AD 2001-26-11

[Federal Register Volume 66, Number 250 (Monday, December 31, 2001)]
[Rules and Regulations]
[Pages 67477-67479]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 01-31699]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-ANE-33-AD; Amendment 39-12575; AD 2001-26-11]
RIN 2120-AA64


Airworthiness Directives; Rolls-Royce, plc RB211 Trent 800 Series 
Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD) that is applicable to Rolls-Royce, plc RB211 Trent 800 series 
turbofan engines. That AD currently requires initial and repetitive 
ultrasonic inspections of low pressure compressor (LPC) fan blade roots 
for cracks, and replacement, if necessary, with serviceable parts. This 
amendment requires initial inspections at modified thresholds and 
repetitive inspections at reduced intervals from the current AD using 
new LPC fan blade inspection criteria, and requires renewal of dry film 
lubricant on removed blades. This amendment is prompted by reports that 
an in-service engine experienced LPC fan blade root cracking at a lower 
life than previously forecast, and, the manufacturer's further 
investigation that has led to a better understanding of the causes of 
fan blade root cracking. The actions specified in this AD are intended 
to prevent LPC fan blade failure due to cracking, which could result in 
multiple fan blade release, uncontained engine failure, and possible 
damage to the airplane.

DATES: Effective January 30, 2002. The incorporation by reference of 
certain publications listed in the rule is approved by the Director of 
the Federal Register as of January 30, 2002.
    Comments for inclusion in the Rules Docket must be received on or 
before March 1, 2002.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), New England Region, Office of the Regional 
Counsel, Attention: Rules Docket No. 98-ANE-33-AD, 12 New England 
Executive Park, Burlington, MA 01803-5299. Comments may be inspected at 
this location, by appointment, 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: ``<a href="/cdn-cgi/l/email-protection#7f46521e111a521e1b1c1012121a110b3f191e1e51181009"><span class="__cf_email__" data-cfemail="8ab3a7ebe4efa7ebeee9e5e7e7efe4fecaecebeba4ede5fc">[email&#160;protected]</span></a>''. 
Comments sent via the Internet must contain the docket number in the 
subject line. The service information referenced in this AD may be 
obtained from Rolls-Royce plc, Technical Publications Department, PO 
Box 31, Derby, England DE248BJ; telephone 44 1332 242424, fax, 1332 
249936. This information may be examined, by appointment, at the FAA, 
New England Region, Office of the Regional Counsel, 12 New England 
Executive Park, Burlington, MA; or at the Office of the Federal 
Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Keith Mead, Aerospace Engineer, Engine 
Certification Office, FAA, Engine and Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803-5299; telephone (781) 238-
7744; fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: On November 30, 2000, the Federal Aviation 
Administration (FAA) issued airworthiness directive (AD) 2000-24-26, 
Amendment 39-12033 (65 FR 77778, December 13, 2000), applicable to 
Rolls-Royce, plc RB211 Trent 875, RB211 Trent 877, RB211 Trent 884, 
RB211 Trent 892, and RB211 Trent 892B series turbofan engines, to 
require initial and repetitive ultrasonic inspections of low pressure 
compressor (LPC) fan blade roots for cracks, and replacement, if 
necessary, with serviceable parts. This AD requires initial inspections 
at modified thresholds and repetitive

[[Page 67478]]

inspections at reduced intervals from the current AD using new LPC fan 
blade inspection criteria, and requires renewal of dry film lubricant 
on removed blades.
    Since AD 2000-24-26 was issued, the Civil Aviation Authority (CAA), 
which is the airworthiness authority for the United Kingdom (UK), 
advises that an in-service engine experienced LPC fan blade root 
cracking at a lower life than previously forecast. The manufacturer's 
analysis of this new event has produced an improved understanding of 
the relationship between engine climb and takeoff speeds, and their 
effect on the crack initiation mechanism. These changes are the result 
of an improved understanding of the crack propagation mechanism and the 
latest service operational data.

