E6-10771. Airworthiness Directives; Rolls-Royce plc RB211-524 Series Turbofan Engines

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) RB211-524 series turbofan engines with certain part number (P/N) intermediate pressure compressor (IPC) stage 5 disks installed. That AD currently requires new reduced IPC stage 5 disk cyclic limits. This proposed AD would require the same reduced IPC stage 5 disk cyclic limits, the requirement to remove from service affected disks that already exceed the new reduced cyclic limit, and to remove from service other affected disks before exceeding their cyclic limits using a drawdown schedule. This proposed AD also would exempt disks reworked to RR Service Bulletin (SB) RB.211-72-E182, Revision 1, dated July 30, 2004, and would allow an on-wing eddy current inspection (ECI) on RB211-524G and RB211-524H series engines. This proposed AD results from the manufacturer issuing a revised Alert Service Bulletin (ASB) to remove certain disks from applicability, and to allow an on-wing ECI on RB211-524G and RB211-524H series engines. We are proposing this AD to prevent failure of the IPC stage 5 disk, which could result in uncontained engine failure and possible damage to the airplane.

DATES:

We must receive any comments on this proposed AD by September 11, 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. 2002-NE-40-AD, 12 New England Executive Park, Burlington, MA 01803.
• By fax: [phone].
• By e-mail: [e-mail].

You can get the service information identified in this proposed AD from Rolls-Royce plc, P.O. Box 31 Derby, DE248BJ, United Kingdom; 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; 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. 2002-NE-40-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 July 18, 2005, the FAA issued AD 2005-15-13, Amendment 39-14202 (70 FR 43036, July 26, 2005). That AD requires:

• Establishing new reduced IPC stage 5 disk cyclic limits.
• Removing from service affected disks that already exceed the new reduced cyclic limit.
• Removing from service other affected disks before exceeding their cyclic limits, using a drawdown schedule.
• Allowing optional inspections at each shop visit or an on-wing ECI to extend the disk life beyond the specified life.

Actions Since We Issued AD 2005-15-13

Since we issued that AD, the manufacturer issued a new revision to ASB RB.211-72-AD428 to reference AD G-2005-0008.

Relevant Service Information

We have reviewed and approved the technical contents of RR ASB No. RB.211-72-AD428, Revision 5, dated March 18, 2005, that specifies a drawdown schedule for removing from service affected IPC stage 5 disks, using new RR Time Limits Manual (TLM), 05-10-01 cyclic limits. The ASB also describes procedures for optional inspections at each shop visit to extend the disk life beyond the lives specified. The Civil Aviation Authority (CAA), the airworthiness authority of the United Kingdom (U.K.), has classified this service bulletin as mandatory and issued AD G-2005-0008 to ensure the airworthiness of these RR turbofan engines in the U.K. We have also reviewed and approved the technical contents of the following SBs:

• SB No. RB.211-72-E148, dated March 13, 2003,
• SB No. RB.211-72E150, Revision 1, dated June 4, 2003, and
• SB No. RB.211-72-E171, Revision 1, dated February 8, 2005.

These SBs provide an optional on-wing ECI of the affected disks, to extend the disk life beyond the lives specified.

Differences Between the Proposed AD and the Service Information

This proposed AD adds a requirement to comply with the reduced cyclic life limits not later than 30 days after the effective date of this AD.

Bilateral Agreement Information

This engine model is manufactured in the U.K., 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 us informed of the situation described above.

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:

• Establishing new reduced IPC stage 5 disk cyclic limits.
• Removing from service affected disks that already exceed the new reduced cyclic limit.
• Removing from service other affected disks before exceeding their cyclic limits, using a drawdown schedule.
• Allowing optional inspections at each shop visit or an on-wing ECI to extend the disk life beyond the specified life.

The proposed AD would require you to use the service information described previously to perform these actions.

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

On July 10, 2002, we issued a new version of 14 CFR part 39 (67 FR 47998, 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

We estimate this proposed AD would not affect any engines installed on airplanes of U.S. registry. Based on this, we estimate this proposed AD will not have any cost to U.S. operators.

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. 2002-NE-40-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 39-14202 (70 FR 43036, July 26, 2005) and by adding a new airworthiness directive, to read as follows:

Rolls-Royce plc: Docket No. 2002-NE-40-AD.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by September 11, 2006.

Affected ADs

(b) This AD supersedes AD 2005-15-13, Amendment 39-14202.

Applicability

(c) This AD applies to the Rolls-Royce plc (RR) RB211-524 series turbofan engines listed in the following Table 1, with intermediate pressure compressor (IPC) stage 5 disk part numbers (P/Ns) listed in Table 2 of this AD, installed.

Table 1.—Engine Models Affected

-524B-02	-524B-B-02	-524B3-02	-524B4-02	-524B4-D-02
-524B2-19	-524B2-B-19	-524C2-19	-524C2-B-19	-524D4-19
-524D4-B-19	-524D4X-19	-524D4X-B-19	-524D4-39	-524D4-B-39
-524G2-19	-524G2-T-19	-524G3-19	-524G3-T-19	-524H2-19
-524H2-T-19	-524H-36	-524H-T-36

These engines are installed on, but not limited to, Boeing 747, 767, and Lockheed L-1011 airplanes.

Table 2.—IPC Stage 5 Disk P/Ns Affected

LK60130	LK65932	LK69021	LK81269	LK83282
LK83283	UL12290	UL15743	UL15744	UL15745
UL19132	UL20785	UL20832	UL23291	UL25011
UL36821	UL36977	UL36978	UL36979	UL36980
UL36981	UL36982	UL36983	UL37078	UL37079
UL37080	UL37081	UL37082	UL37083	UL37084

Unsafe Condition

(d) This AD results from the manufacturer issuing a revised Alert Service Bulletin (ASB) to remove certain disks from applicability and to allow an on-wing eddy current inspection (ECI) on RB211-524G and RB211-524H series engines. The actions specified in this AD are intended to prevent failure of the IPC stage 5 disk, which could result in uncontained engine failure and possible 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.

Exempted Disks

(f) For engines with an IPC stage 5 disk P/N listed in Table 2 of this AD, reworked to RR SB No. RB.211-72-E182, Revision 1, dated July 30, 2004, no further action is necessary.

Cycle Limits

(g) Comply with the reduced cyclic life limits in Table 3 of this AD or conduct qualifying nondestructive test (NDT) inspections to extend the IPC stage 5 disk life within 30 days after the effective date of this AD, but before December 1, 2008.

Table 3.—Cyclic Life Limits Without Qualifying NDT Inspection

Engine models
Date of reduced life limit	-524G2, G2-T, G3, G3-T, H2, H2-T, H-36, H-T-36	-524D4, D4-B, D4-B-39, D4X, D4X-B, D4-39	-524B2, B2-B, C2, C2-B	-524B-02, B-B-02, B3-02, B4-02, B4-D-02
November 30, 2002	13,500 cycles-in-service (CIS)	16,150 CIS	16,000 CIS	16,200 CIS
April 1, 2003	13,500 CIS	13,500 CIS	13,500 CIS	14,000 CIS
December 1, 2003	12,000 CIS	13,500 CIS	13,500 CIS	14,000 CIS
December 1, 2004	11,000 CIS	13,500 CIS	12,000 CIS	12,000 CIS
December 1, 2005	11,000 CIS	12,000 CIS	12,000 CIS	12,000 CIS

(h) On December 1, 2008, the revised cyclic life limits specified in Table 4 of this AD become effective. Incorporate the revised cyclic life limits specified in Table 4 of this AD into the RR Time Limits Manual, 05-10-01.

Table 4.—Cyclic Life Limits on December 1, 2008

Engine models
Date of reduced life limit	-524G2, G2-T, G3, G3-T, H2, H2-T, H-36, H-T-36	-524D4, D4-B, D4-B-39, D4X, D4X-B, D4-39	-524B2, B2-B, C2, C2-B	-524B-02, B-B-02, B3-02, B4-02, B4-D-02
December 1, 2008	7,830 CIS	8,700 CIS	8,900 CIS	9,000 CIS

Optional Inspections

(i) Before December 1, 2008, you may perform an optional NDT inspection on-wing or at each shop visit to extend the disk life. Guidance for these inspections is provided in paragraphs (j) or (k) of this AD.

Optional Inspections at Shop Visit

(j) Perform optional inspections at shop visit, as follows:

(1) Remove corrosion protection from IPC stage 5 disk. Information on corrosion protection removal can be found in the Engine Maintenance Manual.

(2) Perform a visual inspection and a binocular inspection of the IPC stage 5 disk for corrosion pitting at the cooling air holes and defender holes in the disk front spacer arm. Follow paragraph 3.C. of the Accomplishment Instructions of RR ASB No. RB.211-72-AD428, Revision 5, dated March 18, 2005. The RR Engine Maintenance Manual, Inspection Check-00 (ATA 72-32-31-200-000), contains limits for corrosion pitting of the IPC stage 5 disk.

(3) If the disk has corrosion pitting in excess of limits, remove the disk from service.

(4) If the disk is free from corrosion pitting, perform a magnetic penetrant inspection (MPI) of the entire disk as follows:

(i) For RB211-524G2-T, RB211-524G3-T, and RB211-524H-T series engines, the RR Engine Maintenance Manual, Inspection Check 08 (ATA 72-32-31-200-008), contains limits for corrosion pitting of the IPC stage 5 disk.

