03-13221. Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG Models Tay 650-15 and 651-54 Turbofan Engines

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The Federal Aviation Administration (FAA) proposes to supersede an existing airworthiness directive (AD), applicable to Rolls-Royce Deutschland Ltd & Co KG (RRD) (formerly Rolls-Royce plc) models Tay 650-15 and 651-54 turbofan engines with certain part numbers of fan blades and fan discs. That AD currently requires initial and repetitive visual and ultrasonic inspections of fan blades for cracks, and, if necessary, replacement with serviceable parts. In addition, that AD requires recording instances when engines are operated in a stabilized manner in newly prohibited ranges. This proposal would also require recording instances when engines are operated inadvertently in reverse thrust in prohibited ranges, and would require before further flight initial and repetitive ultrasonic inspections of fan blades for cracks and if necessary, dispositioning of fan blades and fan discs, if certain reverse thrust events occurred. This proposal is prompted by updated prohibited ranges of engine operation and the introduction of an N1 Alert System in Fokker Model F.28 Mark 0100 airplanes with Tay 650-15 engines installed. The actions specified by the proposed AD are intended to prevent fan blade failures, which can result in an uncontained engine failure, engine fire, and damage to the airplane.

DATES:

Comments must be received by July 28, 2003.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 98-ANE-68-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.

The service information referenced in the proposed rule may be obtained from Rolls-Royce plc, Technical Publications Department, PO Box 31, Derby, England DE248BJ; telephone [phone], fax [phone]. This information may be examined, by appointment, at the FAA, New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA.

FOR FURTHER INFORMATION CONTACT:

James Lawrence, Aerospace Engineer, Aircraft 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 98-ANE-68-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. 98-ANE-68-AD, 12 New England Executive Park, Burlington, MA 01803-5299.

Discussion

On October 31, 2001, the FAA issued airworthiness directive (AD) 2001-22-18, Amendment 39-12497 (66 FR 56755, November 13, 2001), to require initial and repetitive visual and ultrasonic inspections of fan blades for cracks, and, if necessary, replacement with serviceable parts. In addition, that AD requires recording instances when Tay 650-15 engines are operated in a stabilized manner at any intermediate position between idle reverse and emergency maximum reverse thrust except during powerback operations. That AD also requires recording instances when Tay 651-54 engines are operated in a stabilized manner at any intermediate position between idle and maximum reverse thrust. The Luftfahrt-Bundesamt (LBA), which is the airworthiness authority for Germany, notified the FAA that an unsafe condition may exist on RRD models Tay 650-15 and 651-54 turbofan engines. The LBA advises that they have received reports of two separate Tay 650-15 low pressure (LP) compressor fan blade failures since 1997. The most recent failure occurred on September 15, 2001 and resulted in the release of the LP compressor assembly, penetration of the fuselage, and a fatality. Investigations indicate that fatigue cracks initiated in the fan blade root section due to fan flutter is caused by the engine operating in a stabilized manner between idle reverse thrust and emergency maximum reverse thrust for Tay 650-15 engines or between idle reverse thrust and maximum reverse thrust for Tay 651-54 engines. The airplane flight manuals have already been revised to prohibit operating in a stabilized manner within these ranges. However, inadvertent stabilized operations in the prohibited ranges could result in fan blade failure. This condition, if not corrected, could result in fan blade failure, which can result in an uncontained engine failure, engine fire, and damage to the airplane.

Since AD 2001-22-18 was issued, RRD has updated the prohibited ranges of engine operation regarding this condition for the models Tay 650-15 and 651-54 turbofan engines, by defining the conditions as to when inspections and dispositioning of fan blades and fan discs are required, based on whether or not an airplane-installed N1 alert system is used.

Manufacturer's Service Information

RRD has issued Service Bulletin (SB) Tay-72-1447, Revision 4, dated May 8, 2002, that describes procedures for recording engine operation within updated prohibited engine operating ranges, and specifies conditions for performing initial and repetitive ultrasonic inspections of fan blades. That SB also recognizes the introduction of Fokker SB F100-31-060, which installs an N1 Alert System in Fokker Model F.28 Mark 0100 airplanes. This N1 Alert System is designed to set a maintenance message that instructs inspection action if the engine is operated in prohibited operating ranges. The LBA classified this service bulletin as mandatory and issued AD No. 2002-090, dated May 8, 2002, in order to assure the airworthiness of these RRD Tay 650-15 and 651-54 turbofan engines in Germany.

Bilateral Agreement Information

These engine models are manufactured in the U.K. 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. However, the primary type certificates have been transferred from Rolls-Royce plc in the U.K. to Rolls-Royce Deutschland Ltd & Co KG in Germany. Pursuant to this bilateral airworthiness agreement, the LBA has kept the FAA informed of the situation described above. The FAA has examined the findings of the LBA, 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 RRD Tay 650-15 and 651-54 turbofan engines of the same type design that are used on airplanes registered in the United States, the proposed AD would require recording instances when engines are operated inadvertently in reverse thrust in prohibited ranges. The proposed AD would also require ultrasonic inspections of roots of Tay 650-15 fan blades, part numbers (P/Ns) JR31911, JR31912, JR33865, JR33866, JR35120, or JR35121, installed in fan discs P/N JR31198A, and of Tay 651-54 fan blades P/Ns JR31911, JR31912, JR33865, or JR33866, installed in fan discs P/N JR34563A, and if necessary, dispositioning of fan blades and fan discs, before further flight if certain reverse thrust events occur. The actions would be required to be done in accordance with the service bulletin described previously.