Manufacturer's Service Information

    Rolls-Royce, plc has issued Service Bulletin (SB) No. RB.211-72-
C445, Revision 7, dated May 10, 2001, that specifies initial 
inspections at modified thresholds and repetitive inspections at 
reduced intervals from the current AD using new LPC fan blade 
inspection criteria, and requires renewal of dry film lubricant on 
removed blades. The CAA classified this service bulletin as mandatory 
and issued AD 003-04-98, dated May 10, 2001, in order to assure the 
airworthiness of these Rolls-Royce, plc engines in the UK.

Bilateral Airworthiness Agreement

    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.

FAA's Determination of an Unsafe Condition and Required Actions

    Although none of these affected engine models are used on any 
airplanes that are registered in the United States, the possibility 
exists that the engine models could be used on airplanes that are 
registered in the United States in the future. Since an unsafe 
condition has been identified that is likely to exist or develop on 
other Rolls-Royce, plc RB211 Trent 875, RB211 Trent 877, RB211 Trent 
884, RB211 Trent 892, and RB211 Trent 892B series turbofan engines of 
the same type design, this AD is being issued to prevent LPC fan blade 
failure, which could result in multiple fan blade release, uncontained 
engine failure, and possible damage to the airplane. This AD requires 
initial inspections at modified thresholds and repetitive inspections 
at reduced intervals from the current AD using new LPC fan blade 
inspection criteria, and requires renewal of dry film lubricant on 
removed blades. The actions are required to be done in accordance with 
the service bulletin described previously.

Immediate Adoption of This AD

    Since there are currently no domestic operators of this engine 
model, notice and opportunity for prior public comment are unnecessary. 
Therefore, a situation exists that allows the immediate adoption of 
this regulation.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the rule. All comments submitted will be 
available, both before and after the closing date for comments, in the 
Rules Docket for examination, by appointment, by interested persons. A 
report that summarizes each FAA-public contact concerned with the 
substance of this AD 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 98-ANE-33-AD.'' The postcard will be date stamped and 
returned to the commenter.

Regulatory Analysis

    This final 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 final rule.
    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 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 final evaluation has been prepared for 
this action and it 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, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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 39-12033 (65 FR 
77778 December 13, 2000) and by adding a new airworthiness directive, 
Amendment 39-12575, to read as follows:

2001-26-11  Rolls-Royce, plc: Amendment 39-12575. Docket No. 98-ANE-
33-AD. Supersedes AD 2000-24-26, Amendment 39-12033.

Applicability

    This airworthiness directive (AD) is applicable to Rolls-Royce 
plc (RR) RB211 Trent 875, RB211 Trent 877, RB211 Trent

[[Page 67479]]

884, RB211 Trent 892, and RB211 Trent 892B series turbofan engines, 
with low pressure compressor (LPC) fan blades, part numbers (P/N's) 
FK23750, FK25975, FK25548, or FK26757 installed. These engines are 
installed on, but not limited to Boeing 777 series airplanes.

    Note 1: This 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 (i) 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 LPC fan blade failure due to cracking, which could 
result in multiple fan blade release, uncontained engine failure, 
and possible damage to the airplane, do the following:

Initial Inspection

    (a) Ultrasonically inspect the dovetail roots of LPC fan blades 
for cracks, in accordance with Appendix 1 (Method A) of RR Service 
Bulletin (SB) RB.211-72-C445, Revision 7, dated May 10, 2001, at the 
Initial Inspection Threshold cyclic times listed in the following 
Table 1 of this AD:

                                          Table 1.--Inspection Schedule
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                                                                                    Inspection
                                                                      Initial       intervals,
                                                                    inspection     cycles-since-     Part life
                      Engine model (rating)                         threshold,         last       threshold, CSN
                                                                   cycles-since-    inspection
                                                                     new (CSN)        (CSLI)
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(1) Trent 875...................................................           3,000             400           4,200
(2) Trent 877...................................................           2,000             350           3,050
(3) Trent 884...................................................           1,500             350           2,200
(4) Trent 892 and Trent 892B....................................             900             200           1,300
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Dry Film Lubricant Renewal

    (b) Apply an approved dry film lubricant to LPC fan blade roots 
of blades inspected by Method A. Procedures for renewing the dry 
film lubricant on the blade roots are specified in the AMM task 72-
31-11-300-801-R00 (Repair Scheme FRS A031 by air spray method only) 
or engine manual 72-31-11-R001 (Repair Scheme FRS A028). For 
purposes of this AD, approved lubricants are Dow Corning 321R 
(Rolls-Royce (RR) Omat item 4/52), Rocol Dry Moly Spray (RR Omat 
item 4/52), Molydag 709 (RR Omat item 444), or PL.237/R1 (RR Omat 
item 4/43).

