AD 2001-22-18

This amendment adopts a new airworthiness directive (AD), that is applicable to Rolls-Royce, plc models Tay 650-15 and 651-54 turbofan engines. This amendment requires initial and repetitive visual and ultrasonic inspections of fan blades for cracks, and, if necessary, replacement with serviceable parts. In addition, this AD requires recording instances when engines are operated in a stabilized manner in newly prohibited ranges. This amendment is prompted by reports of fan blade failures. The actions specified by this AD are intended to prevent fan blade failures, which can result in an uncontained engine failure, engine fire, and damage to the airplane.

Final rule.

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

Applicability: This airworthiness directive (AD) is applicable to Rolls-Royce, plc (R-R) models Tay 650-15 and 651-54 turbofan engines. These engines are installed on, but not limited to, Fokker Model F.28 Mark 0100 and Boeing 727-QF 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 (e) 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, therequest should include specific proposed actions to address it.

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

To prevent fan blade failure, which can result in an uncontained engine failure, engine fire, and damage to the airplane, accomplish the following:

Record Operation in Prohibited Operating Ranges

(a) If an engine is operated in a stabilized manner within the prohibited ranges described in R-R Service Bulletin (SB) No. Tay-72-1447, Revision 2, dated July 25, 2000, paragraphs 3.A ., 3.B.(2), or 3.C. as applicable by engine model, then prior to the next 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 inspections of fan blades in accordance with paragraphs 1. D. (1) through (7) of R-R SB No. Tay 72-1442, Revision 1, dated December 19, 1997, as follows:

(1) Perform the initialinspection at the earliest of the following:

(i) If the engine records indicate that any of the conditions described in R-R SB No. Tay-72-1447, Revision 2, dated July 25, 2000, paragraphs 3.A.(2), 3.A.(3), 3.B.(2)(a), 3.B.(2)(b), or 3.C.(2), as applicable by engine model, are satisfied;

(ii) Prior to entering in service if fan blades are installed in a different engine than that from which they were removed and if the fan blades have time-in-service since the last inspection in accordance with R-R SB No. Tay 72-1442;

(iii) The next shop visit after the effective date of this AD.

(2) Thereafter, inspect at intervals not to exceed the earliest of paragraphs (b)(1)(i) through (b)(1)(iii) of this AD.

(c) Remove the entire fan blade set from service if any blade shows crack indications and replace with serviceable parts.

Definition of Shop Visit

(d) For the purposes of this AD, a shop visit is defined as the introduction of the engine into a shop that has the capability to separate Rolls-Royce, plc models Tay 650-15 or 651-54 turbofan engine major case flanges. This definition excludes shop visits when only field maintenance type activities are performed in lieu of performing them on-wing.

Alternative Methods of Compliance

(e) 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

(f) Special flight permits may be issued in accordance Secs. 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the aircraft to a location where the requirements of this AD can be accomplished.

Documents That Have Been Incorporated By Reference

(g) The inspection must be done in accordance with the following Rolls-Royce plc, mandatory service bulletins (MSB's):

Document No.
Pages
Revision
Date
MSB Tay 72-1442
1-3
1
December 19, 1997.
Appendix 1
1-2
3
1
Original
December 19, 1997.
October 31, 1997.
Appendix 2
1
1
December 19, 1997.
Appendix 3
1
1
December 19, 1997.
Appendix 4
1
Original
October 31, 1997.
Total pages: 9

MSB Tay-72-1447
1-5
2
July 25, 2000.
Total pages: 5

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, Technical Publications Department, PO Box 31, Derby, England DE248BJ; telephone 44 1332 242424; fax 44 1332 249936. 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.

Note 3: The subject of this AD is addressed in United Kingdom Civil Aviation Authority Airworthiness Directives 008-10-97 and 001-12-97.

Effective Date

(h) This amendment becomes effective on December 18, 2001.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that is applicable to Rolls-Royce, plc models Tay 650-15 and 651-54 turbofan engines was published in the Federal Register on September 14, 2000 (65 FR 55468). That action proposed to require initial and repetitive visual and ultrasonic inspections of fan blades for cracks, and, if necessary, replacement with serviceable parts. In addition, that action proposed to require recording instances when engines are operated in a stabilized manner in newly prohibited ranges.

Comments

Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received.

Possible Conflict of AD's

One commenter states that AD 98-06-07, which was issued by the Transport Airplane Directorate, conflicts with the proposed AD. The commenter requests that the FAA clarify its position regarding the removal of engine speed restrictions in the forward thrust mode, introduced by AD 98-06-07. The commenter notes that the proposed AD does not require inspections if engines are operated in the restricted engine forward thrust mode, introduced by AD 98-06-07. The commenter appears to believe that the proposed action will have the effect of removing the restrictions introduced by AD 98-06-07. The FAA does not agree.

This AD is based on the latest revisions of service information published by the engine manufacturer, Rolls-Royce. Based on that information, the FAA has determined that no inspections are necessary for engines operated in the restricted engine forward thrust mode, introduced by AD 98-06-07. AD 98-06-07 was issued by the Transport Airplane Directorate. The Engine & Propeller Directorate has informed the Transport Airplane Directorate of this finding, which the Transport Directorate may use as a basis for further rulemaking with regard to the requirements of AD 98-06-07. The FAA believes, however, that this AD and AD 98-07-06 do not conflict in that it is possible for operaters to comply with both AD's. Also, as stated by the commenter, an approval for modification of the requirements of AD 98-06-07 can be pursued through a request for an alternative method of compliance.

Modify Shop Visit Definition

One commenter requests that the shop visit definition in the proposed AD be modified to exclude engines that are inducted into the shop solely for convenience in performing maintenance that could be performed on-wing. The commenter further states that engines do not need to be removed from the airplane and inducted into the shop to perform on-wing types of maintenance, and, if only field-level maintenance is performed off-wing, it should not be considered a shop visit. The FAA agrees.

The intent of this proposed AD is to perform fan blade inspections during shop visit for heavy engine maintenance. Requiring these inspections during shop visits that are only performing field-level maintenance would needlessly penalize an operator when the required maintenance could be performed on-wing. Therefore, the FAA has revised the definition of shop visit to exclude those shop visits when only field maintenance type activities are performed in lieu of performing them on-wing.

After careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule with the changes described previously. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.

Economic Analysis

There are approximately 713 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 AD. Based on the current utilization and shop visit rates for the affected engine models, the FAAestimates 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 accomplish 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 impact of this 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 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 thisfinal rule.

For the reasons discussed above, I certify that this action (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 final evaluation has been prepared for this action and it 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, 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 part39) 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.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding a new airworthiness directive to read as follows: