02-4367. Airworthiness Directives; Rolls-Royce plc (RR) RB211-535E4 Series Turbofan Engines

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The Federal Aviation Administration (FAA) proposes to adopt a new airworthiness directive (AD) that is applicable to RR RB211-535E4 series turbofan engines. This proposal would require disassembling and inspecting all engine mounts for cracks, refurbishing the engine mounts, and replacing the front mount thrust link spherical bearing. This proposal is prompted by reports of corrosion and fatigue cracks in the mount pins, the spherical bearings, and the support links and their respective spherical bearings. The actions specified by the proposed AD are intended to prevent failure of the engine mounts due to cracks that could result in loss of an engine.

DATES:

Comments must be received by April 29, 2002.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 2001-NE-13-AD, 12 New England Executive Park, Burlington, MA 01803-5299. Comments may be inspected at this location, by appointment, between 8 a.m. and 4:30 p.m., Monday through Friday, except Federal holidays. Comments may also be sent via the Internet using the following address: [e-mail]. Comments sent via the Internet must contain the docket number in the subject line.

FOR FURTHER INFORMATION CONTACT:

Keith Mead, 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

Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications should identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this action may be changed in light of the comments received.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2001-NE-13-AD.” The postcard will be date stamped and returned to the commenter.

Availability of NPRM's

Any person may obtain a copy of this NPRM by submitting a request to the FAA, New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 2001-NE-13-AD, 12 New England Executive Park, Burlington, MA 01803-5299.

Discussion

The Civil Aviation Authority (CAA), which is the airworthiness authority for the United Kingdom (UK), recently notified the FAA that an unsafe condition may exist on RR RB211-535E4 series turbofan engines. The CAA advises that there have been reports of stress and fatigue cracks found in engine mount assemblies, part numbers (P/N's) B71210101 (front) and B71210201 (rear). There were two instances of rear mount pin cracking, two instances of front mount spherical bearing cracking, corrosion of the rear mount support links and their respective spherical bearings, and a number of instances of cracking in the center spherical bearing of the front mount thrust link. Because this condition could cause failure of the engine mounts due to cracks that could result in loss of an engine, the CAA considers it necessary to make disassembly and inspection of these engine mounts mandatory. The CAA has issued AD 004-08-2000, dated March 31, 2001, in order to assure the airworthiness of these Rolls-Royce engines in the UK.

Bilateral Agreement Information

This engine model is manufactured in the UK, and is type certificated for operation in the United States under the provisions of § 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 the FAA informed of the situation described above. The FAA has 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.

Proposed Requirements of this AD

Since an unsafe condition has been identified that is likely to exist or develop on other RR RB211-535E4 series turbofan engines of the same type design that are used on airplanes registered in the United States, the proposed AD would require complete disassembling of the engine mounts, P/N's B71201101 and B71210201, inspecting for cracks, refurbishing the engine mounts, and replacing the front mount thrust link spherical bearing. These actions would be required to be done before accumulating 12,000 cycles-since-new (CSN) or 36,000 engine-hours-since-new (EHSN), whichever is earlier, if engine cycles at next shop visit exceeds 5,000 cycles, and thereafter within every 12,000 cycles-since-last-compliance or 36,000 hours-since-last-compliance, whichever is earlier. For engines with greater than 12,000 CSN or 36,000 EHSN, these actions would be required to be done within 500 cycles-in-service, or 1,500 engine-hours-in-service, whichever is earlier.

Economic Analysis

There are approximately 1,128 engines of the affected design in the worldwide fleet. The FAA estimates that 500 engines installed on airplanes of U.S. registry would be affected by this proposed AD. The FAA also estimates that it would take approximately 32 work hours per engine to accomplish the proposed actions, and that the average labor rate is $60 per work hour. Required parts would cost approximately $491 per engine. Based on these figures, the total cost impact of the proposed AD on U.S. operators is estimated to be $1,205,500.

Regulatory Analysis

This proposed rule does not have federalism implications, as defined in Executive Order 13132, because it 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. Accordingly, the FAA has not consulted with state authorities prior to publication of this proposed rule.

For the reasons discussed above, I certify that this 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) if promulgated, will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend part 39 of the Federal Aviation Regulations (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. Section 39.13 is amended by adding the following new airworthiness directive:

Rolls-Royce plc: Docket No. 2001-NE-13-AD.

Applicability: This airworthiness directive (AD) is applicable to Rolls-Royce plc (RR) Model RB211-535E4-37, -535E4-B-37 and -535E4-B-75 turbofan engines with engine mount assemblies, part numbers (P/N's) B71210101 and B71210201, installed. These engines are installed on, but not limited to Boeing 757 series and Tupolev Tu204-120 airplanes.

Note 1:

This AD applies to each engine identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For engines that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (c) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance

Compliance with this AD is required as indicated, unless already done.

To prevent failure of the engine mounts due to cracks that could result in loss of an engine, do the following:

Inspection of Engine Mounts for Cracks

(a) Using the compliance times specified in the following Table, do the following actions:

Number of Cycles-Since-New (CSN) or Engine-Hours-Since-New (EHSN) on the effective date of this AD	Initial compliance	Repetitive compliance by the earlier of—
(1) Fewer than 5,000 CSN	At the next shop visit after accumulating 5,000 CSN, but not to exceed 12,000 CSN or 36,000 EHSN	(i) 12,000 cycles-since-last-compliance (CSLC), or (ii) 36,000 engine-hours-since-last-compliance (EHSLC).
(2) 5,000 to 12,000 CSN or 12,000 to 36,000 EHSN	At the next shop visit, but not to exceed 12,000 CSN or 36,000 EHSN	(i) 12,000 CSLC, or (ii) 36,000 EHSLC.
(3) Greater than 12,000 CSN or 36,000 EHSN	Within 500 cycles-in-service or 1,500 engine hours-in-service, whichever is earlier, after the effective date of the AD	(i) 12,000 CSLC, or (ii) 36,000 EHSLC.

(4) Disassemble front engine mounts, P/N 71210101, and rear engine mounts, P/N 71210201. Procedures for disassembly and inspection/check of the engine mounts can be found in sections 71-21-01 and 71-21-02 of the engine manual (EM).

(5) Inspect for cracks using the Fluorescent Penetrant or Magnetic Particle inspection methods.

(6) Assemble the engine mounts, insuring application of OMat 4/23 Neverseez. Procedures for assembling the engine mounts can be found in sections 71-21-01 and 71-21-02 of the EM.

Credit for Previous Compliance

(b) Compliance with RR Service Bulletin (SB) RB.211-71-5291 constitutes compliance with the initial compliance requirements or repetitive compliance requirements specified in paragraph (a) of this AD.

Alternative Methods of Compliance

(c) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Engine Certification Office (ECO). Operators must submit their request through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, ECO.

Note 2:

Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the ECO.

Special Flight Permits

(d) Special flight permits may be issued in accordance §§ 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be done.

Note 3:

The subject of this AD is addressed in CAA airworthiness directive 004-08-2000, dated March 13, 2001, and in RR SB No. RB.211-71-5291, Revision 14, dated March 13, 2001.

Issued in Burlington, Massachusetts, on February 19, 2001.

Jay J. Pardee,

Manager, Engine and Propeller Directorate, Aircraft Certification Service.