[Federal Register Volume 68, Number 57 (Tuesday, March 25, 2003)]
[Proposed Rules]
[Pages 14355-14359]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-7004]


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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: [email protected]. 
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
                                                               -------------------------------------------------
               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
                                                               -------------------------------------------------
               Disc CSN                         Action            Without eddy current      With eddy current
                                                                       inspection               inspection
----------------------------------------------------------------------------------------------------------------
(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

[[Page 14359]]

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