E7-20999. Airworthiness Directives; Rolls-Royce plc RB211 Series Turbofan Engines

AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT).

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to supersede an existing airworthiness directive (AD) for Rolls-Royce plc (RR) RB211-535E4-37, RB211-535E4-B-37, and RB211-535E4-B-75 series turbofan engines. That AD requires initial and repetitive ultrasonic inspections of installed low pressure compressor (LPC) fan blade roots on-wing and during overhaul, and relubrication according to accumulated life cycles. That AD also introduces an alternative technique to ultrasonically inspect installed fan blades on-wing using a surface wave ultrasonic probe. Also, that AD introduces application of Metco 58 blade root coating as an optional terminating action. This proposed AD would require the same actions but would add compliance paragraphs to relax the compliance schedule for repetitive inspections for RB211-535E4 engines operating in flight profiles A and B, if certain requirements are met. This proposed AD results from RR issuing Mandatory Service Bulletin (MSB) No. RB.211-72-C879, Revision 5. That MSB introduces a relaxed repetitive compliance schedule for RB211-535E4 engines operating in flight profiles A and B, if certain requirements are met. We are proposing this AD to detect cracks in LPC fan blade roots, which if not detected, could lead to uncontained multiple fan blade failure, and damage to the airplane.

DATES:

We must receive any comments on this proposed AD by December 24, 2007.

ADDRESSES:

Use one of the following addresses to comment on this proposed AD.

• Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
• Mail: Docket Management Facility, U.S. Department of Transportation, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590-0001.
• Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.
• Fax: [phone].

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

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; e-mail: [e-mail]; telephone: [phone]; fax: [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send us any written relevant data, views, or arguments regarding this proposal. Send your comments to an address listed under ADDRESSES. Include “Docket No. FAA-2007-29343; Directorate Identifier 2000-NE-13-AD” in the subject line of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments received by the closing date and may amend the proposed AD in light of those comments.

We will post all comments we receive, without change, to http://www.regulations.gov,, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this proposed AD. Using the search function of the Web site, anyone can find and read the comments in any of our dockets, including, if provided, the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78).

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.gov;​; or in person at the Docket Operations office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Operations office (telephone [phone]) is the same as the Mail address provided in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

Discussion

On January 18, 2005, we issued AD 2005-02-05, Amendment 39-13950 (70 FR 3863, January 27, 2005). That AD requires initial and repetitive ultrasonic inspections of installed LPC fan blade roots on-wing and during overhaul using a surface wave ultrasonic probe, and relubrication according to accumulated life cycles. That AD also adds the application of Metco 58 blade root coating as an optional terminating action. That AD results from RR issuing MSB No. RB.211-72-C879, Revision 4, which contains revised Accomplishment Instructions and consumable materials list.

Actions Since We Issued AD 2005-02-05

Since we issued AD 2005-02-05, Rolls-Royce plc updated MSB No. RB.211-72-C879, Revision 4, dated April 2, 2004, to Revision 5, dated March 8, 2007, for RR RB211 series turbofan engines. Revision 5 relaxes the compliance for repetitive inspections for RB211-535E4 engines operating in flight profiles A and B, if certain requirements are met.

Clarification Changes

Also, as clarification, we changed the Table 4 initial compliance from “65% hard life” to “within 350 cycles after achieving 65% hard life”. These changes better reflect the proposed AD wording, with the latest MSB.

Relevant Service Information

We have reviewed and approved the technical contents of Rolls-Royce plc MSB No. RB.211-72-C879, Revision 5, dated March 8, 2007. That MSB describes procedures for ultrasonic inspection of high cyclic life blades on-wing with either the LPC fan blades in place or removed from the LPC. The Civil Aviation Authority (CAA), which is the airworthiness authority for the United Kingdom (UK), classified the original issue of the service bulletin as mandatory and issued AD 002-01-2000 to ensure the airworthiness of these RR engines in the UK.

