[Federal Register Volume 69, Number 247 (Monday, December 27, 2004)]
[Proposed Rules]
[Pages 77144-77146]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-28145]


 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
 
 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
 ========================================================================
 

  Federal Register / Vol. 69, No. 247 / Monday, December 27, 2004 / 
Proposed Rules  

[[Page 77144]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2004-19930; Directorate Identifier 2004-NE-33-AD]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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

SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for Rolls-Royce plc (RR) RB211 Trent 800 series turbofan engines. This 
proposed AD would require initial and repetitive borescope inspections 
of the high pressure-and-intermediate pressure (HP-IP) turbine internal 
and external oil vent tubes for coking and carbon buildup, and cleaning 
or replacing the vent tubes if necessary. This proposed AD results from 
a report of an RB211 Trent 700 series engine experiencing a disk shaft 
separation, overspeed of the IP turbine rotor, and multiple blade 
release of IP turbine blades. Preliminary findings suggest these events 
resulted from an internal oil fire in the HP-IP turbine oil vent tubes 
due to coking and carbon buildup. This fire led to a second fire in the 
internal air cavity below the IP turbine disk drive shaft. We are 
proposing this AD to prevent internal oil fires in RB211 Trent 800 
series turbofan engines due to coking and carbon buildup, that could 
cause uncontained engine failure and damage to the airplane.

DATES: We must receive any comments on this proposed AD by February 25, 
2005.

ADDRESSES: Use one of the following addresses to comment on this 
proposed AD.
     DOT Docket Web Site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide Rulemaking Web Site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility; U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, 
Washington, DC 20590-001.
     Fax: (202) 493-2251.
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    Contact Rolls-Royce plc, PO Box 31, Derby, England; telephone: 011-
44-1332-249428; fax: 011-44-1332-249223 for the service information 
identified in this proposed AD.

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

    We invite you to submit any written relevant data, views, or 
arguments regarding this proposal. Send your comments to an address 
listed under ADDRESSES. Include ``Docket No. FAA-2004-19930; 
Directorate Identifier 2004-NE-33-AD'' in the subject line of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments received by the closing date and may amend the 
proposed AD in light of those comments.
    We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this proposed AD. Using the search function of the 
DMS Web site, anyone can find and read the comments in any of our 
dockets, including the name of the individual who sent the comment (or 
signed the comment on behalf of an association, business, labor union, 
etc.). You may review the DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78) or you 
may visit http://dms.dot.gov.

Examining the AD Docket

    You may examine the docket that contains the proposal, any comments 
received, and any final disposition in person at the DMS Docket Offices 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Office (telephone (800) 647-5227) is on the plaza 
level of the Department of Transportation Nassif Building at the street 
address stated in ADDRESSES. Comments will be available in the AD 
docket shortly after the DMS receives them.

Discussion

    As a member of the National Transportation Safety Board (NTSB) 
investigation team, we are investigating an incident event on RR RB211 
Trent 700 series engines and possible unsafe condition on RB211 Trent 
800 series engines. The Civil Aviation Authority (CAA), which is the 
airworthiness authority for the United Kingdom (UK) is helping us 
investigate. A report was received of an RB211 Trent 700 series engine 
experiencing a disk shaft separation, overspeed of the IP turbine 
rotor, and multiple blade release of IP turbine blades. Preliminary 
findings suggest these events resulted from an internal oil fire in the 
HP-IP turbine oil vent tubes due to coking and carbon buildup. This 
fire led to a second fire in the internal air cavity below the IP 
turbine disk drive shaft. Because the oil vent tubes on the event 
engine were destroyed, the partner engine on the same airplane was 
inspected. That inspection revealed heavy coking and carbon buildup, 
with partial blockage of the HP-IP turbine oil vent tubes. Both engines 
had the same on-wing life of 15,169 hours with 2,344 cycles-since-new. 
Both engines contained Mobil Jet Oil 291, which also is suspect and 
will be removed from the list of approved oils for these engines. The 
NTSB investigation is ongoing and a probable cause finding has not yet 
been made. The fire, disk overspeed, and blade release appear to be the 
result of the coking and carbon buildup, evident in the sister engine 
and linked by cycles and oil use to the event engine. The Trent 800 
series engines have similar

[[Page 77145]]

design HP-IP turbine oil vent tubes and are the subject of this 
proposed AD.

Relevant Service Information

    We have reviewed and approved the technical contents of RR Alert 
Service Bulletin (ASB) No. RB.211-72-AE362, dated May 7, 2004, that 
describes procedures for:
     Initial and repetitive borescope inspections for coking 
and carbon buildup in the HP-IP turbine oil vent tubes; and
     Cleaning the tubes if necessary, and removing the engine 
from service to clean or replace the tubes.
    This ASB requires that all operators submit inspection data to the 
manufacturer. The CAA classified this ASB as mandatory and issued AD G-
2004-0009, dated May 27, 2004, in order to ensure the airworthiness of 
these RB211 Trent 800 series engines in the UK.

Differences Between This Proposed AD and the Manufacturer's Service 
Information

    Although RR ASB No. RB.211-72-AE362, dated May 7, 2004, requires 
replacing the scavenge oil filter and sending the removed filter to RR 
for examination as part of returning the engine to service, this 
proposed AD does not require sending the removed filter to RR.

FAA's Determination and Requirements of the Proposed AD

    These Trent 800 series engines, manufactured in the U.K., are 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. In keeping with this 
bilateral airworthiness agreement, the CAA kept us informed of the 
situation described above. We have examined the CAA's findings, 
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. For this reason, we are proposing this 
AD, which would require:
     Initial and repetitive borescope inspections of the HP-IP 
turbine oil vent tubes for coking and carbon buildup; and
     Cleaning the oil vent tubes or removing the engine from 
service if the tubes fail the inspection.

Interim Action

    These actions are interim actions and we may take further 
rulemaking actions in the future.

Costs of Compliance

    There are about 420 RB211 Trent 800 series engines of the affected 
design in the worldwide fleet. We estimate that this proposed AD would 
affect 120 engines installed on airplanes of U.S. registry. We also 
estimate that it would take about 1.5 work hours per engine to perform 
the proposed on-wing inspections, and about 0.5 work hour to perform 
the proposed in-shop inspections. The average labor rate is $65 per 
work hour. Based on these figures, we estimate the total cost for U.S. 
operators to perform one on-wing inspection to be $11,700, and the 
total cost to perform one in-shop inspection to be $3,900.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, Section 106, describes the 
authority of the FAA Administrator. Subtitle VII, Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701, ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    We have determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD 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.
    For the reasons discussed above, I certify that the 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. Would 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 proposal and 
placed it in the AD Docket. You may get a copy of this summary at the 
address listed under ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Under the authority delegated to me by the Administrator, the 
Federal Aviation Administration proposes to amend 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. The FAA amends Sec.  39.13 by adding the following new 
airworthiness directive:

Rolls-Royce plc: Docket No. FAA-2004-19930; Directorate Identifier 
2004-NE-33-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive comments 
on this airworthiness directive (AD) action by February 25, 2005.

Affected ADs

    (b) None.
    Applicability: (c) This AD applies to Rolls-Royce plc (RR) RB211 
Trent 875-17, 877-17, 884-17, 884B-17, 892-17, 892B-17, and 895-17 
series turbofan engines. These engines are installed on, but not 
limited to, Boeing 777 airplanes.

Unsafe Condition

    (d) This AD results from a report of an RB211 Trent 700 series 
engine experiencing a disk shaft separation, overspeed of the IP 
turbine rotor, and multiple blade release of IP turbine blades. 
Preliminary findings suggest these events resulted from an internal oil 
fire in the HP-IP turbine oil vent tubes due to coking and carbon 
buildup. This fire led to a second fire in the internal air cavity 
below the IP turbine disk drive shaft. We are issuing this AD to 
prevent internal oil fires in RB211 Trent 800 series turbofan engines 
due to coking and carbon buildup, that could cause 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.

