E6-1092. Airworthiness Directives; Rolls-Royce plc RB211 Series Turbofan Engines

AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT).

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to supersede an existing airworthiness directive (AD) for Rolls-Royce plc (RR) models RB211-535E4-37, RB211-535E4-B-37, RB211-535C-37, RB211-535E4-B-75, RB211-535E4-C, and RB211-22B-02 turbofan engines. That AD currently requires inspecting certain high pressure (HP) turbine discs, manufactured between 1989 and 1999, for cracks in the rim cooling air holes, and, if necessary, replacing the discs with serviceable parts. This proposed AD would require the same inspections, and would reduce the compliance times for eddy current inspection (ECI) for the RR RB211-22B-02 engines. This proposed AD results from the manufacturer reducing their recommended compliance times for inspections on RB211-22B-02 engines. We are proposing this AD to prevent possible disc failure, which could result in an uncontained engine failure and damage to the airplane.

DATES:

We must receive any comments on this proposed AD by March 31, 2006.

ADDRESSES:

Use one of the following addresses to comment on this proposed AD:

• By mail: Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 2000-NE-62-AD, 12 New England Executive Park, Burlington, MA 01803-5299.
• By fax: [phone].
• By e-mail: [e-mail].

You can get the service information identified in this proposed AD from Rolls-Royce plc, PO Box 31, Derby, England; telephone: [phone], fax: [phone].

You may examine the AD docket, by appointment, 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 [phone], fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or arguments regarding this proposal. Send your comments to an address listed under ADDRESSES. Include “AD Docket No. 2000-NE-62-AD” in the subject line of your comments. If you want us to acknowledge receipt of your mailed comments, send us a self-addressed, stamped postcard with the docket number written on it; we will date-stamp your postcard and mail it back to you. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. If a person contacts us verbally, and that contact relates to a substantive part of this proposed AD, we will summarize the contact and place the summary in the docket. We will consider all comments received by the closing date and may amend the proposed AD in light of those comments.

Examining the AD Docket

You may examine the AD Docket (including any comments and service information), by appointment, between 8 a.m. and 4:30 p.m., Monday through Friday, except Federal holidays. See ADDRESSES for the location.

Discussion

On December 15, 2004, the FAA issued AD 2004-26-03, Amendment 39-13915 (69 FR 77881, December 29, 2004) for RR models RB211-535E4-37, RB211-535E4-B-37, RB211-535C-37, RB211-535E4-B-75, and RB211-22B-02 turbofan engines. That AD requires inspecting certain HP turbine discs, manufactured between 1989 and 1999, for cracks in the rim cooling air holes, and, if necessary, replacing the discs with serviceable parts.

Actions Since AD 2004-26-03 Was Issued

Since we issued AD 2004-26-03, the Civil Aviation Authority (CAA), which is the airworthiness authority for the United Kingdom, notified us that an unsafe condition might exist on RR model RB211-22B-02 turbofan engines manufactured between 1989 and 1999. The CAA advises that cracks were found in a Trent 800 HP turbine disc attributable to machining anomalies during new manufacture. The RB211-22B-02 HP turbine is similar in design to the Trent 800, manufactured at the same facility and with the same tooling. This proposed AD would require inspection of certain HP turbine discs, manufactured between 1989 and 1999, for cracks in the rim cooling air holes, and, if necessary, replacement with serviceable parts. We are reducing the inspection schedules required by AD 2004-26-03, for the high risk discs installed on model RB211-22B-02 engines. This AD retains the same inspection schedules, currently required for RR models RB211-535E4-37, RB211-535E4-B-37, RB211-535C-37, RB211-535E4-B-75 turbofan engines that were in AD 2004-26-03. The actions specified in this proposed AD are intended to prevent possible disc failure, which could result in an uncontained engine failure and damage to the airplane.

Bilateral Airworthiness Agreement

This engine model is manufactured in the United Kingdom 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. Under this bilateral airworthiness agreement, the CAA has kept the FAA informed of the situation described above. We have 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.

Relevant Service Information

We have reviewed and approved the technical contents of RR ASB RB.211-72-AE717, dated January 21, 2005, that describes procedures for inspecting the RB211-22B disk for cracks. The CAA classified this service bulletin as mandatory and issued AD G-2005-0003, dated January 24, 2005, in order to ensure the airworthiness of these RR RB211-22 turbofan engines in the U.K.

FAA's Determination and Requirements of the Proposed AD

We have evaluated all pertinent information and identified an unsafe condition that is likely to exist or develop on other products of this same type design. Therefore, we are proposing this AD, which would require the same inspections specified in AD 2004-26-03, but would reduce the compliance times for the model RB211-22B engine to:

• Within 500 cycles-in-service (CIS) after January 1, 2005 or before accumulating 11,000 cycles-since-new (CSN), whichever occurs first, on engines with more than 9,000 CSN on January 1, 2005, and
• Before accumulating 9,500 CSN or at the next shop visit after the effective date of this proposed AD, whichever occurs first, on engines with more than 1,500 CSN but fewer than 9,001 CSN on January 1, 2005.

The proposed AD would require that you do these actions using the service information described previously.

Costs of Compliance

We estimate that this proposed AD would affect six RR RB211-22B engines installed on airplanes of U.S. registry. We also estimate that it would take about 4.0 work hours per engine to perform the proposed actions, and that the average labor rate is $65 per work hour. There are no required parts. Based on these figures, we estimate the total cost of the proposed AD to U.S. operators to be $1,560.

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 by sending a request to us at the address listed under ADDRESSES. Include “AD Docket No. 2000-NE-62-AD” in your request.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

Accordingly, 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.

§ 39.13

[Amended]

2. The FAA amends § 39.13 by removing Amendment 39-13915 (69 FR 77881, December 29, 2004) and by adding a new airworthiness directive, to read as follows:

Rolls-Royce plc: Docket No. 2000-NE-62-AD.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by March 31, 2006.

Affected ADs

(b) This AD supersedes AD 2004-26-03, Amendment 39-13915.

Applicability

(c) This AD applies to Rolls-Royce plc (RR) models RB211-535E4-37, RB211-535E4-B-37, RB211-535C-37, RB211-535E4-B-75, RB211-535E4-C, and RB211-22B-02 turbofan engines with turbine discs having part numbers and serial numbers listed in the following Tables 1, 3, and 5 of this AD. These turbofan engines are installed on, but not limited to, Boeing 757, Tupolev Tu204, and Lockheed L-1011 series airplanes.

Unsafe Condition

(d) This AD results from the manufacturer reducing the inspection compliance times for the RB211-22B-02 turbofan engines. We are issuing this AD to prevent possible disc failure, which could result in an 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.

Eddy Current Inspection for All Except Model RB211-22B-02 Engines

(f) For all except model RB211-22B-02 engines, do the following:

(1) Perform an eddy current inspection of the high pressure (HP) turbine discs listed in Table 1 of this AD, for cracks in the rim cooling air holes. Use paragraph 3. of the Accomplishment Instructions of RR Alert Service Bulletin (ASB) No. RB.211-72-AE651, dated November 22, 2004, to perform the eddy current inspection.