Repetitive Inspections

    (c) Except for the first inspection after exceeding the Part 
Life Threshold listed in Table 1 of this AD, ultrasonically inspect 
the dovetail roots of LPC fan blades for cracks and renew dry film 
lubricant when specified in accordance with Appendix 1 (Method A) or 
Appendix 2 (Method B) of RR SB RB.211-72-C445, Revision 7, dated May 
10, 2001, and the Inspection Intervals listed Table 1 of this AD.

First Inspection After Exceeding Part Life Threshold

    (d) For the first inspection after exceeding the Part Life 
Threshold listed in Table 1 of this AD, ultrasonically inspect the 
dovetail roots of LPC fan blades for cracks in accordance with 
Appendix 1 (Method A) of RR SB RB.211-72-C445, Revision 7, dated May 
10, 2001. Thereafter, the repetitive inspections may be done using 
either Appendix 1 (Method A) or Appendix 2 (Method B), as specified 
in paragraph (c) of this AD.

Fan Blades Exceeding Initial Inspection Threshold

    (e) For blades that have, on the effective date of the AD, more 
cycles since installation than the initial compliance criteria in 
Table 1, inspect blades within 100 cycles in service after the 
effective date of this AD.

Engine Rating Changes

    (f) For an engine that has changed its rating, inspect fan 
blades at the correct cycle time as follows:
    (1) From higher rating to lower rating, inspect fan blades 
before further flight, as specified in this AD and reinspect at the 
interval applicable to the lower rating.
    (2) From lower rating to higher rating, inspect fan blades at 
intervals applicable to the higher rating.

Method A Acceptance Criteria

    (g) For Method A, replace blades that do not meet the acceptance 
criteria in Appendix 1 of RR SB RB.211-72-C445, Revision 7, dated 
May 10, 2001.

Method B Acceptance Criteria

    (h) For Method B, for blades that do not meet the acceptance 
criteria in Appendix 2 of RR SB RB.211-72-C445, Revision 7, dated 
May 10, 2001, remove blades and ultrasonically inspect the dovetail 
roots for cracks in accordance with Appendix 1 (Method A) of RR SB 
RB.211-72-C445, Revision 7, dated May 10, 2001.

Alternative Methods of Compliance

    (i) 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 must submit their requests 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.

Special Flight Permits

    (j) 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 done.

Documents That Have Been Incorporated by Reference

    (k) The inspection must be done in accordance with Rolls-Royce 
plc Service Bulletin(SB) No. RB.211-72-C445, Revision 7, dated May 
10, 2001. This incorporation by reference was approved by the 
Director of the Federal Register in accordance with 5 U.S.C. 552(a) 
and 1 CFR part 51. Copies may be obtained from Rolls-Royce plc, 
Technical Publications Department, PO Box 31, Derby, England 
DE248BJ; telephone 44 1332 242424, fax, 1332 249936. Copies may be 
inspected, by appointment, at the FAA, New England Region, Office of 
the Regional Counsel, 12 New England Executive Park, Burlington, MA; 
or at the Office of the Federal Register, 800 North Capitol Street, 
NW., suite 700, Washington, DC.

    Note 3: The subject of this AD is addressed in Civil Aviation 
Authority airworthiness directive AD 003-04-98, issued on May 10, 
2001.

Effective Date

    (l) This amendment becomes effective on January 30, 2002.

    Issued in Burlington, Massachusetts, on December 17, 2001.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 01-31699 Filed 12-28-01; 8:45 am]
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