[Federal Register: March 25, 2003 (Volume 68, Number 57)]
[Proposed Rules]
[Page 14355-14359]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr25mr03-26]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 2002-NE-16-AD]
RIN 2120-AA64
Airworthiness Directives; Rolls-Royce plc. RB211-535 Turbofan
Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: The Federal Aviation Administration (FAA) proposes to
supersede an existing airworthiness directive (AD), applicable to
Rolls-Royce plc. (RR) models RB211-535E4-37, RB211-535E4-B-37, and
RB211-535E4-B-75 turbofan engines, with certain part number (P/N) low
pressure (LP) turbine stage 2 discs installed. That AD currently
requires establishing new reduced LP turbine stage 2 disc cyclic
limits. That AD also requires removing from service affected discs that
already exceed the new reduced cyclic limit, and removing other
affected discs before exceeding their cyclic limits, using a drawdown
schedule. This proposal would require changing certain cyclic limits,
changing the effective date of certain disc cyclic lives, and would
allow intermix of Flight Plan A and Flight Plan B intermix
calculations. This proposal is prompted by a reassessment of the
thermal and stress data from recent operational experience and comments
received from operators on the current AD. The actions specified by the
proposed AD are intended to prevent LP turbine stage 2 disc failure,
which could result in uncontained engine failure and possible loss of
the airplane.
DATES: Comments must be received by May 27, 2003.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), New England Region, Office of the Regional
Counsel, Attention: Rules Docket No. 2002-NE-16-AD, 12 New England
Executive Park, Burlington, MA 01803-5299. Comments may be inspected,
by appointment, at this location between 8 a.m. and 4:30 p.m., Monday
through Friday, except Federal holidays. Comments may also be sent via
the Internet using the following address: 9-ane-adcomment@faa.gov.
Comments sent via the Internet must contain the docket number in the
subject line.
The service information referenced in the proposed rule may be
obtained from Rolls-Royce plc, P.O. Box 31 Derby, DE24 8BJ, United
Kingdom; telephone 011-44-1332-242424; fax 011-44-1332-249936. 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: Ian Dargin, Aerospace Engineer, Engine
Certification Office, FAA, Engine and Propeller Directorate, 12 New
England Executive Park, Burlington, MA 01803-5299; telephone (781) 238-
7178; 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 action may be changed in
light of the comments received.
[[Page 14356]]
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 action must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 2002-NE-16-AD.'' The postcard will be date stamped and
returned to the commenter.
Availability of NPRM's
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. 2002-NE-16-AD, 12 New England Executive
Park, Burlington, MA 01803-5299.
Discussion
On November 8, 2002, the FAA issued AD 2002-23-08, Amendment 39-
12952 (67 FR 71094, November 29, 2002), to require establishing new
reduced LP turbine stage 2 disc cyclic limits, to require removing from
service affected discs that already exceed the new reduced cyclic
limit, and to remove other affected discs before exceeding their cyclic
limits, using a drawdown schedule. The Civil Aviation Authority (CAA),
which is the airworthiness authority for the United Kingdom (U.K.), had
notified the FAA that an unsafe condition may exist on RR models RB211-
535E4-37, RB211-535E4-B-37, and RB211-535E4-B-75 turbofan engines. The
CAA advised that the manufacturer had performed a reassessment of the
safe cyclic limits of LP turbine stage 2 discs, P/Ns UL11508, UL17141,
UL18947, UL29029, and UL37352. The cyclic limits of these discs were
reduced based on more recent thermal and stress data obtained from
operational experience. This condition, if not corrected, could result
in uncontained engine failure and possible loss of the airplane.
Since AD 2002-23-08 was issued, another reassessment of the thermal
and stress data obtained through operational experience was made, and
comments were received from operators on the current AD.
Comments
Interested persons have been afforded an opportunity to comment on
final rule; request for comments AD 2002-23-08. Due consideration has
been given to the comments received.
