The Civil Aviation Authority (CAA), which is the airworthiness authority for the United Kingdom (UK), notified the FAA that an unsafe condition may exist on Bae/SNIAS Concorde Type 1 airplanes with RR Olympus 593 Mk. 610-14-28 turbojet engines. The CAA advises that if the disks were not rebroached correctly, certain HPC stage 5 disks may fail to achieve their anticipated cyclic life limit before cracking. Service experience with HPC stage 6 disks that were rebroached using a similar process demonstrated that the disks failed to achieve the anticipated life limit before being rejected for cracks. Further investigation revealed that original cracks were not being removed by the rebroaching. Therefore, a review of the HPC stage 5 disks was done. The analysis indicated that certain HPC stage 5 disks needed to be inspected between specific cyclic intervals to ensure that they have no cracks and that they can then achieve their previously anticipated life. At the time the CAA AD was originally written, there were a number of uninspected disks. Currently, there are only two HPC stage 5 disks that have not been inspected.
Manufacturer's Service Information
RR has issued Olympus 593 MSB No. OL.593-72-8951-364, Revision 7, dated November 23, 2001, that specifies the inspection requirements for certain HPC stage 5 disks. The CAA classified this service bulletin as mandatory and issued AD 006-07-98 in order to ensure the airworthiness of these RR engines in the UK.
Differences Between the Manufacturers Service Information and This AD
RR has issued Olympus 593 MSB No. OL.593-72-9051-428, Revision 1, dated November 16, 2001, that requires disk P/N B510911, SN J14CA, to be inspected within 200 to 958 cycles-in-service (CIS) after rebroaching and disk P/N B510909, SN JZJ66, to be inspected within 200 to 931 CIS after rebroaching. However, since none of these engines are installed on airplanes of the U.S. registry, the FAA requires that they be inspected before further flight.
Bilateral Airworthiness Agreement
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.
FAA's Determination of an Unsafe Condition and Required Actions
Although none of these affected engine models are used on any airplanes that are registered in the United States, the possibility exists that the engine models could be used on airplanes that are registered in the United States in the future. Since an unsafe condition has been identified that is likely to exist or develop on other RR Olympus 593 Mk. 610-14-28 turbojet engines of the same type design, this AD is being issued to prevent failure of the HPC stage 5 disk, which could result in an uncontained engine failure and damage to the airplane. This AD requires a one-time fluorescent penetrant inspection (FPI) of certain rebroached HPC stage 5 disks, inspecting for cracks, and if necessary, removing cracked disks from service. The actions must be done in accordance with the service bulletin described previously.
Immediate Adoption of This AD
Since there are currently no domestic operators of this engine model, notice and opportunity for prior public comment are unnecessary. Therefore, a situation exists that allows the immediate adoption of this regulation.
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 action must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket Number 2002-NE-28-AD." The postcard will be date stamped and returned to the commenter.
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 this final rule.
The FAA has determined that this regulation is an emergency regulation that must beissued 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: