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Proposed Rule

Airworthiness Directives; Rolls-Royce plc RB211 Series Turbofan Engines

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Information about this document as published in the Federal Register.

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Start Preamble

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to supersede an existing 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. That AD requires removing from service certain disc assemblies before they reach their full life if not modified with anticorrosion protection. This proposed AD would require the same actions as AD 2004-01-20, but would shorten the compliance time for disks that entered service before 1990. This proposed AD results from the manufacturer's reassessment of the corrosion risk on HPC stage 3 disc assemblies not modified with sufficient application of anticorrosion protection. We are issuing this AD to prevent corrosion-induced uncontained disc failure, resulting in damage to the airplane.

DATES:

We must receive comments on this proposed AD by September 26, 2005.

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. 2003-NE-12-AD, 12 New England Executive Park, Burlington, MA 01803-5299.
  • By fax: (781) 238-7055.
  • By e-mail: 9-ane-adcomment@faa.gov.

You can get the service information identified in this proposed AD from Rolls-Royce plc, PO Box 31, Derby, England, DE248BJ; telephone: 011-44-1332-242424; fax: 011-44-1332-245-418.

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.

Start Further Info

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.

End Further Info End Preamble Start Supplemental Information

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. 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 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 January 8, 2004, we issued AD 2004-01-20, Amendment 39-13434 (69 FR 2661, January 20, 2004). That AD allows certain disc assemblies to reach their full life only after modifying the disc assemblies with anticorrosion protection. The Civil Aviation Authority (CAA), which is the airworthiness authority for the United Kingdom, 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 inspections at overhaul found many disc assemblies with corrosion-induced pitting. RR 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 anticorrosion protection, lowered the disc lives from those published in the Time Limits Manuals. These SBs rework the discs and apply anticorrosion protection, and lower the disc lives accordingly in the Time Limits Manuals.

Actions Since AD 04-01-20 Was Issued

Since we issued that AD, we found that we made an oversight in the rule regarding the compliance time for disks that entered into service before 1990. We allowed operators to remove and rework these disks within five years after the effective date of that AD, but we intended to set a fixed calendar date based on inspection findings and metallurgical results. This proposed AD corrects that oversight. Also, we omitted paragraph (f)(5) from the original rule. We issued a correction to AD 04-01-20 on July 29, 2004, to include paragraph (f)(5). This proposed rule includes that paragraph.

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, Revision 4, dated February 29, 1980, which describe procedures for reworking of HPC stage 3 rotor disc assemblies by machining, and application of anticorrosion 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.

Bilateral Agreement Information

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. In keeping with 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 Start Printed Page 43660of this type design that are certificated for operation in the United States.

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. We are proposing this AD, which would require the following for affected HPC stage 3 rotor disc assemblies:

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

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

Costs of Compliance

There are about 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 this proposed AD would affect 1,000 engines installed on airplanes of U.S. registry. We also estimate that it would take about 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 about $38,000 per engine. Based on these figures, we estimate the total cost of the proposed AD to U.S. operators to be $40,015,000.

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. 2003-NE-12-AD” in your request.

Start List of Subjects

List of Subjects in 14 CFR Part 39

End List of Subjects

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:

Start Part

PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

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Authority: 49 U.S.C. 106(g), 40113, 44701.

End Authority
[Amended]

2. The FAA amends § 39.13 by removing Amendment 39-13434 (69 FR 2661, January 20, 2004) and by adding a new airworthiness directive, to read as follows:

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

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by September 26, 2005.

Affected ADs

(b) This AD supersedes AD 2004-01-20, Amendment 39-13434.

Applicability

(c) This AD applies to Rolls-Royce plc (RR) RB211-22B series, RB211-524B, -4C2, -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 results from the manufacturer's reassessment of the corrosion risk on HPC stage 3 disc assemblies that have not yet been modified with sufficient application of anticorrosion 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: Start Printed Page 43661

Table 1.—Affected HPC Stage 3 Disc Assemblies

Engine modelRework band for cyclic life accumulated on disc assemblies P/Ns LK46210 and LK58278 (Pre RR service bulletin (SB) No. RB.211-72-5420)Rework band for cyclic life accumulated on disc assembly P/N LK67634 (Pre RR SB No. RB.211-72-5420)Rework band for cyclic life accumulated on P/Ns LK76036, UL11706, UL15358, UL22577, UL22578, and UL24738 disc assemblies (Pre RR SB No. RB.211-72-9434)
-22B series4,000-6,2007,000-10,00011,500-14,000
-535E4 seriesN/AN/A9,000-15,000
-524B-02, B-B-02, B3-02, and B4 series, Pre and SB No. 72-77304,000-6,0007,000-9,00011,500-14,000
-524B2 and C2 series, Pre SB No. 72-77304,000-6,0007,000-9,00011,500-14,000
-524B2-B-19 and C2-B-19, SB No. 72-77304,000-6,0007,000-9,0008,500-11,000
-524D4 series, Pre SB No. 72-77304,000-6,0007,000-9,00011,500-14,000
-524D4-B series, SB No. 72-77304,000-6,0007,000-9,0008,500-11,000
-524G2, G3, H, and H2 series4,000-6,0007,000-9,0008,500-11,000

(1) For discs that entered into service before 1990, remove disc and rework as specified in paragraph (g)(2) of this AD, on or before January 4, 2007, but not to exceed the upper cyclic limit in Table 1 of this AD before rework. Discs reworked may not exceed the manufacturer's published cyclic limit in the time limits section of the manual.

(2) For discs that entered into service in 1990 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 manufacturer's published cyclic limit in the time limits section of the manual.

(3) For disc assemblies that when new, were modified with an application of anticorrosion 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.

(5) Discs in RB211-535C operation are unaffected by the interim rework cyclic band limits in Table 1 of this AD, but must meet the calendar life requirements of either paragraph (f)(1) or (f)(2) of this AD, as applicable.

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 anticorrosion 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 using 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 using Paragraph 3.B. 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) 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

(i) Civil Aviation Authority airworthiness directive 004-01-94, dated January 4, 2002, and RR Mandatory Service Bulletin No. RB.211-72-9661, Revision 4, dated January 4, 2002, pertain to the subject of this AD.

Start Signature

Issued in Burlington, Massachusetts, on July 21, 2005.

Francis A. Favara,

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

End Signature End Part End Supplemental Information

[FR Doc. 05-14803 Filed 7-27-05; 8:45 am]

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