Request To Change Table 1 Life Limit
Two commenters request that the Flight Plan A life limit for item
(1) December 31, 2001, listed in Table 1, be changed from 22,500
cycles-since-new (CSN) to the value of 23,200 CSN. The commenters state
that the 22,500 CSN value does not agree with the corresponding table
value in mandatory service bulletin (MSB) RB.211-72-D181, Revision 3,
dated August 16, 2002.
The FAA agrees. We have changed item (1) of Table 1 of this
proposed rule to 23,200 CSN.
Request To Change Effective Date of Disc Cyclic Life
Nine commenters request that the effective date of the disc cyclic
life in Table 2 and Table 3 be changed from ``On the effective date of
this AD'' to agree with the corresponding table value of ``As of
December 31, 2000'' in MSB RB.211-72-D181, Revision 3, dated August 16,
2002.
The FAA agrees. We have changed the first columns of Table 2 and
Table 3.
Request To Change Drawdown Schedule
Six commenters request the drawdown schedule in the AD be changed
to coincide with the schedule in MSB RB.211-72-D181, Revision 3. The
commenters have identified differences in various drawdown schedule
cyclic limits between the AD and the MSB, and state the AD limits are
more restrictive.
The FAA agrees. We have changed this proposed rule to coincide as
much as possible with the drawdown schedule in the MSB.
Request for an Allowance for Flight Plan Intermix
One commenter states that the AD does not allow for Flight Plan A
and Flight Plan B intermix count conditions and that this could result
in a lower cyclic limit than required by the MSB.
The FAA agrees. We have incorporated the intermix note from the MSB
into this proposed rule.
Request To Incorporate Four Tables from the MSB Versus the Three Tables
in AD
One commenter states that the drawdown requirements and inspection
were provided in four tables in MSB RB.211-72-D181, Revision 3, and
that the AD should adopt the same tabular format. The commenter
believes this would reduce the potential for confusion among the
operators, eliminate contradiction between the MSB and AD, and ensure
the original safety issues will be addressed.
The FAA partially agrees. It is unclear which four tables the
commenter is referring to since they are not numbered in the MSB.
However, in an effort to clarify this information, we have added
additional levels of detail to Table 2 and Table 3.
Manufacturer's Service Information
Rolls-Royce plc. issued MSB RB.211-72-D181, Revision 3, dated
August 16, 2002, that specifies a drawdown schedule for removing from
service affected LP turbine stage 2 discs, using new Time Limits Manual
(TLM) cyclic limits. This MSB provides a scheduled reduction, by engine
and flight plan, of LP turbine stage 2 disc lives until the full life-
cycle reduction on December 31, 2005.
This MSB also provides instructions for performing a one-time on-
wing eddy current inspection for cracks of affected LP turbine stage 2
discs to allow a disc to remain in service for an additional 3,000
cycles, if it does not exceed the new, lower TLM cyclic limit. The CAA
has classified this service bulletin as mandatory and issued AD 006-05-
2001 in order to assure the airworthiness of these Rolls-Royce plc.
turbofan engines in the U.K.
Bilateral Agreement Information
This engine model is manufactured in the U.K. 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 Requirements of This AD
Since an unsafe condition has been identified that is likely to
exist or develop on other RR models RB211-535E4-37, RB211-535E4-B-37,
and RB211-535E4-B-75 turbofan engines of the same type design, the
proposed AD would require:
[sbull] Reducing the LP turbine stage 2 disc life-cyclic limits;
AND
[[Page 14357]]
[sbull] Removing from service affected discs that already exceed
the new reduced cyclic limits; AND
[sbull] Removing other affected discs before exceeding their cyclic
limits, using a drawdown schedule.
The actions would be required to be done in accordance with the MSB
described previously.
Economic Analysis
There are approximately 1,253 engines of the affected design in the
worldwide fleet. The FAA estimates that 788 engines installed on
airplanes of U.S. registry would be affected by this proposed AD. The
FAA also estimates that it would take approximately 12 work hours per
engine to perform each of the proposed inspections and 300 work hours
per engine to perform the proposed disc removals. The average labor
rate is $60 per work hour. Required parts would cost approximately
$60,190 per engine. Based on these figures, the total cost of the
proposed AD for performing one inspection per engine and removing all
788 discs, to U.S. operators is estimated to be $62,181,080.
