02-3162. Airworthiness Directives; Rolls-Royce plc RB211-524G and -524H Series Turbofan Engines

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule; request for comments.

SUMMARY:

This amendment supersedes an existing airworthiness directive (AD) that is applicable to Rolls-Royce plc (RR) RB211-524G and -524H series turbofan engines. That AD currently requires initial and repetitive ultrasonic inspections for cracks in fan blade dovetail roots, and, if necessary, replacement with serviceable parts. That action also provides the options of installing improved design fan blades or reworking current fan blades to the improved configuration as terminating action for the inspections. This amendment requires initial inspection at lower thresholds, using either the blade root probe method or the surface wave probe method. This amendment also removes the option of reworking blades as terminating action for the inspections. Lastly, this amendment adds the model RB211-524H-T-36 engine to the applicability of this AD. This amendment is prompted by two additional reports of fan blade cracks found during inspections performed in accordance with the current AD. The actions specified in this AD are intended to detect cracked fan blades, which could result in an uncontained engine failure and damage to the airplane.

DATES:

Effective March 1, 2002. The incorporation by reference of certain publications listed in the rule is approved by the Director of the Federal Register as of March 1, 2002.

Comments for inclusion in the Rules Docket must be received on or before April 15, 2002.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 2000-NE-02-AD, 12 New England Executive Park, Burlington, MA 01803-5299. Comments may be inspected at this location, by appointment, between 8:00 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.

The service information referenced in this AD may be obtained from Rolls-Royce plc, PO Box 31, Derby, England; telephone: [phone]; fax: [phone]. This information may be examined at the FAA, New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

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:

The Civil Aviation Authority (CAA), which is the airworthiness authority for the United Kingdom (UK), had notified the Federal Aviation Administration (FAA) in March of 2000, that an unsafe condition may exist on certain Rolls-Royce plc (RR) RB211-524 series turbofan engines. The CAA had received reports of three fan blade failures up to that time. Subsequent inspections of the dovetail root area on other fan blades revealed the existence of dovetail root cracks in the same region as the failed blades.

The FAA issued AD 2000-05-12 to require initial and repetitive ultrasonic inspections for cracks in fan blade dovetail roots, and, if necessary, replacement with serviceable parts. That action also provided the options of installing improved design fan blades or reworking current fan blades to the improved configuration as terminating action for the inspections. Since that AD was published, two additional reports of fan blades found cracked have been received. The FAA has determined through information provided by RR that the fan blade inspection requirements and rejection criteria need to be changed. This condition, if not corrected, could result in possible multiple fan blade failures, which could result in an uncontained engine failure and damage to the aircraft.

Manufacturer's Service Information

Rolls-Royce plc has issued mandatory service bulletin (MSB) No. RB.211-72-C818, Revision 5, dated March 30, 2001, that specifies lower initial inspection thresholds, and repetitive ultrasonic inspections for cracks in fan blade dovetail roots, using either the blade root probe method, or the surface wave probe method. However, fan blades part numbers (P/N's) UL38052 and UL38628, are restricted to the root probe method only. Investigation by the manufacturer has shown that the surface wave probe method on these fan blades does not routinely detect cracking of this blade root design configuration. Also, this MSB Revision 5 adds the model RB211-524H-T-36 engine to the applicability.

Bilateral Airworthiness Agreement

These engine models are manufactured in the United Kingdom (UK) and 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 UK has kept the FAA informed of the situation described above. The FAA has examined the findings of the UK, 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.

FAA's Determination of an Unsafe Condition and Required Actions

Although none of these affected engine models are used on any airplanes that are registered in the United States, the possibility exists that the engine models could be used on airplanes that are registered in the United States in the future. Since an unsafe condition has been identified that is likely to exist or develop on other Rolls-Royce plc RB211-524G series and RB211-524H series turbofan engines of the same type design, this AD is being issued to detect cracked fan blades, which could result in an uncontained engine failure and damage to the airplane. This AD requires initial ultrasonic inspection at lower thresholds, and repetitive ultrasonic inspections, for cracks in fan blade dovetail roots, using either the blade root probe method or the surface wave probe method. This AD also adds the model RB211-524H-T-36 engine to the applicability. The actions are required to be done in accordance with the mandatory service bulletin described previously.

Immediate Adoption of This AD

Since there are currently no domestic operators of these engine models, notice and opportunity for prior public comment are unnecessary. Therefore, a situation exists that allows the immediate adoption of this regulation.

Comments Invited

Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the 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 that summarizes each FAA-public contact concerned with the substance of this AD 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 2000-NE-02-AD.” The postcard will be date stamped and returned to the commenter.

Regulatory Analysis

This final 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 final rule.

The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and is not a “significant regulatory action” under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, may be obtained from the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Incorporation by reference
• Safety

Adoption of the Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends 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 removing Amendment 39-11622 ( 65 FR 14207, March 16, 2000) and adding a new airworthiness directive, Amendment 39-12460, to read as follows:

2002-02-12 Rolls-Royce plc: Amendment 39-12460. Docket No. 2000-NE-02-AD. Supersedes AD 2000-05-12, Amendment 39-11622.

