05-12414. Airworthiness Directives; Turbomeca Artouste III Series Turboshaft Engines

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to supersede an existing airworthiness directive (AD) for Turbomeca Artouste III series turboshaft engines. That AD currently requires smoke emission checks after every ground engine shutdown, and if necessary, additional checks and possibly removing the engine from service. That action also requires inspection of central labyrinths not previously inspected, or not replaced after the engine logged 1,500 operating hours, and, replacement if necessary. That action also requires the removal of injection wheels at a new lower life limit. This proposed AD includes the same requirements as the existing AD, but reduces the compliance time for the initial inspection of the central labyrinth and adds repetitive inspections of the central labyrinth. This proposed AD results from reports and analyses of in-flight engine shutdowns occurring since we issued AD 2002-22-11. We are proposing this AD to prevent injection wheel cracks and excessive central labyrinth wear, which could result in an in-flight engine shutdown.

DATES:

We must receive any comments on this proposed AD by August 22, 2005.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 99-NE-33-AD, 12 New England Executive Park, Burlington, MA 01803-5299. Comments may be inspected at this location, by appointment, between 8 a.m. and 4:30 p.m., Monday through Friday, except Federal holidays. Comments may also be sent via the Internet using the following address: [e-mail]. Comments sent via the Internet must contain the docket number in the subject line.

Contact Turbomeca S.A., 40220 Tarnos, France; telephone [phone], fax [phone], for the service information identified in this proposed AD.

FOR FURTHER INFORMATION CONTACT:

Christopher Spinney, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

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-33-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-33-AD, 12 New England Executive Park, Burlington, MA 01803-5299.

Discussion

On October 28, 2002, the FAA issued AD 2002-22-11, Amendment 39-12937 (67 FR 68022, November 8, 2002). That AD requires smoke emission checks after every ground engine shutdown. When shutting down the engine, fuel flows into the combustion chamber, which could result in a slight increase of rundown time or emission of smoke through the exhaust pipe, the air intake, or the turbine casing drain after the rotating assembly has stopped. This condition might be caused by the thermal stresses to which the injection wheel is subjected or a malfunctioning electric fuel cock. If there is smoke, that action requires inspecting for fuel flow. If there is no fuel flow, the engine might have injection wheel cracks, which would require removing the engine from service for repair. If there is fuel flow, the engine might have a malfunctioning electric fuel cock, which would require removing the electric fuel cock from service and replacing it with a serviceable part. That action also requires inspection of central labyrinths not previously inspected, or not replaced after the engine logged 1,500 operating hours, and, replacement if necessary. That action also requires the removal of injection wheels at a new lower life limit. These conditions, if not corrected, could result in injection wheel cracks, which could result in an in-flight engine shutdown.

Actions Since AD 2002-22-11 was Issued

Since AD 2002-22-11 was issued, The Direction Generale de L'Aviation Civile (DGAC), which is the airworthiness authority for France, notified the FAA that an unsafe condition might continue to exist on Turbomeca Artouste III B, B1, and D series turboshaft engines. The DGAC advises that operators have continued to report cracks on the rear face of the injection wheels, which can lead to fuel leakage into the turbine shaft tube during operation. Turbomeca has reviewed the latest in-service data that shows that in-flight engine shutdowns have continued to occur. As a result, this proposed AD includes the same requirements as the existing AD, but would reduce the compliance time for the initial inspection of the central labyrinth and adds a requirement for repetitive inspections of the central labyrinth.

Relevant Service Information

We have reviewed and approved the technical contents of Turbomeca Artouste III Service Bulletin (SB) No A218 72 0099, Update 1, dated June 6, 2001, that specifies procedures for smoke emission checks, and fuel flow inspections if smoke is detected. We have also reviewed and approved Turbomeca Artouste III Service Bulletin (SB) No. A218 72 00100, Update 2, dated January 23, 2004, that specifies procedures for inspection and replacement of central labyrinths. The DGAC classified these SB's as mandatory and issued AD F-2004-016, dated February 4, 2004, in order to assure the airworthiness of these Turbomeca Artouste III series engines in France.

Differences Between the Proposed AD and the Service Information

The manufacturer calls for a check for smoke emission through the exhaust pipe, air intake, or turbine casing drain during rundown and after every engine shutdown. This proposal will require the same check, except it will only be required after the last flight of the day. Also, the manufacturer calls for inspection of the central labyrinth using ratios based on cycles per hour starting with the published date of the SB. This proposal will require the same inspection ratios beginning at the effective date of the proposed AD.

Bilateral Agreement Information

This engine model is manufactured in France 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. Under this bilateral airworthiness agreement, the DGAC kept us informed of the situation described above. We have examined the findings of the DGAC, 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 and Requirements of the Proposed AD

Since we have identified an unsafe condition that is likely to exist or develop on other Turbomeca engines of the same type design that are used on helicopters registered in the United States, the proposed AD would require:

• Smoke emission checks after each last flight of the day.
• If there is smoke, then inspect for fuel flow.
• If there is no fuel flow, remove the engine from service for repair.
• If there is fuel flow, remove the electric fuel cock from service and replace with a serviceable part.
• Initial inspection of central labyrinths within 1,750 hours Time-Since-New or 50 hours from the effective date of this AD, whichever occurs later.
• Repetitive inspection of central labyrinths within 1,750 hours time-since-last inspection.

The proposed AD would require that you do these actions using the service information described previously.

Interim Action

These actions are interim actions and we may take further rulemaking actions in the future.

Costs of Compliance

There are about 1,062 Turbomeca Artouste III engines of the affected design in the worldwide fleet. We estimate that 59 engines installed on helicopters of U.S. registry would be affected by this proposed AD. We also estimate that it would take about 31 work hours per engine to perform the proposed actions, and that the average labor rate is $65 per work hour. Required parts would cost about $8,100 per engine. Based on these figures, we estimate the proposed AD would cost U.S. operators $596,785.

Special Flight Permits Paragraph Removed

Paragraph (e) of the current AD, AD 2002-22-11, contains a paragraph pertaining to special flight permits. Even though this final rule does not contain a similar paragraph, we have made no changes with regard to the use of special flight permits to operate the airplane to a repair facility to do the work required by this AD. In July 2002, we published a new 14 CFR part 39 that contains a general authority regarding special flight permits and airworthiness directives; see Docket No. FAA-2004-8460, Amendment 39-9474 (69 FR 47998, July 22, 2002). Thus, when we now supersede ADs we will not include a specific paragraph on special flight permits unless we want to limit the use of that general authority granted in section 39.23.

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

We prepared a summary of the costs to comply with this proposal and placed it in the AD Docket. You may get a copy of this summary at the address listed under ADDRESSES.

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 Amendment 39-12937 (67 FR 68022, November 8, 2002) and by adding a new airworthiness directive, to read as follows:

Turbomeca: Docket No. 99-NE-32-AD.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by August 22, 2005.

Applicability

(b) This AD applies to Turbomeca Artouste III B, B1, and D series turboshaft engines with injection wheels part numbers (P/Ns) 218.25.700.0, 218.25.704.0, 243.25.709.0, 243.25.713.0, 0.218.27.705.0, 0.218.27.709.0, and 0.218.27.713.0. These engines are installed on, but not limited to Eurocopter SA 315 LAMA and SA 316 Alouette III helicopters.

Compliance

(c) Compliance with this AD is required as indicated, unless already done. To prevent injection wheel cracks and excessive central labyrinth wear, which could result in an in-flight engine shutdowns, do the following:

Smoke Check

(d) Following every engine ground shutdown, do the following using Turbomeca Artouste III Service Bulletin (SB) No. 218 72 0099, dated September 14, 1998:

(1) After every flight, check for smoke emissions through the exhaust pipe, air intake, or turbine casing drain during rundown and after every engine shutdown. If a smoke emission has been noticed, check the fuel system before the next flight to identify the origin of the smoke emissions.

(2) If smoke is not detected, no action is required until the next engine ground shutdown.

(3) If smoke is detected, inspect for fuel flow in accordance with paragraph 2.B.(1) and 2.B.(2) of the referenced SB.

(i) If fuel flow is not detected, prior to further flight, remove the engine from service and replace with a serviceable engine.

(ii) If fuel flow is detected, remove the electric fuel cock from service and replace with a serviceable part in accordance with section 2.B.(4) and 2.B.(5) of the referenced SB.

(iii) Before entry into service, perform an engine ground run and check the fuel system again for smoke emissions through the exhaust pipe, air intake, or turbine casing drain during engine rundown and after shut-down; if smoke emissions still remain after replacement of the electric fuel cock, prior to further flight, remove the engine from service and replace with a serviceable engine.

(e) For the purpose of this AD, a serviceable engine is defined as an engine that does not exhibit smoke emissions.

Central Labyrinth Inspection

(f) Perform checks and inspections of the central labyrinth and, if necessary, replace the central labyrinth, using paragraph 2. of Turbomeca ASB No. A218 72 0100, Update 2, dated January 23, 2004, and the following Table 1:

Table 1.—Inspection Schedule

Initial inspection	Repetitive inspection
Prior to 1,750 hours Time-Since-New or 1,750 hours Time-Since-Last Inspection (TSLI), or 50 hours from the effective date of this AD, whichever occurs later	1,750 hours TSLI.

Alternative Methods of Compliance

(g) The Manager, Engine Certification Office, has the authority to approve alternative methods of compliance for this AD if requested using the procedures found in 14 CFR 39.19.

Related Information

(h) DGAC airworthiness directive F-2004-016, dated February 4, 2004, also addresses the subject of this AD.

Issued in Burlington, Massachusetts, on June 15, 2005.

Robert E. Guyotte,

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