[[Page 77146]]

Initial Visual Inspection

    (f) Using paragraph 3.A. (on-wing) or 3.B. (in-shop) of 
Accomplishment Instructions of RR Alert Service Bulletin (ASB) RB.211-
72-AE362, dated May 7, 2004, and the inspection schedule in Table 1 of 
this AD, perform an initial borescope inspection of the high pressure-
and-intermediate pressure (HP-IP) turbine internal and external oil 
vent tubes for coking and carbon buildup as follows:
    (1) Insert an 8 mm diameter flex borescope to see if it will pass 
along the full length of the vent tube into the bearing chamber.
    (2) If the vent tube prevents an 8 mm diameter flex borescope from 
passing along the full length of the tube into the bearing chamber, 
repeat the action using a 6 mm flex borescope.
    (3) If the 6 mm diameter flex borescope passes through to the 
bearing chamber, continue using the engine in service, and perform the 
repetitive inspections in this AD at the required intervals specified 
in Table 2 of this AD.
    (4) If the vent tube prevents the 6 mm diameter flex borescope from 
passing along the full length of the tube into the bearing chamber, 
remove the engine from service within 10 cycles-since-last inspection 
(CSLI).

                  Table 1.--Initial Inspection Schedule
------------------------------------------------------------------------
    If the engine or the 05 module:          Then initially inspect:
------------------------------------------------------------------------
Has reached the threshold life of        Within 1,000 hours time-in-
 15,000 hours time-since new (TSN) or     service (TIS) or 200 cycles-in
 reached the threshold life of 3,000      service (CIS) after the
 cycles-since-new (CSN) on the            effective date of this AD,
 effective date of this AD.               whichever occurs first.
Has fewer than 15,000 hours TSN or       Within 1,000 hours TIS or 200
 fewer than 3,000 CSN on the effective    CIS after reaching the
 date of this AD.                         threshold life.
------------------------------------------------------------------------

Repetitive Visual Inspections

    (g) Using paragraph 3.A. (on-wing) or 3.B. (in-shop) of 
Accomplishment Instructions of RR ASB RB.211-72-AE362, dated May 7, 
2004, paragraphs (f)(1) through (f)(4) of this AD, and the inspection 
schedule in Table 2 of this AD, perform repetitive borescope 
inspections of the HP-IP turbine internal and external oil vent tubes 
for coking and carbon buildup.

                Table 2.--Repetitive Inspection Schedule
------------------------------------------------------------------------
 If at the previous inspection, before
      any cleaning was performed:                     Then:
------------------------------------------------------------------------
(1) There was no coking and carbon       Reinspect within 6,000 hours
 buildup of a visible thickness; or an    time-since-last-inspection
 8 mm diameter flex borescope could       (TSLI) or within 1,200 cycles-
 pass along the full length of the        since-last-inspection (CSLI),
 internal vent tube into the bearing      whichever occurs first.
 chamber.
(2) The coking or carbon buildup         Reinspect within 1,500 hours
 prevented an 8 mm diameter flex          TSLI or within 300 CSLI,
 borescope from passing through the       whichever occurs first.
 internal vent tube, but a 6 mm
 diameter flex borescope could pass
 along the full length of the internal
 vent tube into the bearing chamber.
(3) The coking or carbon buildup         Remove the engine from service
 prevented the 6 mm diameter flex         within 10 CSLI.
 borescope from passing through the
 full length of the internal vent tube
 and into the bearing chamber.
------------------------------------------------------------------------

Reporting Requirements

    (h) Report findings of the inspection to Rolls-Royce using Table 1 
(On-wing Inspection Findings) or Table 2 (In-shop Inspection Findings) 
of RR ASB RB.211-72-AE362, dated May 7, 2004. The Office of Management 
and Budget (OMB) has approved the reporting requirements specified in 
Table 1 and Table 2 of RR ASB RB.211-72-AE362, dated May 7, 2004, and 
assigned OMB control number 2120-0056.

Alternative Methods of Compliance

    (i) 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.

Related Information

    (j) CAA airworthiness directive No. G-2004-0009, dated May 27, 
2004, also addresses the subject of this AD.

    Issued in Burlington, Massachusetts, on December 17, 2004.
Francis A. Favara,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 04-28145 Filed 12-23-04; 8:45 am]
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