Bilateral Agreement Information

This engine model is manufactured in UK 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 UK kept us 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 of 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 initial and repetitive ultrasonic inspection of installed LPC fan blade roots on-wing and during overhaul using a surface wave ultrasonic probe, and relubrication according to accumulated life cycles. This proposed AD would also maintain the application of Metco 58 blade root coating as an optional terminating action. The proposed AD would require that you do these actions using the service information described previously.

Costs of Compliance

We estimate that this proposed AD would affect 788 engines installed on airplanes of U.S. registry. We also estimate that it would take about 7 work-hours per engine to perform the proposed actions, and that the average labor rate is $80 per work-hour. Based on these figures, we estimate the total cost of the proposed AD to U.S. operators to be $358,540.

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 AD:

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 regulatory evaluation of the estimated costs to comply with this proposed AD. See the ADDRESSES section for a location to examine the regulatory evaluation.

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 39-13950 (70 FR 3863, January 27, 2005) and by adding a new airworthiness directive, to read as follows:

Rolls-Royce plc: Docket No. FAA-2007-29343; Directorate Identifier 2000-NE-13-AD.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by December 24, 2007.

Affected ADs

(b) This AD revises AD 2005-02-05, Amendment 39-13950.

Applicability

(c) This AD applies to Rolls-Royce plc (RR) RB211-535E4-37, RB211-535E4-B-37, and RB211-535E4-B-75 series turbofan engines with low pressure compressor (LPC) fan blades with the part numbers (P/Ns) listed in Table 1 of this AD. These engines are installed on, but not limited to, Boeing 757 and Tupolev Tu204 series airplanes. Table 1 follows:

Table 1.—Applicable LPC Fan Blade P/Ns

UL16135	UL16171	UL16182	UL19643	UL20044
UL20132	UL20616	UL21345	UL22286	UL23122
UL24525	UL24528	UL24530	UL24532	UL24534
UL27992	UL28601	UL28602	UL29511	UL29556
UL30817	UL30819	UL30933	UL30935	UL33707
UL33709	UL36992	UL37090	UL37272	UL37274
UL37276	UL37278	UL38029	UL38032

Unsafe Condition

(d) This AD results from RR issuing Mandatory Service Bulletin (MSB) No. RB.211-72-C879, Revision 5, that introduces a relaxed repetitive compliance schedule for RB211-535E4 engines operating in flight profiles A and B, if certain requirements are met. We are issuing this AD to detect cracks in low pressure compressor (LPC) fan blade roots, which if not detected, could lead to uncontained multiple fan blade failure, and 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.

(f) If you have a full set of fan blades, modified using RR Service Bulletin No. RB.211-72-C946, Revision 2, dated September 26, 2002, that can be identified by a blue triangle etched on the blade airfoil suction surface close to the leading edge tip of each blade, no further action is required.

(g) On RB211-535E4 engines, operated to Flight Profile A, ultrasonically inspect, and if required, relubricate using the following Table 2:

Table 2.—RB211-535E4 Flight Profile A

Engine location	Initial inspection within cycles-since-new (CSN)	Type action	In accordance with mandatory service bulletin (MSB)	Repeat inspection within (CSN)
(1) On-wing	17,350	(i) Root Probe, inspect and relubricate, OR	RB.211-72-C879 Revision 5, 3.A.(1) through 3.A.(7), dated March 8, 2007	1,400
		(ii) Wave Probe	RB.211-72-C879 Revision 5, 3.B.(1) through 3.B.(7), dated March 8, 2007	1,150
(2) In Shop	17,350	Root Probe, inspect and relubricate	RB.211-72-C879 Revision 5, 3.C.(1) through 3.C.(4), dated March 8, 2007	1,400

(h) On RB211-535E4 engines, operated to Flight Profile B, ultrasonically inspect, and if required, relubricate using the following Table 3:

