AD 2004-13-11

[Federal Register Volume 69, Number 122 (Friday, June 25, 2004)]
[Rules and Regulations]
[Pages 35508-35511]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 04-14317]


-----------------------------------------------------------------------

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.

-----------------------------------------------------------------------

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
------------------------------------------------------------------------
       Results of last inspection             Reinspection interval
------------------------------------------------------------------------
(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.
------------------------------------------------------------------------

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
------------------------------------------------------------------------
(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]
BILLING CODE 4910-13-P