(ii) For RB211-524G2, RB211-524G3, and RB211-524H series engines, the RR Engine Maintenance Manual, Inspection Check 09 (ATA 72-32-31-200-009), contains limits for corrosion pitting of the IPC stage 5 disk.

(iii) If the disk passes the MPI and you find no cracks, complete all other inspections, re-apply corrosion protection to the disk, and return the disk to service using the cyclic limits allowed by paragraph (m) of this AD. RR Repair FRS5900 contains information on re-applying corrosion protection.

(5) If the disk has corrosion pitting that is within limits, do the following:

(i) Perform an ECI on all disk cooling air holes, defender holes, and inner and outer faces. Use paragraph 3.D. of the Accomplishment Instructions of RR ASB No. RB.211-72-AD428, Revision 5, dated March 18, 2005. The RR Engine Maintenance Manual, Inspection Check-00 (ATA 72-32-31-200-000), contains limits for corrosion pitting of the IPC stage 5 disk.

(ii) If the disk passes the ECI and you find no cracks, perform an MPI on the entire disk.

(iii) If the disk passes the MPI and you find no cracks, re-apply corrosion protection to the disk, and return the disk to service using the cyclic limits allowed by paragraph (m) of this AD.

Optional On-Wing Eddy Current Inspections

(k) You may perform an optional on-wing ECI of the IPC stage 5 disk only once between shop visit inspections as follows:

(1) For RB211-524B2/C2 and RB211-524B4/D4 series engines, use paragraphs 3.A. through 3.F. of the Accomplishment Instructions of RR SB No. RB.211-72-E148, dated March 13, 2003, and RR SB No. RB.211-72-E150, Revision 1, dated June 4, 2003.

(2) For RB211-524G2, RB211-524G2-T, RB211-524G3, RB211-524G3-T, RB211-524H, and RB211-524H-T series engines, use paragraphs 3.A. through 3.M. of the Accomplishment Instructions of RR SB No. RB.211-72-E171, Revision 1, dated February 8, 2005.

(3) If the disk passes the ECI and you find no cracks, you may extend the cycle life as specified in paragraph (m) of this AD.

Definition of Shop Visit

(l) The manufacturer defines a shop visit as the separation of an engine major case flange. This definition excludes shop visits when only field maintenance type activities are performed in lieu of performing them on-wing (such as to perform an on-wing inspection of a tail engine installation on a Lockheed L-1011 airplane).

Cyclic Life Extension

(m) Disks that pass an optional inspection may remain in service after that inspection for the additional cycles listed in the following Table 5, until the next inspection, until the cyclic life limit published in the RR Time Limits Manual, 05-10-01, is reached, or December 1, 2008, whichever occurs first.

Table 5.—Cyclic Life Extension

Engine models
Type of extension	-524G2, G2-T, G3, G3-T, H2, H2-T, H-36, H-T-36	-524D4, D4-B, D4-B-39, D4X, D4X-B, D4-39	-524B2, B2-B, C2, C2-B	-524B-02, B-B-02, B3-02, B4-02, B4-D-02
Extension After Passing MPI	1,600 cycles	2,000 cycles	2,000 cycles	2,000 cycles
Extension After Passing In-Shop ECI	3,800 cycles	4,500 cycles	4,500 cycles	4,500 cycles
Extension After Passing On-Wing ECI	1,000 cycles	1,200 cycles	1,200 cycles	1,200 cycles

Disks That Have Been Intermixed Between Engine Models

(n) The RR Time Limits Manual, 05-00-01, contains information on intermixing disks between engine models.

Alternative Methods of Compliance

(o) 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.

Credit for Previous Inspections

(p) Inspections done using RR SB No. RB.211-72-E150, dated April 17, 2003, SB No. RB.211-72-E171, dated December 14, 2004, SB No. RB.211-72-D428, Revision 3, dated June 30, 2003, and ASB No. RB.211-72-AD428, Revision 4, dated March 7, 2005, meet the requirements of this AD.

Reporting Requirement

(q) Report findings of all inspections of the IPC stage 5 disk using paragraph 3.B.(2) of the Accomplishment Instructions of RR No. ASB RB.211-72-AD428, Revision 5, dated March 18, 2005. The Office of Management and Budget (OMB) has approved the reporting requirements specified in Paragraph 3.B. of the Accomplishment Instructions of RR No. ASB RB.211-72-AD428, Revision 5, dated March 18, 2005, and assigned OMB control number 2120-0056.

Related Information

(r) CAA airworthiness directive G-2005-0008, dated March 8, 2005, also addresses the subject of this AD.

Issued in Burlington, Massachusetts, on June 30, 2006.

Thomas A. Boudreau,

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