Table 3.—RB211-535E4 Flight Profile B

Engine location	Initial inspection within (CSN)	Type action	In accordance with MSB	Repeat inspection within (CSN)
(1) On-wing	12,350	(i) Root Probe, inspect and relubricate, OR	RB.211-72-C879 Revision 5, 3.A.(1) through 3.A.(7), dated March 8, 2007.	850
		(ii) Wave Probe	RB.211-72-C879 Revision 5, 3.B.(1) through 3.B.(7), dated March 8, 2007	700
(2) In Shop	12,350	Root Probe, inspect and relubricate	RB.211-72-C879 Revision 5, 3.C.(1) through 3.C.(4), dated March 8, 2007	850

(i) On RB211-535E4 engines, operated to combined Flight Profile A and B, ultrasonically inspect, and if required, relubricate using the following Table 4:

Table 4.—RB211-535E4 Flight Profile A and B

Engine location	Initial inspection within (CSN)	Type action	In accordance with MSB	Repeat inspection within (CSN)
(1) On-wing	350 cycles after achieving 65% hard life (To calculate, see MSB Compliance Section 1.C.(4))	(i) Root Probe, inspect and relubricate, OR	RB.211-72-C879 Revision 5, 3.A.(1) through 3.A.(7), dated March 8, 2007	As current flight profile. See paragraphs (j) and (k) of this AD.
		(ii) Wave Probe	RB.211-72-C879 Revision 5, 3.B.(1) through 3.B.(7), dated March 8, 2007	As current flight profile. See paragraphs (j) and (k) of this AD.
(2) In Shop	350 cycles after achieving 65% hard life (To calculate, see MSB Compliance Section 1.C.(4))	Root Probe, inspect and relubricate	RB.211-72-C879 Revision 5, 3.C.(1) through 3.C.(4), dated March 8, 2007	As current flight profile. See paragraphs (j) and (k) of this AD.

(j) For RB.211-535E4 engines that are currently flying in Profile A, if the initial inspection is completed before X minus 1,400 cycles then the next inspection may be delayed to X, where X is 65% of the revised life limit.

(k) For RB.211-535E4 engines that are currently flying in Profile B, if the initial inspection is completed before X minus 850 cycles then the next inspection may be delayed to X, where X is 65% of the revised life limit.

(l) Fan blades that have been operated within RB.211-535E4 Flight Profile A and B will have final life as defined in the Time Limits Manual. See References Section 1.G.(3), of MSB RB.211-72-C879, Revision 5, dated March 8, 2007.

(m) On RB.211-535E4-B engines, ultrasonically inspect, and if required, relubricate using the following Table 5:

Table 5.—RB211-535E4-B

Engine location	Initial inspection within (CSN)	Type action	In accordance with MSB	Repeat inspection within (CSN)
(1) On-wing	17,000	(i) Root Probe, inspect and relubricate, OR	RB.211-72-C879 Revision 5, 3.A.(1) through 3.A.(7), dated March 8, 2007	1,200
		(ii) Wave Probe	RB.211-72-C879 Revision 5, 3.B.(1) through 3.B.(7), dated March 8, 2007	1,000
(2) In Shop	17,000	Root Probe, inspect and relubricate	RB.211-72-C879 Revision 5, 3.C.(1) through 3.C.(4), dated March 8, 2007	1,200

Optional Terminating Action

(n) Application of Metco 58 blade root coating using RR SB No. RB.211-72-C946, Revision 2, dated September 26, 2002, constitutes terminating action to the repetitive inspection requirements specified in paragraphs (g), (h), (i), and (k) of this AD.

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.

Previous Credit

(p) Previous credit is allowed for initial and repetitive inspections performed using AD 2003-12-15 (Amendment 39-13200, 68 FR 37735, June 25, 2003), RR MSB No. RB.211-72-C879, Revision 3, dated October 9, 2002, and RR MSB No. RB.211-72-C879, Revision 4, dated April 2, 2004.

Related Information

(q) CAA airworthiness directive AD 002-01-2000, dated October 9, 2002, also addresses the subject of this AD.

Issued in Burlington, Massachusetts, on October 18, 2007.

Francis A. Favara,

Manager, Engine and Propeller Directorate, Aircraft Certification Service.