Economic Analysis

There are approximately 713 RRD Tay 650-15 and 651-54 engines of the affected design in the worldwide fleet. The FAA estimates that 451 engines installed on airplanes of U.S. registry would be affected by this proposed AD. Based on the current utilization and shop visit rates for the affected engine models, the FAA estimates that the number of shop visits and inspections for the U.S. fleet would be approximately 140 per year. It would take approximately 5 work hours per engine to do the actions at a labor rate of $60 per work hour. Assuming that five percent of these inspections result in a rejected fan blade set at a cost of approximately $100,000 per set, the annual cost of this proposed AD on U.S. operators is estimated to be $742,000. The current inspection failure rate is below one percent and this cost estimate is believed to be conservatively high.

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 removing Amendment 39-12497, (66 FR 56755), and by adding a new airworthiness directive:

Rolls-Royce plc: Docket No. 98-ANE-68-AD. Supersedes AD 2001-22-18, Amendment 39-12497.

Applicability: This airworthiness directive (AD) is applicable to Rolls-Royce plc (RR) models Tay 650-15 turbofan engines with fan blades, part numbers (P/Ns) JR31911, JR31912, JR33865, JR33866, JR35120, or JR35121, installed in fan discs P/N JR31198A, and Tay 651-54 turbofan engines with fan blades P/Ns JR31911, JR31912, JR33865, or JR33866, installed in fan discs P/N JR34563A. These engines are installed on, but not limited to Fokker Model F.28 Mark 0100 and Boeing 727-100 series airplanes modified in accordance with Supplemental Type Certificate (STC) SA8472SW (727-QF).

Note 1:

This airworthiness directive (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 fan blade failures, which can result in an uncontained engine failure, engine fire, and damage to the airplane, do the following:

Record Operation in Prohibited Operating Ranges

(a) If an engine is operated inadvertently in reverse thrust within the prohibited ranges described in RRD Service Bulletin (SB) No. Tay 72-1447, Revision 4, dated May 8, 2002, paragraph 1.C., as applicable by engine model, then before further flight make an entry in the engine records that reflects that operation. If known, include the stabilized N1 speed in the engine records.

Inspections

(b) Perform initial and repetitive ultrasonic inspections (UI) of fan blades each time an engine is operated inadvertently in reverse thrust within the prohibited ranges described in RRD SB No. Tay 72-1447, Revision 4, dated May 8, 2002, paragraph 1.C., as specified in the following Table 1:

Table 1.—Initial and Repetitive Inspection Criteria

Airplane and engine model	N1 Alert system status (installed per Fokker SB F100-31-060)	Was this a powerback event?	If inadvertent reverse thrust event was:	Then before next flight:
(1) Fokker 0100; Tay 650-15	(i) Installed and operative	(A) No	Between 57% and 75% N1 speed for 7.5 seconds or more	Perform UI and if necessary, disposition parts in accordance with paragraphs 3. and 3.A. of RR SB No. Tay 72-1447, Revision 4, dated May 8, 2002.
		(B) Yes	Between 57% and 75% N1 speed for 7.5 seconds or more	Perform UI and if necessary, disposition parts in accordance with paragraphs 3. and 3.B. of RR SB No. Tay 72-1447, Revision 4, dated May 8, 2002.
	(ii) Not installed, or installed but not operative	(A) No	N1 above idle for any reason	Perform UI and if necessary, disposition parts in accordance with paragraphs 3. and 3.A. of RR SB No. Tay 72-1447, Revision 4, dated May 8, 2002, unless it can be proven by flight data recorder information that engine operation between 57% and 75% N1 speed lasted less than 7.5 seconds.
		(B) Yes	Between 57% and 75% N1 speed	Perform UI and if necessary, disposition parts in accordance with paragraphs 3. and 3.B. of RR SB No. Tay 72-1447, Revision 4, dated May 8, 2002, unless it can be proven by flight data recorder information that engine operation between 57% and 75% N1 speed lasted less than 7.5 seconds.
(2) Boeing 727-QF; Tay 651-54	Not applicable	Not applicable	Between 57% and 75% N1 speed for 7.5 seconds or more, or if the parameters cannot be confirmed	Perform UI and if necessary, disposition parts in accordance with paragraphs 3. and 3.A. of RR SB No. Tay 72-1447, Revision 4, dated May 8, 2002.

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 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.

Note 3:

The subject of this AD is addressed in Luftfahrt-Bundesamt airworthiness directive No. 2002-090, dated May 8, 2002.

Issued in Burlington, Massachusetts, on May 20, 2003.

Francis A. Favara,

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