AD 98-15-02

This amendment adopts a new airworthiness directive (AD) that is applicable to Rolls-Royce Limited, Aero Division-Bristol, S.N.E.C.M.A. Olympus 593 series turbojet engines. This action requires identifying reduced post-rebroaching cyclic life limits for certain rebroached stage 6 high pressure compressor (HPC) disks, inspecting the rebroached disks for cracks, and, if necessary, removing from service cracked disks. This amendment is prompted by reports of the low cyclic lives at which some rebroached stage 6 HPC disks have been found cracked. The actions specified in this AD are intended to prevent rebroached stage 6 HPC disk failure, which could result in an uncontained engine failure and damage to the aircraft.
The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of July 29, 1998.
Comments for inclusion in the Rules Docket must be received on or before September 14,
1998.

Final rule; request for comments.

98-15-02 Rolls-Royce Limited, Aero Division-Bristol, S.N.E.C.M.A.: Amendment 39-10653. Docket 98-ANE-13-AD.
Applicability: Rolls-Royce Limited (R-R), Aero Division-Bristol, S.N.E.C.M.A. Olympus 593 Mk. 610-14-28 turbojet engines, installed on but not limited to British Aerospace/Aerospatiale Concorde series aircraft.
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 (b) 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: Required as indicated, unless accomplished previously.
To prevent rebroached stage 6 high pressure compressor (HPC) disk failure, which could result in an uncontained engine failure and damage to the aircraft, accomplish the following:
(a) Accomplish the following in accordance with R-R Service Bulletin (SB) No. OL.593-72-9016-416, Revision 1, dated December 5, 1997:
(1) Remove from service rebroached HPC stage 6 disks (B509174 to B509181) listed in Table 1 and 5 of the SB prior to exceeding the earliest of the following:
(i) 1,100 cycles in service (CIS) since rebroaching, or
(ii) 2,700 cycles since new (CSN) prior to January 1, 2000, or
(iii) 2,500 CSN after December 31, 1999.
(2) Inspect the HPC stage 6 disks listed in Table 2 and 6 of the SB within the CIS intervals since rebroach as defined in these Tables. Disks with cracks in any blade root slot mustbe removed from service. Perform the inspection in accordance with R-R SB No. OL.593-72-8951-364, Revision 5, dated August 31, 1995.
(3) Remove from service HPC stage 6 disks listed in Table 2 and 6 of the SB prior to exceeding the maximum post-rebroach cyclic life limits as defined in these Tables, or 2,500 CSN after December 31, 1999, whichever occurs first.
(b) 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. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Engine Certification Office.
Note 2: Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the Engine Certification Office.
(c) Special flight permits may be issued in accordance with sections 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.
(d) The actions required by this AD shall be performed in accordance with the following R-R SB:

Document No.
Pages
Revision
Date
OL.593-72-9016-416
1-8
1
December 5, 1997
Total pages: 8.

OL.593-72-8951-364
1-9
5
August 31, 1995
Total pages: 9.

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, PO Box 3, Filton, Bristol BS12 7QE, England; telephone 01-17-979-1234, fax 01-17-979-7575. Copies may be inspected 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.
(e) This amendment becomes effective on July 29, 1998.

The Civil Aviation Authority (CAA), which is the airworthiness authority for the United Kingdom (UK), recently notified the Federal Aviation Administration (FAA) that an unsafe condition may exist on Rolls-Royce Limited (R-R), Aero Division-Bristol, S.N.E.C.M.A Olympus 593 Mk. 610-14-28 turbojet engines. The CAA advises that they have received reports of cracked, rebroached stage 6 high pressure compressor (HPC) disks. There are currently no affected engines operated on aircraft of U.S. registry. This AD, then, is necessary to require accomplishment of the required actions for engines installed on aircraft currently of foreign registry that may someday be imported into the U.S. or for engines installed on aircraft which currently operate in US airspace. Accordingly, the FAA has determined that notice and prior opportunity for comment are unnecessary and good cause exists for making this amendment effective in less than 30 days. This condition, if not corrected, could result in rebroached stage 6 HPC disk failure, which could result in an uncontained engine failure and damage to the aircraft.
R-R has issued Service Bulletin (SB) No. OL.593-72-9016-416, Revision 1, dated December 5, 1997, that specifies procedures for identifying the new, reduced, cyclic life limits for individual stage 6 HPC disks, and SB No. OL.593-72-8951-364, Revision 5, dated August 31, 1995, that specifies procedures for inspection of rebroached stage 6 HPC disks for cracks. The CAA classified these SBs as mandatory and issued AD 007-06-96 in order to assure the airworthiness of these engines in the UK.
This engine model is manufactured in the 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. Pursuant to this bilateral airworthiness agreement, the CAA has kept the FAA informed of the situation described above. The FAA has 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.
Since an unsafe condition has been identified that is likely to exist or develop on other engines of the same type design registered in the United States, this AD requires identifying reduced post-rebroaching cyclic life limits for rebroached stage 6 high pressure compressor (HPC) disks (B509174 to B509181), inspecting the rebroached disks for cracks, and if necessary, removing from service cracked disks. The actions would be required to be accomplished in accordance with the SBs described previously.
Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days. 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 notice must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket Number 98-ANE-13-AD." The postcard will be date stamped and returned to the commenter.
The regulations adopted herein will not have substantial direct effects 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. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.
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 adding the following new airworthiness directive: