03-19310. Airworthiness Directives; Rolls-Royce plc

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) RB211-22B series, RB211-524B, -524C2, -524D4, -524G2, -524G3, and -524H series, and RB211-535C and -535E series turbofan engines with high pressure compressor (HPC) stage 3 disc assemblies, part numbers (P/Ns) LK46210, LK58278, LK67634, LK76036, UL11706, UL15358, UL22577, UL22578, and UL24738 installed. This proposed AD would allow disc assemblies not modified by a certain RR service bulletin to reach their full life only after the disc assemblies are modified with anti-corrosion protection. This proposed AD is prompted by the manufacturer's reassessment of the corrosion risk on HPC stage 3 disc assemblies that have not yet been modified with sufficient application of anti-corrosion protection. The actions specified in this proposed AD are intended to prevent corrosion-induced uncontained disc failure, resulting in damage to the airplane.

DATES:

We must receive any comments on this proposed AD by September 29, 2003.

ADDRESSES:

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

• By mail: Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 2003-NE-12-AD, 12 New England Executive Park, Burlington, MA 01803-5299.
• By fax: [phone].
• By e-mail: [e-mail]

You may get the service information identified in this proposed AD from Rolls-Royce plc, PO Box 31, Derby, England, DE248BJ; telephone: [phone]; fax: [phone].

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:

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 submit any written relevant data, views, or arguments regarding this proposal. Send your comments to an address listed under ADDRESSES. Include “AD Docket No. 2003-NE-12-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 through a nonwritten communication, 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.

We are reviewing the writing style we currently use in regulatory documents. We are interested in your comments on whether the style of this document is clear, and your suggestions to improve the clarity of our communications that affect you. You may get more information about plain language at http://www.plainlanguage.gov.

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

The Civil Aviation Authority (CAA), which is the airworthiness authority for the U.K., recently notified the FAA that an unsafe condition may exist on RR RB211-22B series, RB211-524B, -524C2, -524D4, -524G2, -524G3, and -524H series, and RB211-535C and -535E series turbofan engines with HPC stage 3 disc assemblies, P/Ns LK46210, LK58278, LK67634, LK76036, UL11706, UL15358, UL22577, UL22578, and UL24738 installed. The CAA advises that numerous disc assemblies have been found at overhaul inspection having corrosion-induced pitting. RR has reassessed the risk of corrosion-induced pitting of disc assemblies that have not incorporated any revision of RR service bulletin (SB) No. RB.211-72-9434, or any revision of RR SB No. RB.211-72-5420, which rework the discs and apply anti-corrosion protection, and RR has lowered the disc lives accordingly in the Time Limits Manuals.

Relevant Service Information

We have reviewed and approved the technical contents of Rolls-Royce plc SB No. RB.211-72-9434, Revision 4, dated January 12, 2000, and SB No. RB.211-72-5420, dated February 29, 1980, which describe procedures for reworking of HP compressor stage 3 rotor disc assemblies by machining, and application of anti-corrosion protection. The CAA, which is the airworthiness authority for the U.K., classified these SBs as mandatory and issued airworthiness directive 004-01-94, dated January 4, 2002.

FAA's Determination and Requirements of the Proposed AD

These Rolls-Royce plc RR RB211-22B series, RB211-524B, -524C2, -524D4, -524G2, -524G3, and -524H series, and RB211-535C and -535E series turbofan engines are 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. Pursuant to this bilateral airworthiness agreement, the CAA has 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. Therefore, we are proposing this AD, which would require the following for affected HP compressor disc assemblies:

• Removing affected disc assemblies from service.
• Re-machining, inspecting, and applying anti-corrosion protection.
• Re-marking, and returning disc assemblies into service.

The proposed AD would require that these actions be done per the service information described previously.

Changes to 14 CFR Part 39—Effect on the Proposed AD

On July 10, 2002, we published a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs the FAA's AD system. This regulation now includes material that relates to altered products, special flight permits, and alternative methods of compliance. This material previously was included in each individual AD. Since this material is included in 14 CFR part 39, we will not include it in future AD actions.

Costs of Compliance

There are approximately 2,000 RR RB211-22B series, RB211-524B, -524C2, -524D4, -524G2, -524G3, and -524H series, and RB211-535C and -535E series turbofan engines of the affected design in the worldwide fleet. We estimate that 1,000 engines installed on airplanes of U.S. registry would be affected by this proposed AD. We also estimate that it would take approximately 31 work hours per engine to perform the proposed actions, and that the average labor rate is $65 per work hour. Required parts would cost approximately $38,000 per engine. Based on these figures, the total cost of the proposed AD to U.S. operators is estimated to be $40,015,000.

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. 2003-NE-12-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 adding the following new airworthiness directive:

Rolls-Royce plc: Docket No. 2003-NE-12-AD.

Comments Due Date

(a) The FAA must receive comments on this airworthiness directive (AD) action by September 29, 2003.

Affected ADs

(b) None.

Applicability

(c) This AD is applicable to Rolls-Royce plc (RR) RB211-22B series, RB211-524B, -524C2, -524D4, -524G2, -524G3, and -524H series, and RB211-535C and -535E series turbofan engines with high pressure compressor (HPC) stage 3 disc assemblies, part numbers (P/Ns) LK46210, LK58278, LK67634, LK76036, UL11706, UL15358, UL22577, UL22578, and UL24738 installed. These engines are installed on, but not limited to, Boeing 747, Boeing 757, Boeing 767, Lockheed L-1011, and Tupolev Tu204 series airplanes.

Unsafe Condition

(d) This AD was prompted by the manufacturer's reassessment of the corrosion risk on HPC stage 3 disc assemblies that have not been modified sufficiently with application of anti-corrosion protection. The actions specified in this AD are intended to prevent corrosion-induced uncontained disc failure, resulting in 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.

Removal of HPC Stage 3 Discs

(f) Remove from service affected HPC stage 3 disc assemblies identified in the following Table 1, using one of the following criteria:

Table 1.—Affected HPC Stage 3 Disc Assemblies

Engine model	Rework band for cycle life accumulated on disc assemblies P/Ns LK46210 and LK58278 (pre RR service bulletin (SB) No. RB.211-72-5420)	Rework band for cycle life accumulated on disc assembly P/N LK67634 (pre RR SB No. RB.211-72-5420)	Rework band for cycle life accumulated on P/Ns LK76036, UL11706, UL15358, UL22577, UL22578, and UL24738 disc assemblies (pre RR SB No. RB.211-72-9434)
-22B series	4,000-6,200	7,000-10,000	11,500-14,000
-535E4 series	N/A	N/A	9,000-15,000
-524B-02, B-B-02, B3-02, and B4 series, Pre and SB No. 72-7730	4,000-6,000	7,000-9,000	11,500-14,000
-524B2 and C2 series, Pre SB No. 72-7730	4,000-6,000	7,000-9,000	11,500-14,000
-524B2-B-19 and C2-B-19, SB No. 72-7730	4,000-6,000	7,000-9,000	8,500-11,000
-524D4 series, Pre SB No. 72-7730	4,000-6,000	7,000-9,000	11,500-14,000
-524D4-B series, SB No. 72-7730	4,000-6,000	7,000-9,000	8,500-11,000
-524G2, G3, H, and H2 series	4,000-6,000	7,000-9,000	8,500-11,000

(1) For discs that entered into service before 1992, remove disc and rework as specified in paragraph (g)(2) of this AD, within five years from the effective date of this AD, but not to exceed the upper cyclic limit of Table 1 of this AD before rework. Discs reworked may not exceed the published cyclic limit in the manufacturer's Time Limits Manual.

(2) For discs that entered into service in 1992 or later, remove disc within the cyclic life rework bands in Table 1 of this AD, or within 17 years after the date of the disc assembly entering into service, whichever is sooner, but not to exceed the upper cyclic limit of Table 1 of this AD before rework. Discs reworked may not exceed the published cyclic life in the manufacturer's Time Limits Manual.

(3) For disc assemblies that when new, were modified with an application of anti-corrosion protection and re-marked to P/N LK76036 (not previously machined) as specified by Part 1 of the original issue of RR service bulletin (SB) No. RB.211-72-5420, dated April 20, 1979, remove RB211-22B disc assemblies before accumulating 10,000 cycles-in-service (CIS), and remove RB211-524 disc assemblies before accumulating 9,000 CIS.

(4) If the disc assembly date of entry into service cannot be determined, the date of disc manufacture may be obtained from RR and used instead.

Optional Rework of HPC Stage 3 Discs

(g) Rework HPC stage 3 disc assemblies that were removed in paragraph (f) of this AD as follows:

(1) For disc assemblies that when new, were modified with an application of anti-corrosion protection and re-marked to P/N LK76036 (not previously machined) as specified by Part 1 of the original issue of RR SB RB.211-72-5420, dated April 20, 1979, rework disc assemblies and re-mark to either LK76034 or LK78814 in accordance with paragraph 2.B. of the Accomplishment Instructions of RR SB No. RB.211-72-5420, Revision 4, dated February 29, 1980. This rework constitutes terminating action to the removal requirements in paragraph (f) of this AD.

(2) For all other disc assemblies, rework in accordance with Paragraph 3B. of the Accomplishment Instructions of RR SB No. RB.211-72-9434, Revision 4, dated January 12, 2000. This rework constitutes terminating action to the removal requirements in paragraph (f) of this AD.

Note 1:

If rework is done on disc assemblies that are removed before the disc assembly reaches the lower life of the cyclic life rework band in Table 1 of this AD, artificial aging of the disc to the lower life of the rework band, at time of rework, is required.

Alternative Methods of Compliance

(h) Alternative methods of compliance must be requested in accordance with 14 CFR part 39.19, and must be approved by the Manager, Engine Certification Office, FAA.

Material Incorporated by Reference

(i) The rework must be done in accordance with the following Rolls Royce service bulletins:

Document No.	Pages	Revision	Date
RB.211-72-5420	1	4	February 29, 1980.
	2	3	January 12, 1980.
	3-8	4	February 29, 1980.
	9-10	Original	April 20, 1979.
Total pages: 8
RB.211-72-9434	All	4	January 12, 2000.
Total pages: 20

Approval of incorporation by reference from the Office of the Federal Register is pending.

Related Information

(j) The subject of this AD is addressed in Civil Aviation Authority airworthiness directive 004-01-94.

Issued in Burlington, Massachusetts, on July 24, 2003.

Francis A. Favara,

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