Regulatory Analysis
This proposed rule does not have federalism implications, as
defined in Executive Order 13132, because it would not have a
substantial direct effect 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.
Accordingly, the FAA has not consulted with state authorities prior to
publication of this proposed rule.
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 removing Amendment 39-12952 (67 FR
71094, November 29, 2002), and by adding a new airworthiness directive,
to read as follows:
Rolls-Royce plc.: Docket No. 2002-NE-16-AD. Supersedes AD 2002-23-
08, Amendment 39-12952.
Applicability: This airworthiness directive (AD) is applicable
to Rolls-Royce plc. (RR) models RB211-535E4-37, RB211-535E4-B-37,
and RB211-535E4-B-75 turbofan engines, with low pressure (LP)
turbine stage 2 discs part numbers (P/N's) UL11508, UL17141,
UL18947, UL29029, and UL37352 installed. These engines are installed
on, but not limited to, Boeing 757 and Tupolev Tu204 airplanes.
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 (h) 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: Compliance with this AD is required as indicated,
unless already done.
To prevent LP turbine stage 2 disc failure, which could result
in an uncontained engine failure and possible loss of the airplane,
do the following:
Cycle Limits
(a) Change the RR Time Limits Manual cyclic limits for LP
turbine stage 2 discs as specified in the following Table 1:
Table 1.--Time Limits Manual (TLM) Cyclic Limits
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Life limits for RB211-535E4
engines operating in flight Life limits for RB211-535E4 engines
Date of reduced life limit plan A, and RB211-535E4-B operating in flight plan B
engines
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(1) December 31, 2001................ 23,200 cycles-since new (CSN) 19,700 CSN.
(2) December 31, 2002................ 22,500 cycles-since-new (CSN) 19,000 CSN.
(3) December 31, 2003................ 21,500 CSN................... 18,000 CSN.
(4) December 31, 2004................ 20,000 CSN................... 16,500 CSN.
(5) December 31, 2005................ 18,100 CSN................... 14,600 CSN.
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RB211-535E4 Engines Operating to Flight Plan A, and RB211-535E4-B
Engines
(b) For RB211-535E4 engines operating to flight plan A, and
RB211-535E4-B engines, remove the LP turbine stage 2 disc from
service using the CSN and Action times listed in the following Table
2.
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Table 2.--Drawdown Schedule for RB211-535E4 Engines Operating to Flight Plan A and RB211-535E4-B Engines
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Replace disc
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Disc CSN Action Without eddy current With eddy current
inspection inspection
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(1) 20,001 CSN or greater on December Remove disc from Within 21 days after Within 3,000 cycles-in-
31, 2000. service or perform the effective date of service (CIS) after
optional on-wing eddy this AD. the inspection, but do
current disc not exceed the new
inspection within 21 reduced life limit
days after the specified in Table 1
effective date of this of this AD.
AD.
(2) 18,100 to 20,000 CSN on December Remove disc from Before accumulating Within 3,000 CIS after
31, 2000. service or perform 21,000 CSN or within the inspection, but do
optional on-wing eddy 21 days after the not exceed the new
current disc effective date of this reduced life limit
inspection. AD, whichever occurs specified in Table 1
first. of this AD.
(3) Fewer than 18,100 CSN on December Remove disc from Before accumulating Within 3,000 CIS after
31, 2000 and greater than 20,000 CSN service or perform 20,500 CSN or by the inspection, but do
on December 31, 2004. optional on-wing eddy December 31, 2004, not exceed the new
current disc whichever occurs first. reduced life limit
inspection. specified in Table 1
of this AD.
(4) Fewer than 18,100 CSN on December Remove disc from Before accumulating Within 3,000 CIS after
31, 2000 and greater than 18,100 CSN service or perform on- 20,000 CSN or by the inspection, but do
on December 31, 2005. wing eddy current disc December 31, 2005, not exceed the new
inspection. whichever occurs first. reduced life limit
specified in Table 1
of this AD.
