E6-4922. Airworthiness Directives; Rolls-Royce plc Model RB211 Trent 892, 884, 877, 875, and 892B Series Turbofan Engines

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM); rescission.

SUMMARY:

The FAA proposes to rescind an existing airworthiness directive (AD) for Rolls-Royce plc (RR) Model RB211 Trent 892, 884, 877, 875, and 892B series turbofan engines. That AD currently requires inspecting and replacing certain angle gearbox and intermediate gearbox hardware, and on-going repetitive inspections of the magnetic chip detectors. This action would rescind all the requirements of AD 97-06-13, Amendment 39-9970, Docket No. 97-ANE-09. This proposed rescission results from the FAA determining that the inspections and replacements required by that AD are no longer required to correct an unsafe condition. Operators should, however, incorporate those inspections and replacements into their normal maintenance practices.

DATES:

We must receive any comments on this proposed AD rescission by June 5, 2006.

ADDRESSES:

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

• By mail: Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 97-ANE-09-AD, 12 New England Executive Park, Burlington, MA 01803.
• By fax: [phone].
• By e-mail: [e-mail].

You may examine the AD docket, by appointment, at the FAA, New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA.

FOR FURTHER INFORMATION CONTACT:

Christopher Spinney, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or arguments regarding this proposal. Send your comments to an address listed under ADDRESSES. Include “AD Docket No. 97-ANE-09” in the subject line of your comments. If you want us to acknowledge receipt of your mailed comments, send us a self-addressed, stamped postcard with the docket number written on it; we will date-stamp your postcard and mail it back to you. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. If a person contacts us verbally, and that contact relates to a substantive part of this proposed AD, we will summarize the contact and place the summary in the docket. We will consider all comments received by the closing date and may amend the proposed AD rescission in light of those comments.

Examining the AD Docket

You may examine the AD Docket (including any comments and service information), by appointment, between 8 a.m. and 4:30 p.m., Monday through Friday, except Federal holidays. See ADDRESSES for the location.

Discussion

On April 14, 1997, we issued AD 97-06-13, Amendment 39-9970, Docket No. 97-ANE-09 (62 FR 23339, April 30, 1997), for RR Model RB211 Trent 892, 884, 877, 875, and 892B series turbofan engines. That AD requires inspecting and replacing certain angle gearbox and intermediate gearbox hardware, and on-going repetitive inspections of the magnetic chip detectors on Trent 800 series engines.

Actions Since Issuing AD 97-06-13

Since issuing AD 97-06-13, we issued a notice of proposed rulemaking (NPRM) on October 25, 1999, to revise the AD to include additional optional terminating action to the gearbox hardware inspections, and to extend the intervals for the magnetic chip detector inspections. The Trent 800 fleet has grown in size and matured in fleet experience. Based on the current Trent 800 fleet and the service experience demonstrated since we published the AD and NPRM, the underlying unsafe conditions no longer justify that AD.

FAA's Conclusions

After reviewing the available data, we determined it is appropriate to rescind AD 97-06-13 to eliminate the mandate to perform inspections and hardware replacements. The inspections and hardware replacements are no longer required to correct an unsafe condition. Operators should however, incorporate those inspections and replacements into their normal maintenance schedules. Our determination is based on the following:

We based AD 97-06-13 on a determination of unsafe conditions on a fleet of engines that had a total operating experience of 29,000 hours. Today's fleet of engines has over 1.6 million operating hours, with a basic in-flight shutdown rate of well below acceptable levels. Fleet experience does not support the original unsafe condition determination.

The Civil Aviation Authority (CAA), which is the airworthiness authority for the United Kingdom, determined that their AD on the subject is no longer needed. They withdrew their AD, and they recommend we do likewise. Rolls-Royce plc, with CAA approval, withdrew the inspection service bulletins referenced in the AD. The fleet has completely incorporated the modifications required by AD 97-06-13, intended to prevent oil leaks.

This proposed action would rescind AD 97-06-13. Rescission of AD 97-06-13 would constitute only such action and if followed by a final action would not preclude the agency from issuing another action in the future nor would it commit the agency to any course of action in the future.

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 rescission would not have federalism implications under Executive Order 13132. This proposed rescission 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 rescission:

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.

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 the following airworthiness directive (AD):

Roll-Royce plc: Docket No. 97-ANE-09; AD 97-06-13; Amendment 39-9970.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this AD rescission by June 5, 2006.

Affected ADs

(b) This document rescinds AD 97-06-13.

Applicability

(c) This AD rescission applies to Rolls-Royce plc Model RB211 Trent 892, 884, 877, 875, and 892B series turbofan engines.

Issued in Burlington, Massachusetts, on March 30, 2006.

Peter A. White,

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