06-522. Airworthiness Directives; Turbomeca Arriel 1B, 1D, 1D1, and 1S1 Turboshaft Engines

AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT).

ACTION:

Final rule; request for comments.

SUMMARY:

The FAA is adopting a new airworthiness directive (AD) for certain Turbomeca Arriel 1B, 1D, 1D1, and 1S1 turboshaft engines. This AD requires initial and repetitive position checks of the gas generator 2nd stage turbine blades on all Turbomeca Arriel 1B, 1D, 1D1, and 1S1 turboshaft engines, and initial and repetitive replacements of 2nd stage turbines on 1B, 1D, and 1D1 engines only. This AD results from reports of the release of gas generator 2nd stage turbine blades while in service, with full containment of debris. We are issuing this AD to prevent inflight engine shutdown and subsequent forced autorotation landing or accident.

DATES:

This AD becomes effective February 28, 2006. The Director of the Federal Register approved the incorporation by reference of certain publications listed in the regulations as of February 28, 2006.

We must receive any comments on this AD by March 27, 2006.

ADDRESSES:

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

• DOT Docket Web site: Go to http://dms.dot.gov and follow the instructions for sending your comments electronically.
• Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
• Mail: Docket Management Facility; U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, Washington, DC 20590-0001.
• Fax: [phone].
• Hand Delivery: Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

Contact Turbomeca, 40220 Tarnos, France; telephone [phone], fax [phone], for the service information identified in this 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:

The FAA proposed to amend 14 CFR part 39 with a proposed airworthiness directive (AD). The proposed AD applies to Turbomeca Arriel 1B engines fitted with 2nd stage turbine modification TU 148, and Arriel 1D, 1D1, and 1S1 engines. We published the proposed AD in the Federal Register on June 28, 2005 (70 FR 37063). That action proposed to require initial and repetitive position checks of the 2nd stage turbine blades on Turbomeca Arriel 1B, 1D, 1D1, and 1S1 turboshaft engines, and replacement of 2nd stage turbines on 1B and 1D1 engines only.

Examining the AD Docket

You may examine the docket that contains the AD, any comments received, and any final disposition in person at the Docket Management Facility Docket Office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Office (telephone [phone]) is located on the plaza level of the Department of Transportation Nassif Building at the street address stated in ADDRESSES. Comments will be available in the AD docket shortly after the DMS receives them.

Comments

We provided the public the opportunity to participate in the development of this AD. We have considered the comments received.

Request To Change the Compliance Time

One commenter, Turbomeca, requests we change the compliance time for replacing 2nd stage turbines to, immediately upon receipt of a replacement 2nd stage turbine from Turbomeca, and at least by August 31, 2006. The commenter states that without this requirement, operators will incur unacceptable and unnecessary risk for engines operating past the hourly life limit. The commenter further states that an unacceptable number of engines will require replacement 2nd stage turbines at the compliance end-date, causing grounding of aircraft because of a lack of replacement parts. We partially agree. There is a need to replace the 2nd stage turbines as they reach the hourly life limit, and to strive to not allow them to stay installed until the compliance end-date. However, replacing them immediately upon receipt could unnecessarily create compliance problems for operators. An example would be if a helicopter is at a remote site the day an operator receives a replacement 2nd stage turbine. We changed the compliance to read “After accumulating 1,500 hours TSN or TSO for Arriel 1D and 1D1 engines, and 2,200 hours TSN or TSO for Arriel 1B engines, initially replace the 2nd stage turbine with a new or overhauled 2nd stage turbine as soon as practicable, but no later than August 31, 2006.” This change prevents compliance problems associated with the commenter's phrase “immediately upon receipt” yet still requires prompt replacement of 2nd stage turbines after one becomes available.

NPRM Not Clear About Ongoing Requirement

The same commenter states that the NPRM is not clear that replacing the 2nd stage turbines is an ongoing requirement. We agree. We changed the compliance in this AD to address initial and repetitive replacements of 2nd stage turbines.

Inspection and Replacement Requirements Changed for Arriel 1D Turboshaft Engines

The same commenter states that the requirements for inspecting and replacing Arriel 1D turboshaft engines have changed since we issued the NPRM. Those requirements are now the same as for Arriel 1D1 turboshaft engines. We agree. We changed the compliance in this AD to shorten the repetitive inspection interval and add the requirement to replace the 2nd stage turbine. However, since many of the Arriel 1D turboshaft engines may be at or near the compliance time for replacing the 2nd stage turbine, we have found that notice and opportunity for further comment before issuing this AD, are impracticable. We are issuing this AD as a final rule; request for comments, allowing operators to comment after the AD publishes.

Conclusion

We have carefully reviewed the available data, including the comments received, and determined that air safety and the public interest require adopting the AD with the changes described previously. We have determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.

Interim Action

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

Costs of Compliance

There are about 2,557 Turbomeca Arriel 1B, 1D, 1D1 and 1S1 turboshaft engines of the affected design in the worldwide fleet. We estimate that this AD will affect 721 engines installed on helicopters of U.S. registry. We estimate that it will take about 2 work hours per engine to inspect all 721 engines and 40 hours per engine to replace about 571 2nd stage turbines on 1B and 1D1 engines, and that the average labor rate is $65 per work hour. Required parts will cost about $3,200 per engine. Based on these figures, we estimate the total cost of the AD to U.S. operators to be $3,405,530.

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 AD will not have federalism implications under Executive Order 13132. This AD will 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 this AD:

(1) Is not a “significant regulatory action” under Executive Order 12866;

(2) Is not a “significant rule” under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and

(3) 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.

We prepared a summary of the costs to comply with this AD 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
• Incorporation by reference
• Safety

Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the Federal Aviation Administration amends 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 adding the following new airworthiness directive:

2006-02-08 Turbomeca: Amendment 39-14460; Docket No. FAA-2005-21242; Directorate Identifier. 2005-NE-09-AD.

Effective Date

(a) This airworthiness directive (AD) becomes effective February 28, 2006.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Turbomeca Arriel 1B engines fitted with 2nd stage turbine modification TU 148, and Arriel 1D, 1D1, and 1S1 engines. Arriel 1B engines are installed on, but not limited to, Eurocopter France AS-350B and AS-350A “Ecureuil” helicopters; 1D engines are installed on, but not limited to, Eurocopter France AS-350B1 “Ecureuil” helicopters; 1D1 engines are installed on, but not limited to, Eurocopter France AS-350B2 “Ecureuil” helicopters; and Arriel 1S1 engines are installed on, but not limited to, Sikorsky Aircraft S-76A and S-76C helicopters.

Unsafe Condition

(d) This AD results from reports of the release of gas generator 2nd stage turbine blades while in service, with full containment of debris. We are issuing this AD to prevent inflight engine shutdown and subsequent forced autorotation landing or accident.

Compliance

(e) You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done.

Initial Relative Position Check of 2nd Stage Turbine Blades

(f) Do an initial relative position check of the 2nd stage turbine blades using the Turbomeca mandatory alert service bulletins (ASBs) specified in the following Table 1 before reaching any of the intervals specified in Table 1 or within 50 hours time-in-service after the effective date of this AD, whichever occurs later.

Table 1.—Initial and Repetitive Relative Position Check Intervals of 2nd Stage Turbine Blade

Turbomeca engine model	Initial relative position check interval	Repetitive interval	Mandatory alert service bulletin
Arriel 1B (modified per TU 148)	Within 1,200 hours time-since-new (TSN) or time-since-overhaul (TSO) or 3,500 cycles-since-new (CSN) or cycles-since-overhaul (CSO), whichever occurs earlier	Within 200 hours time-in-service-since-last-relative-position-check (TSLRPC)	A292 72 0807, dated March 24, 2004.
Arriel 1D1 and Arriel 1D	Within 1,200 hours TSN or TSO or 3,500 hours CSN or CSO, whichever occurs earlier	Within 150 hours TSLRPC	A292 72 0809, Update No. 1, dated October 4, 2005.
Arriel 1S1	Within 1,200 hours TSN or TSO or 3,500 hours CSN or CSO, whichever occurs earlier	Within 150 hours TSLRPC	A292 72 0810, dated March 24, 2004.

Repetitive Relative Position Check of 2nd Stage Turbine Blades

(g) Recheck the relative position of 2nd stage turbine blades at the TSLRPC intervals specified in Table 1 of this AD, using the mandatory ASBs indicated.

Credit for Previous Relative Position Checks

(h) Relative position checks of 2nd stage turbine blades done using Turbomeca Service Bulletin A292 72 0263, Update 1, 2, 3, or 4, may be used to show compliance with the initial requirements of paragraph (f) of this AD.

Initial Replacement of 2nd Stage Turbines on Arriel 1B, 1D, and 1D1 Engines

(i) After accumulating 1,500 hours TSN or TSO for Arriel 1D and 1D1 engines, and 2,200 hours TSN or TSO for Arriel 1B engines, initially replace the 2nd stage turbine with a new or overhauled 2nd stage turbine as soon as practicable, but no later than August 31, 2006.

Repetitive Replacements of 2nd Stage Turbines on Arriel 1B, 1D, and 1D1 Engines

(j) Thereafter, replace the 2nd stage turbine with a new or overhauled 2nd stage turbine within every 1,500 hours TSN or TSO for Arriel 1D and 1D1 engines, and within every 2,200 hours TSN or TSO for Arriel 1B engines.

Criteria for Overhauled 2nd Stage Turbines

(k) Do the following to overhauled 2nd stage turbines, referenced in paragraphs (i) and (j) of this AD:

(1) You must install new blades in the 2nd stage turbines of overhauled Arriel 1D and 1D1 engines.

(2) You may install either overhauled or new blades in the 2nd stage turbines of overhauled Arriel 1B engines.

Relative Position Check Continuing Compliance Requirements

(l) All 2nd stage turbines, including those that are new or overhauled, must continue to comply with relative position check requirements of paragraphs (f) and (j) of this AD.

Alternative Methods of Compliance

(m) 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

(n) DGAC airworthiness directive F-2004-047 R1, dated October 26, 2005, also addresses the subject of this AD.

Material Incorporated by Reference

(o) You must use the service information specified in Table 2 of this AD to perform the actions required by this AD. The Director of the Federal Register approved the incorporation by reference of the documents listed in Table 2 of this AD in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Contact Turbomeca, 40220 Tarnos, France; telephone [phone], fax [phone], for a copy of this service information. You may review copies at the Docket Management Facility; U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, Washington, DC 20590-0001, on the Internet at http://dms.dot.gov, or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/​federal-register/​cfr/​ibr-locations.html.

Table 2.—Incorporation by Reference

Turbomeca mandatory alert service bulletin No.	Page	Update No.	Date
A292 72 0807	ALL	Original	March 24, 2004.
Total Pages: 17
A292 72 0809	ALL	1	October 4, 2005.
Total Pages: 18
A292 72 0810	ALL	Original	March 24, 2004.
Total Pages: 14

Issued in Burlington, Massachusetts, on January 12, 2006.

Peter A. White,

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