(5) Fewer than 18,100 CSN on December No action required..... N/A.................... N/A
31, 2000 and fewer than 18,100 CSN
on December 31, 2005.
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(c) Information regarding disc removal may be found in 3.A. of
the Accomplishment Instructions of Mandatory Service Bulletin (MSB)
RB.211-72-D181, Revision 3, dated August 16, 2002.
(d) The optional on-wing eddy current disc inspection noted in
Table 2 of this AD must be performed in accordance with 3.C.(1)
through 3.C.(6) of the Accomplishment Instructions of MSB RB.211-72-
D181, Revision 3, dated August 16, 2002.
RB211-535E4 Engines Operating to Flight Plan B
(e) For RB211-535E4 engines operating to flight plan B, remove
the LP turbine stage 2 disc from service using the CSN and Action
times listed in the following Table 3.
Table 3.--Drawdown Schedule for RB211-535E4 Engines Operating to Flight Plan B
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Replace disc
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Disc CSN Action Without eddy current With eddy current
inspection inspection
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(1) 16,501 CSN or greater on December Remove disc from Within 21 days after Within 3,000 CIS after
31, 2000. service or perform the effective date of the inspection, but do
optional on-wing eddy this AD. not exceed the new
current disc reduced life limit
inspection within 21 specified in Table 1
days after the of this AD.
effective date of this
AD.
(2) Greater than 14,600 CSN on Remove disc from Before accumulating Within 3,000 CIS after
December 31, 2000. service or perform 17,500 CSN or within the inspection, but do
optional on-wing eddy 21 days after the not exceed the new
current disc effective date of this reduced life limit
inspection. AD, whichever occurs specified in Table 1
first. of this AD.
(3) Fewer than 14,600 CSN on December Remove disc from Before accumulating Within 3,000 CIS after
31, 2000 and greater than 16,500 CSN service or perform 17,000 CSN or by the inspection, but do
on December 31, 2004. optional on-wing eddy December 31, 2004, not exceed the new
current disc whichever occurs first. reduced life limit
inspection. specified in Table 1
of this AD.
(4) Fewer than 14,600 CSN on December Remove disc from Before accumulating Within 3,000 CIS after
31, 2000 and greater than 14,600 CSN service or perform on- 16,500 CSN or by the inspection, but do
on December 31, 2005. wing eddy current disc December 31, 2005, not exceed the new
inspection. whichever occurs first. reduced life limit
specified in Table 1
of this AD.
(5) Fewer than 14,600 CSN on December No action required..... NA..................... NA.
31, 2000 and fewer than 14,600 CSN
on December 31, 2005.
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(f) Information regarding disc removal may be found in 3.A. of
the Accomplishment Instructions of MSB RB.211-72-D181, Revision 3,
dated August 16, 2002.
(g) The optional on-wing eddy current disc inspection must be
performed in accordance with 3.C.(1) through 3.C.(6) of the
Accomplishment Instructions of MSB RB.211-72-D181, Revision 3, dated
August 16, 2002.
Note 2: For engines moving from Flight Plans A to B or B to A,
the intermix calculations found in MSB RB.211-72-D181, Revision 3,
dated August 16, 2002, may be applied to the life limits.
Alternative Methods of Compliance
(h) 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, ECO. Operators must submit their
request through an appropriate FAA Principal Maintenance
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Inspector, who may add comments and then send it to the Manager,
ECO.
Note 3: Information concerning the existence of approved
alternative methods of compliance with this airworthiness directive,
if any, may be obtained from the Engine Certification Office (ECO).
Special Flight Permits
(i) Special flight permits may be issued in accordance with
Sec. Sec. 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 done.
Note 4:
The subject of this AD is addressed in CAA airworthiness
directive 006-05-2001, dated August 3, 2001.
Issued in Burlington, Massachusetts, on March 19, 2003.
Peter A. White,
Acting Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. 03-7004 Filed 3-24-03; 8:45 am]
BILLING CODE 4910-13-P