Table 1.—Affected HP Turbine Discs Using Compliance Schedule in Table 2

Part No.	Serial No.	Part No.	Serial No.
LK80623	CQDY6397	UL27681	LDRCZ12893
LK80623	CQDY6504	UL27681	LDRCZ12985
UL27680	CQDY6451	UL27681	LDRCZ13044
UL27680	CQDY6452	UL27681	LDRCZ13047
UL27680	CQDY6466	UL27681	LQDY6803
UL27680	CQDY6468	UL27681	LQDY6814
UL27680	CQDY6471	UL27681	LQDY6847
UL27680	CQDY6496	UL27681	LQDY6868
UL27680	CQDY6505	UL27681	LQDY6875
UL27680	CQDY6653	UL27681	LQDY6892
UL27680	CQDY6656	UL27681	LQDY6898
UL27680	CQDY6657	UL27681	LQDY6904
UL27680	CQDY6684	UL27681	LQDY6909
UL27680	CQDY6883	UL27681	LQDY6910
UL27681	CQDY6465	UL27681	LQDY9133
UL27681	LAQDY6002	UL27681	LQDY9574
UL27681	LAQDY6083	UL27681	LQDY9579
UL27681	LAQDY6087	UL27681	LQDY9672
UL27681	LDRCZ10247	UL27681	LQDY9770
UL27681	LDRCZ10277	UL27681	LQDY9783
UL27681	LDRCZ10318	UL27681	LQDY9786
UL27681	LDRCZ10335	UL27681	LQDY9900
UL27681	LDRCZ10430	UL27681	LQDY9902
UL27681	LDRCZ10531	UL27681	LQDY9929
UL27681	LDRCZ10750	UL27681	LQDY9957
UL27681	LDRCZ10899	UL27681	LQDY9982
UL27681	LDRCZ11616	UL27681	LQDY9992
UL27681	LDRCZ11720	UL27681	WGQDY90005
UL27681	LDRCZ11893

(2) Use the compliance schedule in Table 2 of this AD.

Table 2.—Compliance Schedule for HP Turbine Discs Listed in Table 1

If Disc Cycles-Since-New (CSN) on October 8, 2004 are:	Then Eddy Current Inspect:
(1) 12,750 CSN or more	Within 250 cycles-in-service (CIS) from October 8, 2004 or within 14,500 CSN, whichever occurs first.
(2) Fewer than 12,750 CSN but 10,500 CSN or more	Within 500 CIS from October 8, 2004.
(3) Fewer than 10,500 CSN	Before 11,000 CSN or at next shop visit after the effective date of this AD, whichever occurs first.

(3) On discs that pass inspection, use paragraph 3. of the Accomplishment Instructions of RR ASB No. RB.211-72-AE651, dated November 22, 2004, to permanently etch NMSB 72-AE651 onto the disc, adjacent to the part number.

(4) Perform an eddy current inspection of the HP turbine discs listed in Table 3 of this AD, for cracks in the rim cooling air holes. Use paragraph 3. of the Accomplishment Instructions of RR ASB No. RB.211-72-AE651, dated November 22, 2004, to perform the eddy current inspection.

Table 3.—Affected HP Turbine Discs Using Compliance Schedule in Table 4

Part No.	Serial No.
UL10323	CQDY6070 and higher.
UL27680	All.
UL27681	All.
LK80622	LQDY6316 and higher.
LK80623	CQDY5945 and higher.
UL28267	All.

(5) Use the compliance schedule in Table 4 of this AD.

Table 4.—Compliance Schedule for HP Turbine Discs Listed in Table 3

If Disc CSN on January 29, 2001 are:	Then Eddy Current Inspect:
(1) Fewer than 13,700 CSN	Before reaching 14,500 CSN, or at the next shop visit after the effective date of this AD, whichever occurs first.
(2) 13,700 CSN or more	Before reaching one of the following, whichever occurs first after the effective date of this AD: (i) 15,300 CSN. (ii) Within 800 CIS since January 29, 2001. (iii) At next shop visit.

(6) For discs that pass inspection, use paragraph 3. of the Accomplishment Instructions of RR ASB No. RB.211-72-AE651, dated November 22, 2004, to permanently etch NMSB 72-AE651 onto the disc, adjacent to the part number.

Eddy Current Inspection for Model RB211-22B-02 Engines

(g) For model RB211-22B-02 engines, do the following:

(1) Perform an eddy current inspection of the HP turbine discs listed in Table 5 of this AD, for cracks in the rim cooling air holes. Use paragraph 3. of the Accomplishment Instructions of RR ASB No. RB.211-72-AE717, dated January 21, 2005, to perform the eddy current inspection.

Table 5.—Affected HP Turbine Discs in RR Model RB211-02 Turbofan Engines

Part No.	Serial No.
LK80622	LQDY6316 and higher.
LK80623	CQDY5945 and higher.
UL28267	All.

(2) Use the compliance schedule in Table 6 of this AD.

Table 6.—Compliance Schedule for HP Turbine Discs Listed in Table 5

If Disc CSN on January 1, 2005 are:	Then Eddy Current Inspect:
(1) More than 9,000 CSN	Within 500 CIS after January 1, 2005, but before 11,000 CSN, whichever is sooner.
(2) More than 1,500, but fewer than 9,001 CSN	Before exceeding 9,500 CSN, or at the next shop visit after the effective date of this AD, whichever occurs first.

(3) For discs that pass inspection, use paragraph 3. of the Accomplishment Instructions of RR ASB No. RB.211-72-AE717, dated January 21, 2005, to permanently etch NMSB 72-AE717 onto the disc, adjacent to the part number.

Other Conditions for All Engines

(h) Do not perform the actions of this AD to a disc until that disc has reached at least 1,500 CSN.

(i) Engines with an affected HP turbine disc at shop visit on the effective date of this AD and without the HP turbine rotor installed in the combustor outer case, must have the disc eddy current inspected before assembling the engine.

(j) Engines with an affected HP turbine disc at shop visit on the effective date of this AD with the HPT rotor installed in the combustor case need not have the disc eddy current inspected at this time.

(k) HP turbine discs previously eddy current inspected at fewer than 1,500 CSN must be inspected again using this AD.

(l) Replace cracked HP turbine discs with a serviceable disc.

Definition

(m) For the purpose of this AD, next shop visit is defined as the first shop visit opportunity when the HPT rotor is removed from the combustion case.

(n) For the purpose of this AD, a serviceable part is one with cyclic life remaining and either not listed in any of the preceding tables or one listed in a preceding table, but previously eddy current inspected and permanently etch marked with the Service Bulletin (SB) number NMSB 72-AE651 or NMSB 72-C877 on the disc.

Previous Credit

(o) Previous credit is allowed for the actions in this AD for HP turbine discs with 1,500 CSN or more that were eddy current inspected using applicable RR SB No. RB.211-72-C817, Revision 2, dated March 7, 2001, RR TSD 594-J, Overhaul Processes Manual, Task 70-00-00-200-223, or RR SB No. RB.211-72-C877, Revision 1, dated March 7, 2001.

Reporting Requirements

(p) For all except model RB211-22B-02 engines, report findings of the inspection using paragraph 3.E. of the Accomplishment Instructions of RR ASB RB.211-72-AE651, dated November 22, 2004. The Office of Management and Budget (OMB) has approved the reporting requirements specified in paragraph 3.E. of the Accomplishment Instructions of RR ASB RB.211-72-AE651, dated November 22, 2004, and assigned OMB control number 2120-0056.

(q) For model RB211-22B-02 engines, report findings of the inspection using paragraph 3.E. of the Accomplishment Instructions of RR ASB RB.211-72-AE717, dated January 21, 2005. The OMB has approved the reporting requirements specified in paragraph 3.E. of the Accomplishment Instructions of RR ASB RB.211-72-AE717, dated January 21, 2005, and assigned OMB control number 2120-0056.

Alternative Methods of Compliance

(r) 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

(s) CAA Airworthiness Directive G-2004-0027, dated November 19, 2004, and CAA Airworthiness Directive G-2005-0003, dated January 24, 2005, also address the subject of this AD.

Issued in Burlington, Massachusetts, on January 19, 2006.

Peter A. White,

Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service.