[Federal Register: June 25, 2004 (Volume 69, Number 122)]
[Rules and Regulations]
[Page 35508-35511]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr25jn04-3]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 2002-NE-19-AD; Amendment 39-13693; AD 2004-13-11]
RIN 2120-AA64
Airworthiness Directives; Rolls-Royce plc RB211 Trent 875-17,
Trent 877-17, Trent 884-17, Trent 884B-17, Trent 892-17, Trent 892B-17,
and Trent 895-17 Series Turbofan Engines
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for
Rolls-Royce plc (RR) RB211 Trent 875-17,
[[Page 35509]]
Trent 877-17, Trent 884-17, Trent 892-17, Trent 892B-17, and Trent 895-
17 series turbofan engines that have not incorporated RR Service
Bulletin (SB) No. RB.211-72-D495, dated February 7, 2003. This AD
requires initial and repetitive visual inspections or ultrasonic
inspections of the intermediate pressure (IP) compressor rear stubshaft
and IP turbine shaft for load-bearing spline flank wear, and
replacement of these shafts if necessary. This AD results from reports
of load-bearing spline flank wear of the IP compressor rear stubshaft
and IP turbine shaft, revealed at inspection during overhaul. We are
issuing this AD to prevent the loss of drive between the IP turbine and
the IP compressor, which could result in a turbine rotor overspeed
condition, possible uncontained engine failure, and damage to the
airplane.
DATES: This AD becomes effective July 30, 2004.
ADDRESSES: You can get the service information identified in this AD
from Rolls-Royce plc, P.O. Box 31 Derby, DE24 8BJ, United Kingdom;
telephone 011-44-1332-242424; fax 011-44-1332-249936.
You may examine the AD docket at the FAA, New England Region,
Office of the Regional Counsel, 12 New England Executive Park,
Burlington, MA.
FOR FURTHER INFORMATION CONTACT: Christopher Spinney, Aerospace
Engineer, Engine Certification Office, FAA, Engine and Propeller
Directorate, 12 New England Executive Park, Burlington, MA 01803-5299,
telephone (781) 238-7175; fax (781) 238-7199.
SUPPLEMENTARY INFORMATION: The FAA proposed to amend 14 CFR part 39
with a proposed airworthiness directive (AD). The proposed AD applies
to RR RB211 Trent 875-17, Trent 877-17, Trent 884-17, Trent 892-17,
Trent 892B-17, and Trent 895-17 series turbofan engines. We published
the proposed AD in the Federal Register on January 27, 2003 (68 FR
3836). That action proposed to require initial and repetitive visual
inspections for load-bearing spline flank wear of the IP compressor
rear stubshaft and IP turbine shaft, and replacement of these shafts if
necessary.
Comments
We provided the public the opportunity to participate in the
development of this AD. We have considered the comments received.
Request To Use an Alternate Ultrasonic Inspection
Three commenters request that we incorporate the intent of the
latest issue of RR Mandatory Service Bulletin (MSB) No. RB.211-72-D339,
Revision 1, dated March 28, 2003. The commenters ask that they be
allowed to use an alternate ultrasonic inspection of the IP compressor-
IP turbine shaft spline wear with a reduced repeat inspection time
interval, introduced by the revised MSB.
We agree. We have reviewed the latest revision of RR MSB No.
RB.211-72-D339, Revision 2, dated June 20, 2003, with RR and the Civil
Aviation Authority (CAA), which is the airworthiness authority for the
United Kingdom (U.K.), and we have approved the alternate ultrasonic
inspection in this AD. Also, because that MSB adds the Trent 884B-17
engine to the applicability, we have added that engine to this AD
applicability. We have concluded that since the proposal already
applies to the Trent 884-17, adding the Trent 884B-17 engine would not
require us to issue a supplemental notice of proposed rulemaking.
Currently, there are no Trent 884B-17 engines installed on airplanes of
U.S. registry.
Request To Change Compliance Intervals to Cycles Accumulated on
Component
One commenter requests that we change compliance intervals from
cycles accumulated on the engine, to cycles accumulated on the
component. The commenter states that components are sometimes switched
between engines, making cycle counting difficult.
We agree. Cycle counting on the component is a more precise way to
set the inspection intervals and is introduced in this proposal. Also,
this AD corrects an error in the NPRM where the initial inspection
interval was 4,500 cycles from the effective date of the AD, and should
have been 4,500 cycles-since-new (CSN).
Initial Inspection Drawdown Added
We have added an initial inspection drawdown of 100 cycles for
engines that have not had an initial inspection, but are over the
initial inspection threshold. We are not aware of any engines over the
initial threshold and that have not had the initial inspection.
Clarification of Engine Applicability
We have clarified the wording in the engine applicability, to state
that the AD applies to engines that have not incorporated RR SB No.
RB.211-72-D495, dated February 7, 2003. That SB incorporates a
modification for positive lubrication of the IP compressor rear
stubshaft and IP turbine shaft.
Conclusion
We have carefully reviewed the available data, including the
comments received, and determined that air safety and the public
interest require adopting the AD with the changes described previously.
We have determined that these changes will neither increase the
economic burden on any operator nor increase the scope of the AD. The
assigned paragraph letters in the regulatory section have been changed
from what appeared in the proposal, as we are continuing our
introduction of plain language into our documents.
Costs of Compliance
There are about 350 RR RB211 Trent 875-17, Trent 877-17, Trent 884-
17, Trent 892-17, Trent 892B-17, and Trent 895-17 series turbofan
engines of the affected design in the worldwide fleet. We estimate that
90 engines installed on airplanes of U.S. registry would be affected by
this AD. We also estimate that it would take about 0.5 work hours per
engine to perform the proposed inspections, and that the average labor
rate is $65 per work hour. Based on these figures, we estimate the
total cost to U.S. operators for performing one inspection to be
$2,925.
Regulatory Findings
We have determined that this AD will not have federalism
implications under Executive Order 13132. This AD will 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.
For the reasons discussed above, I certify that this AD:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866;
(2) Is not a ``significant rule'' under DOT Regulatory Policies and
Procedures (44 FR 11034, February 26, 1979); and
(3) 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.
We prepared a summary of the costs to comply with this AD and
placed it in the AD Docket. You may get a copy of this summary by
sending a request to us at the address listed under ADDRESSES. Include
``AD Docket No. 2002-NE-19-AD'' in your request.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
[[Page 35510]]
Adoption of the Amendment
0
Accordingly, under the authority delegated to me by the Administrator,
the Federal Aviation Administration amends 14 CFR part 39 as follows:
PART 39--AIRWORTHINESS DIRECTIVES
0
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]
0
2. The FAA amends Sec. 39.13 by adding the following new airworthiness
directive (AD):
2004-13-11 Rolls-Royce plc: Amendment 39-13693. Docket No. 2002-NE-
19-AD.
Effective Date
(a) This AD becomes effective July 30, 2004.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Rolls-Royce plc (RR) RB211 Trent 875-17,
Trent 877-17, Trent 884-17, Trent 892-17, Trent 892B-17, and Trent
895-17 series turbofan engines that have not incorporated RR SB No.
RB.211-72-D495, dated February 7, 2003. These engines are installed
on, but not limited to, Boeing 777 series airplanes.
Unsafe Condition
(d) This AD results from reports of load-bearing spline flank
wear of intermediate pressure (IP) compressor rear stubshaft and
intermediate pressure (IP) turbine shaft, revealed at inspection
during overhaul. We are issuing this AD to prevent the loss of drive
between the IP turbine and the IP compressor, which could result in
a turbine rotor overspeed condition, possible uncontained engine
failure, and damage to the airplane.
Compliance
(e) You are responsible for having the actions required by this
AD performed within the compliance times specified unless the
actions have already been done.
Initial Visual Inspection of the IP Turbine Shaft and IP Compressor
Stubshaft
(f) At the next accessibility of the IP turbine shaft, not to
exceed the later of 4,500 cycles-since-new (CSN) or 100 cycles after
the effective date of this AD on the IP turbine shaft, do the
following:
(1) Inspect the IP turbine shaft splines for wear. Information
on inspecting IP turbine shaft splines can be found in RR Mandatory
Service Bulletin (MSB) No. RB.211-72-D339, Revision 2, dated June
20, 2003.
(2) If the IP turbine shaft spline wear measured in paragraph
(f)(1) of this AD is greater than 0.005 inch, remove the IP turbine
shaft from service.
(3) If the IP turbine shaft spline wear measured in paragraph
(f)(1) of this AD is greater than 0.001 inch, inspect IP compressor
stubshaft splines for wear. Information on inspecting IP compressor
stubshaft splines can be found in RR MSB No. RB.211-72-D339,
Revision 2, dated June 20, 2003.
(4) If the IP compressor stubshaft spline wear measured in
paragraph (f)(3) of this AD is greater than 0.005 inch, remove the
IP compressor stubshaft from service.
(5) For the purposes of this AD, accessibility of the IP turbine
shaft is defined as removal of the IP turbine module from the
engine.
Repetitive Visual Inspections of the IP Turbine Shaft and IP Compressor
Stubshaft
(g) Perform repetitive visual inspections of the IP turbine
shaft and IP compressor stubshaft using the procedures specified in
paragraph (f)(1) through (f)(4) of this AD, at each accessibility,
not to exceed the applicable repetitive inspection intervals in the
following Table 1:
Table 1.--Repetitive Visual Inspection Intervals
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Results of last inspection Reinspection interval
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(1) If wear was less than 0.001 inch on Reinspect within 4,500 cycles-
IPT shaft splines and IPC stubshaft since-last visual inspection
splines. (CSLI) of the IPT shaft
splines.
(2) If wear was 0.001 inch or greater Reinspect within 2,000 CSLI of
on IPT shaft splines or on the IPC the IPT shaft splines or IPC
stubshaft splines. stubshaft, whichever occurs
first.
(3) If an ultrasonic measurement of Reinspect within 3,000 cycles
wear was less than 0.013 inch. since last ultrasonic
inspection.
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Optional Initial Ultrasonic Inspection of the IPT Shaft and IPC
Stubshaft
(h) As an option to the initial visual inspection specified in
paragraph (f) of this AD, do the following:
(1) At the later of 4,400 CSN or 100 cycles after the effective
date of this AD on the IPT shaft, ultrasonically inspect the IP
compressor stubshaft. Information on the ultrasonic inspection can
be found in RR MSB No. RB.211-72-D339, Revision 2, dated June 20,
2003.
(2) If wear is greater than 0.013 inch, remove engine from
service within an additional 100 cycles-in-service.
Optional Repetitive Ultrasonic Inspections of the IP Turbine Shaft and
IP Compressor Stubshaft
(i) As an option to the repetitive visual inspections specified
in paragraph (g) of this AD, do the following:
(1) Ultrasonically inspect the IP compressor stubshaft, using
the repetitive inspection intervals in Table 2 of this AD.
Information on the ultrasonic inspection can be found in RR MSB No.
RB.211-72-D339, Revision 2, dated June 20, 2003.
Table 2.--Repetitive Ultrasonic Inspection Intervals
------------------------------------------------------------------------
Results of last inspection Reinspection interval
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(i) If visually inspected wear was less Reinspect within 4,400 cycles-
than 0.001 inch on IPT shaft splines since-last visual inspection
and IPC stubshaft splines. (CSLVI) of the IPT shaft
splines.
(ii) If visually inspected wear was Reinspect within 2,000 CSLVI of
0.001 inch or greater on IPT shaft the IPT shaft splines or IPC
splines or on the IPC stubshaft stubshaft, whichever occurs
splines. first.
(iii) If ultrasonically inspected wear Reinspect within 3,000 since
was less than 0.013 inch. last ultrasonic inspection.
------------------------------------------------------------------------
(2) If wear is greater than 0.013 inch, remove engine from
service within an additional 100 cycles-in-service.
Alternative Methods of Compliance
(j) The Manager, Engine Certification Office, has the authority
to approve alternative methods of compliance for this AD if
requested using the procedures found in 14 CFR 39.19.
Material Incorporated by Reference
(k) None.
[[Page 35511]]
Related Information
(l) Rolls-Royce plc MSB No. RB.211-72-D339, Revision 2, dated
June 20, 2003, pertains to the subject of this AD.
Issued in Burlington, Massachusetts, on June 18, 2004.
Francis A. Favara,
Acting Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. 04-14317 Filed 6-24-04; 8:45 am]
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