AD 2011-08-06

We are adopting a new airworthiness directive (AD) for the products listed above. This AD requires removing certain power turbine rotors from service using a specific drawdown schedule. This AD was prompted by reports of fatigue cracks in the airfoil of the power turbine blades. We are issuing this AD to prevent fracture of the power turbine blade airfoil, which could result in sudden loss of engine power and prevent continued safe flight or safe landing.

Final rule.

Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0 1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

Sec. 39.13 [Amended]

0 2. The FAA amends Sec. 39.13 by adding the following new airworthiness directive (AD):

2011-08-06 Honeywell International Inc. (Formerly AlliedSignal, Textron Lycoming): Amendment 39-16656; Docket No. FAA-2009-1185; Directorate Identifier 2009-NE-24-AD.

Effective Date

(a) This AD is effective May 17, 2011.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Honeywell International LTS101-600A-2, - 3, -3A, LTS101-700D-2, LTS101-650B-1, LTS101-650C-3, LTS101-650C-3A, LTS101-750B-1, LTS101-750B-2, LTS101-750C-1, and LTS101-850B-2 turboshaft engines; and LTP101-600A-1A and LTP101-700A-1A turboprop engineswith power turbine rotor, part number (P/N) 4-141-290-01, - 02, -03, -05, -06, -11, -12, -13, -14, or -16, installed. These engines are installed on, but not limited to, Eurocopter AS350 and BK117 series and Bell 222 series helicopters; and Page Thrush, Air Tractor AT-302, and Pacific Aero 08-600, Piaggio P166 DL3, and Riley International R421 airplanes.

Unsafe Condition

(d) This AD results from reports of fatigue cracks in the airfoil of the power turbine blade. We are issuing this AD to prevent fracture of the power turbine blade airfoil, which could result in sudden loss of engine power and prevent continued safe flight or safe landing.

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.
(f) For engines with power turbine rotors, P/Ns 4-141-290-11, - 12, -13, and -14, marked with ``ORI T41881,'' on the aft hub in the vicinity of the P/N, no further action is required.

Removing Power Turbine Rotors From LTS101-600A-2, -3, -3A, and LTS101- 700D-2 Turboshaft Engines and LTP101-600A-1A and LTP101-700A-1A Turboprop Engines

(g) For LTS101-600A-2, -3, -3A, and LTS101-700D-2 turboshaft engines and LTP101-600A-1A and LTP101-700A-1A turboprop engines, remove power turbine rotors, P/Ns 4-141-290-01, -02, -03, -05, -06, -11, -12, -13, -14, or -16, using the cycles specified in Table 1 of this AD:

Table 1--Drawdown Cycles for LTS101-600A-2, -3, -3A, and LTS101-700D-2
Turboshaft Engines and LTP101-600A-1A and LTP101-700A-1A Turboprop
Engines ------------------------------------------------------------------------
If power turbine rotor time on the effective date of this Then remove the power turbine rotor from
AD is . . . the engine . . . ------------------------------------------------------------------------ (1) Fewer than 5,000 cycles- Between 5,000 and 5,500 CSN.
since-new (CSN). (2) 5,000 to 7,899 CSN....... Within 500 cycles-in-service (CIS) after
the effective date of this AD or before
exceeding 8,000 CSN, whichever occurs
first. (3) 7,900 to 9,999 CSN....... Within 100 CIS after the effective date
of this AD or before exceeding 10,050
CSN, whichever occurs first. (4) 10,000 or more CSN....... Within 50 CIS after the effective date of
this AD. ------------------------------------------------------------------------

Removing Power Turbine Rotors From LTS101-650B-1, -650C-3,--650C-3A, - 750B-1, -2, -750C-1, and -850B-2 Engines

(h) Remove power turbine rotors, P/Ns 4-141-290-01, -02 -03, - 05, -06, -11, -12, -13, -14, or -16, using the cycles specified in Table 2 of this AD:

Table 2--Drawdown Cycles for LTS101-650B-1, -650C-3,-650C-3A, -750B-1, -
2, -750C-1, and -850B-2 Engines ------------------------------------------------------------------------
If power turbine rotor time on the effective date of this Thenremove the power turbine rotor from
AD is . . . the engine . . . ------------------------------------------------------------------------ (1) Fewer than 5,500 CSN..... Between 5,000 and 7,200 CSN. (2) 5,500 to 7,999 CSN....... Within 1,700 CIS after the effective date
of this AD or before exceeding 8,950
CSN, whichever occurs first. (3) 8,000 to 9,999 CSN....... Within 950 CIS after the effective date
of this AD or before exceeding 10,400
CSN, whichever occurs first. (4) 10,000 or more CSN....... Within 400 CIS after the effective date
of this AD. ------------------------------------------------------------------------

Alternative Methods of Compliance

(i) The Manager, Los Angles Aircraft 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

(j) Contact Robert Baitoo, Aerospace Engineer, Los Angeles Aircraft Certification Office, FAA, Transport Airplane Directorate, 3960 Paramount Blvd., Lakewood, CA 90712-4137; phone: 562-627-5245; fax: 562-627-5210; e-mail: robert.baitoo@faa.gov, for more information about this AD.
(k) Honeywell International Inc. Service Bulletins LT 101-71-00- 0252 and LTS101-71-00-0253, pertain to the subject of this AD. Contact Honeywell International Inc., P.O. Box 52181, Phoenix, AZ 85072-2181; telephone (800) 601-3099 (U.S.A.) or (602) 365-3099 (International); or go to: https://portal.honeywell.com/wps/portal/aero, for a copy of this service information.

Discussion

We issued a supplemental notice of proposed rulemaking (SNPRM) to amend 14 CFR part 39 to include an AD that would apply to the specified products. That SNPRM published in the Federal Register on December 17, 2010 (75 FR 78937). The original notice of proposed rulemaking (74 FR 67829, December 21, 2009) proposed to require removing power turbine blades, part number (P/N) 4-141-084-06 from service, using a drawdown schedule. The SNPRM proposed to require expanding and clarifying the applicability to include more engine models and power turbine blade P/ Ns that could have the unsafe condition, and clarifying the applicability by specifying power turbine rotor P/Ns instead of the blade P/Ns.

Comments

We gave the public the opportunity to participate in developing this AD. We received no comments on the SNPRM.

Conclusion

We reviewed the relevant data and determined that air safety and the public interest require adopting the AD as proposed.

Costs of Compliance

We estimate that this AD will affect 240 engines installed on aircraft of U.S. registry. We also estimate that it will take about 30 work-hours per engine to perform the actions, and that the average labor rate is $85 per work-hour. If all removed power turbine rotors get replaced, required parts will cost about $70,000 per engine. Based on these figures, we estimate the total cost of the AD to U.S. operators to be $17,412,000.

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

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),
(3) Will not affect intrastate aviation in Alaska, and(4) 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.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.

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