[Federal Register Volume 75, Number 242 (Friday, December 17, 2010)]
[Proposed Rules]
[Pages 78937-78939]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-31782]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2009-1185; Directorate Identifier 2009-NE-24-AD]
RIN 2120-AA64


Airworthiness Directives; Honeywell International LTS101 Series 
Turboshaft Engines and LTP101 Series Turboprop Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Supplemental notice of proposed rulemaking (NPRM); reopening of 
comment period.

-----------------------------------------------------------------------

SUMMARY: This supplemental NPRM revises an earlier proposed 
airworthiness directive (AD), for Honeywell International LTS101-600A 
series and LTS101-700D-2 turboshaft engines, and LTP101-600A-1A and 
LTP101-700A-1A turboprop engines with power turbine blades, part number 
(P/N) 4-141-084-06, installed. That proposed AD would have required 
removing power turbine blades, P/N 4-141-084-06 from service, using a 
drawdown schedule specified in that proposed AD. That proposal was 
prompted by reports of fatigue cracks in the airfoil of the power 
turbine blade. This action revises the proposed rule by expanding and 
clarifying the applicability to include more engine models and power 
turbine blade P/Ns that could have the unsafe condition, and by 
clarifying the applicability by specifying power turbine rotor P/Ns 
instead of the blade P/Ns. The actions specified by this proposed AD 
are intended 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.

DATES: We must receive any comments on this proposed AD by February 15, 
2011.

ADDRESSES: Use one of the following addresses to comment on this 
proposed AD.
     Federal eRulemaking Portal: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility, U.S. Department of 
Transportation, 1200 New Jersey Avenue, SE., West Building Ground 
Floor, Room W12-140, Washington, DC 20590-0001.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
     Fax: (202) 493-2251.
    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 the service information identified in this proposed 
AD.

FOR FURTHER INFORMATION CONTACT: Robert Baitoo, Aerospace Engineer, Los 
Angeles Aircraft Certification Office, FAA, Transport Airplane 
Directorate, 3960 Paramount Blvd., Lakewood, CA 90712-4137; e-mail: 
[email protected]; telephone (562) 627-5245; fax (562) 627-5210.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send us any written relevant data, views, or 
arguments regarding this proposal. Send your comments to an address 
listed under ADDRESSES. Include ``Docket No. FAA-2009-1185; Directorate 
Identifier 2009-NE-24-AD'' in the subject line of your comments. We 
specifically invite comments on the overall regulatory, economic, 
environmental, and energy aspects of the proposed AD. We will consider 
all comments received by the closing date and may amend the proposed AD 
in light of those comments.
    We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact 
with FAA personnel concerning this proposed AD. Using the search 
function of the Web site, anyone can find and read the comments in any 
of our dockets, including, if provided, the name of the individual who 
sent the comment (or signed the comment on behalf of an association, 
business, labor union, etc.). You may review the DOT's complete Privacy 
Act Statement in the Federal Register published on April 11, 2000 (65 
FR 19477-78).

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Operations office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains this proposed AD, the regulatory 
evaluation, any comments received, and other information. The street 
address for the Docket Operations office (telephone (800) 647-5527) is 
the same as the Mail address provided in the ADDRESSES section. 
Comments will be available in the AD docket shortly after receipt.

[[Page 78938]]

Discussion

    The FAA proposed to amend part 39 of the Federal Aviation 
Regulations (14 CFR part 39) to add an AD, applicable to Honeywell 
International LTS101-600A series and LTS101-700D-2 turboshaft engines, 
and LTP101-600A-1A and LTP101-700A-1A turboprop engines. We published 
the proposed AD in the Federal Register on December 21, 2009 (74 FR 
67829). That action proposed to require removing power turbine blades, 
P/N 4-141-084-06, from service using a specific drawdown schedule. That 
NPRM was prompted by reports of fatigue cracks in the airfoil of the 
power turbine blade. That condition, if not corrected, could result in 
fracture of the power turbine blade airfoil, which could result in 
sudden loss of engine power.
    Since we issued that NPRM, Honeywell International Inc. informed us 
that power turbine blades, P/N 4-141-084-03, could also have the unsafe 
condition. Those blades are used in power turbine rotors P/Ns 4-141-
290-02 and 4-141-290-16. Based on the information we received from 
Honeywell International Inc., we also determined that specifying the 
applicability by power turbine rotors P/N is clearer than by specifying 
the blade P/N.

Comments

    We provided the public the opportunity to participate in the 
development of that proposed AD. We have considered the comments 
received on the original NPRM.

Proposed AD Should Apply to Engines on Multi-Engine Helicopters

    One commenter, the National Transportation Safety Board (NTSB) asks 
us to consider adding to the applicability of the proposed AD, engines 
that also use the affected P/N turbine rotor blade, and are installed 
on multi-engine helicopters. The NTSB states that loss of power in one 
of the two engines is a safety issue.
    We agree with the NTSB that the fracture of a power turbine airfoil 
of an LTS101 series turboshaft engine installed on a twin-engine 
helicopter is a safety issue. We added Honeywell International Inc. 
LTS101-650B-1, LTS101-650C-3, LTS101-650C-3A, LTS101-750B-1, LTS101-
750B-2, LTS101-750C-1, and LTS101-850B-2 turboshaft engines that are 
installed on twin-engine helicopters to the applicability of the 
proposed AD. We also added to the applicability, paragraph (g), and 
Table 1 of the proposed AD, Honeywell International Inc. LTP101-600A-1A 
and LTP101-700A-1A turboprop engines that use the same blades.
    The NTSB also requested that we reduce the drawdown schedule for 
the affected blades to remove the at risk power turbine rotor blades 
sooner.
    We don't agree. Our risk assessment for the unsafe condition 
doesn't justify accelerating the drawdown schedules.

Editorial Changes to Table 1 and Table 1 of the Proposed AD

    We changed Table 1 and Table 2 in the proposed AD to eliminate 
arbitrary step changes.
    Since these changes expand the scope of the originally proposed 
rule, we determined that reopening the comment period is appropriate.

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 Honeywell International Inc. 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 
engines of the same type design, the proposed AD would require removing 
from service, power turbine rotors, P/Ns 4-141-290-01, -02, -03, -05, -
06, -11, -12, -13, -14, or -16, using the compliance drawdown schedule 
specified in Table 1, and Table 2 of this AD.

Costs of Compliance

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

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 AD:
    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 regulatory evaluation of the estimated costs to 
comply with this proposed AD. 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, 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:

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.


Sec.  39.13  [Amended]

    2. The FAA amends Sec.  39.13 by adding the following new 
airworthiness directive:

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

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this airworthiness directive (AD) action by February 15, 
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 
engines with 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.

[[Page 78939]]

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     Then remove the power turbine
   effective date of this AD is * * *      rotor from the engine * * *
------------------------------------------------------------------------
(1) Fewer than 5,000 cycles-since-new    Between 5,000 and 5,500 CSN.
 (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     Then remove the power turbine
   effective date of this AD is * * *      rotor from 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; e-mail: 
[email protected]; telephone (562) 627-5245; fax (562) 627-5210, 
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.

    Issued in Burlington, Massachusetts, on December 13, 2010.
Thomas A. Boudreau,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 2010-31782 Filed 12-16-10; 8:45 am]
BILLING CODE 4910-13-P