Applicability: This airworthiness directive (AD) is applicable to Rolls-Royce plc (RR) models RB211-524G2-19, RB211-524G2-T-19, RB211-524G3-19, RB211-524G3-T-19, RB211-524H2-19, RB211-524H2-T-19, RB211-524H-36, and RB211-524H-T-36 turbofan engines, with fan blades part numbers (P/N's) UL23061, UL25772, UL27253, UL29561, UL29573, UL30533, UL36245, UL38009, UL38052, or UL38628, installed. These engines are installed on, but not limited to Boeing 747-400 series and 767 series 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 (f) 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 detect cracked fan blades, which could result in an uncontained engine failure and damage to the airplane, do the following:

Initial Inspection

(a) Ultrasonically inspect for cracks in the dovetail slots of the fan blades using the Initial Inspection cycles-since-new (CSN) for Root Probe Method or Wave Probe Method, in accordance with EITHER paragraph 3.E. (Root Probe Method) OR 3.F. (Wave Probe Method) of the Accomplishment Instructions of RR service bulletin (SB) RB.211-72-C818, Revision 5, dated March 30, 2001 and using Table 1 of this AD:

Table 1.—Initial and Repetitive Inspection Compliance Times

Fan blade P/N's	For root probe method		For wave probe method
	Initial inspection	Repetitive inspection	Initial inspection	Repetitive inspection
(1) UL23061, UL25772, UL27253, UL29561, UL29573, UL30533	Within 6,500 CSN	Within 330 cycles-since-last-inspection (CSLI)	Within 6,500 CSN	Within 270 CSLI.
(2) UL36245, UL38009	Within 1,150 CSN	Within 290 CSLI	Within 1,150 CSN	Within 250 CSLI.
(3) UL38052, UL38628	Within 1,150 CSN	Within 290 CSLI	Not Allowed	Not Allowed.

(b) For fan blades P/N's UL38052 or UL38628 initially inspected using paragraph 3.F. of the Accomplishment Instructions of RR SB RB.211-72-C818, Revision 4, dated June 23, 2000, inspect the blades for cracks in accordance with paragraph 3.E. of the Accomplishment Instructions of RR SB RB.211-72-C818, Revision 5, dated March 30, 2001 using the cycles-since-last-inspection (CSLI) times specified in Table 2 of this AD:

Table 2.—Inspection CSLI for Fan Blades Inspected Using RR SB RB.211-72-C818, Revision 4, Dated June 23, 2000

Number of CSLI	Inspection interval after the effective date of this AD
(1) 290 to 500 CSLI	Within 100 cycles-in-service (CIS).
(2) 501 to 750 CSLI	Within 50 CIS.
(3) More than 750 CSLI	Within 25 CIS.

Additional Requirement When Both Engines of the Same Boeing 767 Airplane Have One or More Fan Blades P/N's UL38052 or UL38628 Installed

(c) For fan blades, P/N's UL38052 and UL38628 that are installed in both engines of the same Boeing 767 airplane, and that have accumulated more than 290 CSLI, ultrasonic-inspect blades of one engine for cracks within 25 CIS after the effective date of this AD in accordance with paragraph 3.E. of the Accomplishment Instructions of RR SB RB.211-72-C818, Revision 5, dated March 30, 2001.

Repetitive Inspections

(d) Thereafter, ultrasonically inspect for cracks in the dovetail slots of the fan blades using the Repetitive Inspection CSLI for Root Probe Method or Wave Probe Method, in accordance with EITHER paragraph 3.E. OR 3.F. of the Accomplishment Instructions of RR SB RB.211-72-C818, Revision 5, dated March 30, 2001 and using Table 1 of this AD.

Dispositioning of Cracked Fan Blades

(e) Before further flight, replace any fan blade that does not meet the acceptance criteria specified in paragraph 3.E or 3.F. of the Accomplishment Instructions of SB RR SB RB.211-72-C818, Revision 5, dated March 30, 2001.

Terminating Action

(f) Removal from service of fan blades P/N's UL23061, UL25772, UL27253, UL29561, UL29573, UL30533, UL36245, UL38009, UL38052, and UL38628, and replacement with serviceable fan blades with P/N's other than these P/N's constitutes terminating action for the inspection requirements of this AD.

Alternative Methods of Compliance

(g) 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 requests 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

(h) Special flight permits may be issued in accordance with §§ 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.

Documents That Have Been Incorporated By Reference

(i) The inspections must be done in accordance with Rolls-Royce plc Mandatory Service Bulletin No. RB.211-72-C818, Revision 5, dated March 30, 2001. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Rolls-Royce plc, PO Box 31, Derby, England; telephone: [phone]; fax: [phone]. Copies may be inspected, by appointment, at the FAA, New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA; or at the Office of the Federal Register, 800 North Capitol Street, NW, suite 700, Washington, DC.

Effective Date

(j) This amendment becomes effective on March 1, 2002.

Issued in Burlington, Massachusetts, on February 1, 2002.

Jay J. Pardee,

Manager, Engine and Propeller Directorate, Aircraft Certification Service.