72-9764, Revision 2, dated
November 10, 1995, installed on but not limited to Boeing 747-400
and 767-300 series aircraft.
Note 1: This airworthiness directive (AD) applies to each engine
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 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 (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 as indicated, unless accomplished
previously. To prevent engine combustor liner deterioration due to
thermal fatigue, which can result in combustor liner and case burn-
through and engine fire, accomplish the following:
(a) Perform initial and repetitive borescope inspections of the
engine combustor liner head section in accordance with the intervals
listed in Section 1.C. Compliance (1), and the procedures described
in Section 1.D. Action (1) of R-R SB No. RB.211-72-B482, Revision 2,
dated March 11, 1996. Prior to further flight, remove combustors
that do not meet the return to service criteria specified in Section
1.E. Acceptance Limits of the SB and replace with serviceable parts.
(b) Perform initial and repetitive borescope inspections of the
meterpanel in accordance with the intervals listed in Section 1.C.
Compliance (2), and the procedures described in Section 1.D. Action
(2) of R-R SB No. RB.211-72-B482, Revision 2, dated March 11, 1996.
Prior to further flight, remove combustors that do not meet the
return to service criteria specified in Section 1.E. Acceptance
Limits of the SB and replace with serviceable parts.
(c) Installation of a front combustion liner with a strengthened
head section in C263 material in accordance with R-R SB No. RB.211-
72-9764, Revision 2, dated November 10, 1995, constitutes
terminating action to the inspection requirements of this AD.
(d) 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. The
request should be forwarded through an appropriate FAA Principal
Maintenance Inspector, who may add comments and then send it to the
Manager, Engine Certification Office.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this airworthiness directive,
if any, may be obtained from the Engine Certification Office.
(e) 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 aircraft to a location where
the requirements of this AD can be accomplished.
Issued in Burlington, Massachusetts, on October 30, 1996.
James C. Jones,
Acting Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. 96-28983 Filed 11-12-96; 8:45 am]
BILLING CODE 4910-13-P
