Federal Aviation Administration, DOT.
Notice of proposed rulemaking (NPRM).Start Printed Page 30342
The Federal Aviation Administration (FAA) proposes to revise an existing airworthiness directive (AD), applicable to CFE Company Model CFE738-1-1B turbofan engines. That AD currently requires a one-time visual inspection of Stage 2 high pressure turbine (HPT) aft cooling plates for nicks, dents, raised metal, and scratches, and if necessary, repair of the cooling plates or replacement with serviceable parts. This proposal is prompted by an updated alert service bulletin (ASB) that reduces the number of stage 2 HPT aft cooling plates affected by this AD and identifies the applicable engines by engine serial numbers (SN's). In the event that the affected gas generator modules containing the affected parts have been transferred to another engine, the SN's of those gas generator modules have been added to this AD. The actions specified by the proposed AD are intended to prevent stage 2 HPT aft cooling plate failure, which could result in an uncontained engine failure and damage to the airplane.
Comments must be received by August 6, 2001.
Submit comments in triplicate to the Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 99-NE-39-AD, 12 New England Executive Park, Burlington, MA 01803-5299. Comments may also be sent via the Internet using the following address: “email@example.com.” Comments sent via the Internet must contain the docket number in the subject line. Comments may be inspected at this location between 8:00 a.m. and 4:30 p.m., Monday through Friday, except Federal holidays.
The service information referenced in the proposed rule may be obtained from CFE Company, Data Distribution, MS 64-03/2101-201, P.O. Box 29003, Phoenix, AZ 85038-9003; telephone (602) 365-2493, fax (602) 365-5577. This information may be examined at the FAA, New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA.Start Further Info
FOR FURTHER INFORMATION CONTACT:
Keith Mead, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; telephone: (781) 238-7744, fax: (781) 238-7199.End Further Info End Preamble Start Supplemental Information
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 99-NE-39-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. 99-NE-39-AD, 12 New England Executive Park, Burlington, MA 01803-5299.
On December 29, 1999, the FAA issued AD 99-27-16, Amendment 39-11497 (65 FR 691, January 6, 2000), to require a one-time visual inspection of 72 Stage 2 HPT aft cooling plates for nicks, dents, raised metal, and scratches. If any nicks, dents, raised metal, or scratches were found, that AD also required repair of the cooling plates or replacement with serviceable parts. That action was prompted by reports of Stage 2 HPT aft cooling plates that were dented during the assembly of the cooling plate to the Stage 2 disk due to raised metal on the stage 2 HPT disk post aft mating surface. The raised metal condition on the stage 2 HPT disk post was caused by an improperly installed locating pin in the assembly tool. That condition, if not corrected, could result in HPT aft cooling plate failure, which could result in an uncontained engine failure and damage to the airplane. Since AD 99-27-16 was issued, CFE Company has isolated the observed assembly damage to a known replacement of the locating pin in the assembly tooling. It has been determined that only ten of the original 72 HPT cooling plate/stage 2 disk assemblies were assembled before tool correction occurred. Records show these ten HPT cooling plate/stage 2 disk assemblies were subsequently assembled in ten gas generator modules, S/N's 800421-800430. These gas generator modules, along with the engines on which these modules were installed, are listed in this AD.
Manufacturer's Service Information
The FAA has reviewed and approved the technical contents of CFE Company Alert Service Bulletin (ASB) CFE738-A72-8031, Revision 2, dated October 17, 2000, that describes the dimensional inspection procedures for indentation depth on stage 2 HPT aft cooling plates, inspection of the stage 2 HPT rotor disk for raised metal, and the acceptance and repair criteria of the stage 2 HPT aft cooling plate and HPT rotor disk.
Differences Between This AD and the Manufacturer's Service Information
Although ASB CFE738-A72-8031, Revision 2, dated October 17, 2000, identifies ten engines by SN, the FAA is also listing the ten gas generator module SN's in which the affected HPT cooling plate/stage 2 HPT disk assemblies are installed. This listing is made to assure that the gas generator modules containing the affected parts are identified and inspected regardless of which engine they are installed on. Gas generator modules may not necessarily stay installed in one and only one engine.
FAA's Determination of an Unsafe Condition and Proposed Actions
Since an unsafe condition has been identified that is likely to exist or develop on other products of this same type design, the proposed AD would require, on gas generator modules identified by SN, a one-time visual inspection of stage 2 HPT aft cooling plates for nicks, dents, raised metal, and scratches, and if present, replacement with serviceable parts, or, dimensional inspection of indentation depth, repair if indentation is within acceptable limits, and if not, replacement with serviceable parts. This AD would also require inspection of the stage 2 HPT rotor disk post aft surface which mates with the stage 2 HPT aft cooling plate, for raised metal, and, removal of the raised metal, if present, or replacement with a serviceable part. The inspections would be required at the next shop visit Start Printed Page 30343after the effective date of this AD where the HPT assembly is sufficiently disassembled to afford access to the stage 2 HPT aft cooling plate, but not later than 4,500 part cycles-since-new (CSN) in accordance with the ASB described previously.
There are approximately ten engines of the affected design in the worldwide fleet. The FAA estimates that nine engines installed on airplanes of US registry would be affected by this proposed AD, that it would take approximately four work hours per engine to accomplish the proposed inspection if the inspection did not take place during scheduled maintenance, and that the average labor rate is $60 per work hour. Required parts would cost approximately $1,536 per engine. Based on these figures, the total cost impact of the proposed AD on US operators is estimated to be $15,484.
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.Start List of Subjects
List of Subjects in 14 CFR Part 39
- Air transportation
- Aviation safety
Adoption of the 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:Start Part
PART 39—AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
2. Section 39.13 is amended by removing Amendment 39-11497 (65 FR 691, January 6, 2000), and by adding a new airworthiness directive, to read as follows:
CFE Company: Docket No. 99-NE-39-AD.
Revises AD 99-27-16, Amendment 39-11497.
This airworthiness directive (AD) is applicable to CFE Model CFE738-1-1B turbofan engines, part number (P/N) 3050000-5, with gas generator modules P/N 6091T09G01, serial numbers (SN's) 800421, 800422, 800423, 800424, 800425, 800426, 800427, 800428, 800429, and 800430 installed. These modules are currently installed in engine SN's 105323, 105324, 105325, 105326, 105328, 105329, 105331, 105332, 105333, and 105392. These engines are installed on, but not limited to Dassault-Breguet Falcon 2000 series airplanes.
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 (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 with this AD is required as indicated, unless already done.
To prevent stage 2 high pressure turbine (HPT) aft cooling plate failure, which could result in an uncontained engine failure and damage to the airplane, accomplish the following:
Inspections and Follow-On Actions
(a) At the next engine shop visit after the effective date of this AD where the HPT assembly is sufficiently disassembled to afford access to the Stage 2 HPT aft cooling plate, but not later than 4,500 part cycles-since-new (CSN), accomplish the following:
(1) Inspect the stage 2 HPT aft cooling plate for nicks, dents, and scratches on surface D in accordance with the requirements of CFE Alert Service Bulletin (ASB) No. CFE738-A72-8031, Revision 2, dated October 17, 2000, paragraph 2.B.(1).
(2) Repair those stage 2 HPT aft cooling plates with indentation 0.003 inch deep or less in accordance with ASB No. CFE738-A72-8031, Revision 2, dated October 17, 2000, paragraph 2.B.(1).
(3) Remove from service prior to further flight those stage 2 HPT aft cooling plates that have nicks, dents, and/or scratches that exceed the acceptance limits in accordance with ASB No. CFE738-A72-8031, Revision 2, dated October 17, 2000, paragraph 2.B.(1), and replace with serviceable parts.
(4) Inspect the stage 2 HPT rotor disk post aft mating surface for raised metal, and remove raised metal if present in accordance with ASB No. CFE738-A72-8031, Revision 2, dated October 17, 2000, paragraph 2.B.(2).
Alternative Methods of Compliance
(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 (ECO). Operators shall submit their request through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, ECO.
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
(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 airplane to a location where the inspection requirements of this AD can be accomplished.
Issued in Burlington, Massachusetts, on May 25, 2001.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification Service.
[FR Doc. 01-14146 Filed 6-5-01; 8:45 am]
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