
[Federal Register Volume 78, Number 102 (Tuesday, May 28, 2013)]
[Proposed Rules]
[Pages 31863-31867]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-12523]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2013-0454; Directorate Identifier 2009-SW-081-AD]
RIN 2120-AA64


Airworthiness Directives; Sikorsky Aircraft Corporation-
Manufactured (Sikorsky) Model Helicopters (type certificate currently 
held by Erickson Air-Crane Incorporated)

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to supersede an existing airworthiness directive 
(AD) for Sikorsky Aircraft Corporation-manufactured Model S-64E 
helicopters (type certificate currently held by Erickson Air-Crane 
Incorporated (Erickson)). That AD currently requires inspecting and 
reworking the main gearbox (MGB) assembly second stage lower planetary 
plate (plate). This action would establish or reduce the life limits 
for certain flight-critical components, remove from service various 
parts, require repetitive inspections and other corrective actions, and 
require replacing any cracked part discovered during an inspection. 
This proposal is prompted by further analysis performed by the current 
type certificate holder and the service history of certain parts. The 
actions specified in the proposed AD are intended to prevent a crack in 
a flight critical component, failure of a critical part, and subsequent 
loss of control of the helicopter.

DATES: We must receive comments on this proposed AD by July 29, 2013.

ADDRESSES: You may send comments by any of the following methods:
     Federal eRulemaking Docket: Go to http://www.regulations.gov. Follow the online instructions for sending your 
comments electronically.
     Fax: 202-493-2251.
     Mail: Send comments to the U.S. Department of 
Transportation, Docket Operations, M-30, West Building Ground Floor, 
Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590-0001.
     Hand Delivery: Deliver to the ``Mail'' address between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.

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 economic 
evaluation, any comments received and other information. The street 
address for the Docket Operations Office (telephone 800-647-5527) is in 
the ADDRESSES section. Comments will be available in the AD docket 
shortly after receipt.
    For service information identified in this proposed AD, contact 
Erickson Air-Crane Incorporated, ATTN: Chris Erickson/Compliance 
Officer, 3100 Willow Springs Rd, PO Box 3247, Central Point, OR 97502, 
telephone

[[Page 31864]]

(541) 664-5544, fax (541) 664-2312, email address 
cerickson@ericksonaircrane.com. You may review a copy of the service 
information at the FAA, Office of the Regional Counsel, Southwest 
Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137.

FOR FURTHER INFORMATION CONTACT: Michael Kohner, Aerospace Engineer, 
Rotorcraft Certification Office, Rotorcraft Directorate, FAA, 2601 
Meacham Blvd., Fort Worth, TX 76137; telephone (817) 222-5170; email 7-avs-asw-170@faa.gov.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite you to participate in this rulemaking by submitting 
written comments, data, or views. We also invite comments relating to 
the economic, environmental, energy, or federalism impacts that might 
result from adopting the proposals in this document. The most helpful 
comments reference a specific portion of the proposal, explain the 
reason for any recommended change, and include supporting data. To 
ensure the docket does not contain duplicate comments, commenters 
should send only one copy of written comments, or if comments are filed 
electronically, commenters should submit only one time.
    We will file in the docket all comments that we receive, as well as 
a report summarizing each substantive public contact with FAA personnel 
concerning this proposed rulemaking. Before acting on this proposal, we 
will consider all comments we receive on or before the closing date for 
comments. We will consider comments filed after the comment period has 
closed if it is possible to do so without incurring expense or delay. 
We may change this proposal in light of the comments we receive.

Discussion

    On September 5, 1997, we issued AD 97-19-10, Amendment 39-10130 (62 
FR 47933, September 12, 1997), to require, at 1,300 hours time-in-
service (TIS), a fluorescent-magnetic particle inspection of the plate, 
part number (P/N) 6435-20229-102, for a crack, replacing the plate if a 
crack is found, and reworking the plate if there is no crack. That 
action also requires, at 1,500 hours TIS, and thereafter at intervals 
not to exceed 70 hours TIS, for a reworked plate, P/N 6435-20229-102, 
and for plate, P/N 6435-20229-104, inspecting for a crack and replacing 
the main gearbox assembly if a crack is found. Finally, AD 97-19-10 
requires retiring these part-numbered plates upon reaching 2,600 hours 
TIS. That action was prompted by reports that cracks were discovered in 
four plates, three of which had been reworked in accordance with 
previously superseded AD 77-20-01, Amendment 39-3045 (42 FR 51565, 
September 29, 1977) and Amendment 39-3064 (42 FR 56600, October 27, 
1977). The requirements of AD 97-19-10 are intended to detect a crack 
in the plate to prevent failure of the plate, failure of the main 
gearbox, and subsequent loss of control of the helicopter.

Actions Since Existing AD Was Issued

    Since issuing AD 97-19-10, Amendment 39-10130 (62 FR 47933, 
September 12, 1997), Erickson has performed a configuration review and 
additional analyses of the safe life for various parts and released 
Erickson Service Bulletin (SB) No. 64B General-1, Revision 19, dated 
September 15, 2010 (SB 64B General-1). SB 64B General-1 specifies the 
retirement life for certain parts and assemblies as well as noting 
other maintenance actions. This and the previous revisions of SB 64B 
General-1 contain reduced or new life limits for certain parts, parts 
which should be removed from service, other maintenance actions, and 
various other provisions for certain parts. We have also reviewed 
Erickson SB No. 64B10-3, Revision D, dated October 15, 2007, which 
provides ultrasonic inspection procedures for the Main Rotor (M/R) hub 
horizontal hinge pins. Based on our review of this list of parts and 
assemblies, and an analysis of the service difficulties, we have 
determined that we need to propose to revise the life limit of certain 
critical parts, remove certain parts from service, and require 
additional inspections and other maintenance actions of certain parts. 
Failure to establish or revise a life limit or remove a part from 
service when there is repeated service difficulties with the part could 
result in failure of that part and subsequent loss of control of the 
helicopter.

FAA's Determination

    We are proposing this AD because we evaluated all the relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other helicopters of the same type 
design.

Proposed AD Requirements

    The proposed AD would supersede AD 97-19-10 (62 FR 47933, September 
12, 1997) to establish or revise the life limit for various parts, to 
remove various parts from service, to require various inspections and 
other maintenance actions, and to revise the component history card or 
equivalent record and the airworthiness limitations section of the 
maintenance manual accordingly. Specifically, we propose, before 
further flight, to establish or to revise the retirement life for each 
of the following parts, and to remove from service those parts that 
have reached or exceeded the newly established or reduced life limit:
     M/R parts
    [cir] Rod and bushing assembly, M/R, P/N 6410-21090-012, -013 or -
014;
    [cir] Lower plate, M/R hub, P/N 6410-23009-102;
    [cir] Upper plate, M/R hub, P/N 6410-23011-102;
    [cir] Swashplate, rotating, M/R, P/N 6410-24002-101;
    [cir] Piston rod, P/N 6410-26005-104;
    [cir] Cylinder, damper assembly, P/N 6410-26215-101;
    [cir] M/R blade, P/N 6415-20201-045 or -047;
    [cir] M/R blade, P/N 6415-20201-048, -049, -050, or -051;
    [cir] M/R shaft assembly (includes shaft, P/N 6435-20078-104), P/N 
6435-20078-014 or -015;
    [cir] M/R shaft assembly (includes shaft, P/N 6435-20078-105), P/N 
6435-20078-016;
    [cir] Hub, M/R, P/N S1510-23001-005;
    [cir] Spindle assembly, M/R, P/N S1510-23027-5;
    [cir] Horn assembly, M/R, P/N S1510-23350-4, -6, or -8;
    [cir] Sleeve, M/R, P/N S1510-23351-2;
    [cir] Sleeve lockwasher, M/R, S1510-23458-0;
    [cir] Cuff, M/R blade, P/N S1515-20320-0, -001 or -002;
    [cir] Piston assembly, M/R tandem servo, P/N S1565-20443-0 or 
S1565-20443-301;
    [cir] Fork assembly, M/R tandem servo, P/N S1565-20449 or P/N 
S1565-20449-301;
     Tail Rotor (T/R) parts
    [cir] T/R blade, P/N 65160-00001-042, -045, or -048;
    [cir] T/R blade, P/N 65161-00001-042;
    [cir] Bearing, T/R drive shaft, P/N SB1111-004 or -601;
     Main Gearbox parts
    [cir] Second stage planetary plate assembly, main gearbox assembly, 
P/N 6435-20231-012, -014, -015 or -016;
    [cir] Oil cooler and support assembly, P/N 6435-60050-044; and
     Other parts
    [cir] Truss assembly, stabilizer, P/N 6420-66250-041.
    In addition to establishing and revising the life limit for certain 
parts, we also propose to require, before further flight, removing from 
service the

[[Page 31865]]

following flight-critical parts due to previous service difficulties:
     Rod and bushing assembly, M/R, P/N 6410-21090-011;
     M/R blade, P/N 6415-20001-013, -014, or -015;
     Pylon stabilizer, P/N 6420-66201-010, -014, or -015;
     M/R shaft assembly, P/N 6435-20078-013;
     Oil cooler and support assembly, P/N 6435-60050-043;
     Pitch change link, rotary rudder, P/N 65113-07100-046; and
     Spindle, M/R blade, P/N S1510-23070-3.

Any part that is required to be removed from service is not eligible 
for installation on any helicopter.
    This proposed AD also would also require the following inspections 
and other corrective actions:
     Within 20 hours TIS, and thereafter at intervals not to 
exceed 20 hours TIS, inspecting each M/R servo and control arm 
assembly, P/N S1565-20421-10, -11, -041, or -043, for any oil leaking 
from the M/R tandem servo housing assembly (servo housing), P/N S1565-
20252-2. If there is any oil leaking from the servo housing, before 
further flight, replacing the M/R servo and control arm assembly.
     Within 20 hours TIS or before reaching a total of 1,120 
hours TIS, whichever occurs later, and thereafter at intervals not to 
exceed 200 hours TIS or 12 months, whichever occurs first, performing 
an ultrasonic inspection (UT) of each M/R hub horizontal hinge pin, P/N 
S1510-23099-1 or P/N S1510-23099-001, for a crack.
     Performing a fluorescent-magnetic particle inspection 
(MPI) for a crack:
    [cir] In each second stage planetary plate assembly, P/N 6435-
20231-016, within 150 hours TIS, or before reaching 1,450 hours TIS, 
whichever occurs later;
    [cir] In each M/R shaft, P/N 6435-20078-104, within 150 hours TIS 
or before reaching 1,450 hours TIS, whichever occurs later, and 
thereafter at intervals not to exceed 650 hours TIS;
    [cir] In each M/R shaft, P/N 6435-20078-105, within 150 hours TIS 
or before reaching 1,450 hours TIS, whichever occurs later, and 
thereafter at intervals not to exceed 1,450 hours TIS; and
    [cir] In each M/R shaft assembly, P/N 6435-20078-014, -015, or -
016, at each overhaul of the main gearbox assembly, P/N 6435-20400-053, 
-054, -058, -060, -062, -063, -064, -065, or -066.
     Within 150 hours TIS or before reaching 3,375 hours TIS, 
whichever occurs later, and thereafter at intervals not to exceed 3,375 
hours TIS, performing a fluorescent-penetrant inspection (FPI) of each 
housing lug on each M/R tandem servo housing assembly, P/N S1565-20252-
2.
     If a there is a crack, before further flight, replacing 
the cracked part.
     At each overhaul of the damper assembly, P/N 6410-26200-
042, replacing certain parts with parts that have zero (0) hours TIS.

Differences Between the Proposed AD and the Service Information

    This proposed AD contains only those parts for the Model S-64E 
helicopters whose life limit has either been reduced or added for an 
existing P/N, whereas SB 64B General-1 also contains parts whose life 
limits have been extended. As a result, this proposed AD does not 
include all of the parts or P/Ns that are listed in SB 64B General-1.

Costs of Compliance

    We estimate that this proposed AD would affect 13 helicopters of 
U.S. registry, and the proposed actions would take the following number 
of estimated work hours to accomplish:
     26 work hours (2 work hours per helicopter) for the fleet 
to review the helicopter records or to remove a part to determine if an 
affected part is installed;
     845 work hours (65 work hours per helicopter) for the 
fleet to replace the parts or assemblies on or before reaching the 
retirement lives stated in Table 1 of the proposed AD, assuming an 
annual usage of 600 hours TIS;
     287 work hours per helicopter to replace all the parts or 
assemblies listed in Table 2 of the proposed AD;
     130 work hours (10 work hours per helicopter) for the 
fleet to inspect the M/R servo housing assemblies for an oil leak, 
assuming each inspection would take approximately 0.25 work hour per 
helicopter and would be accomplished 40 times annually;
     Approximately 293 work hours (22.5 work hours per 
helicopter) for the fleet to UT inspect each M/R hub horizontal hinge 
pin, assuming that each inspection would take 7.5 work hours per 
helicopter and would be accomplished 3 times annually;
     288 work hours (48 work hours per helicopter) to perform 
an MPI of each main gearbox second stage lower planetary plate and 
second stage planetary plate assembly assuming 6 helicopters would be 
inspected annually;
     192 work hours (32 work hours per helicopter) to perform 
an MPI of each M/R shaft and M/R shaft assembly, assuming 6 helicopters 
would be inspected annually, and
     96 work hours (32 work hours per helicopter) to perform an 
FPI of each M/R tandem servo housing assembly, assuming 3 helicopters 
would be inspected annually.
    Therefore, we estimate that it would take approximately 2,157 work 
hours to accomplish the proposed actions at a cost of $183,345, using 
an average labor rate $85 per work hour. Replacement parts would cost 
approximately:
     $5,363,449 ($412,573 per helicopter) to replace the parts 
or assemblies on the entire fleet on or before reaching the proposed 
retirement lives, assuming parts for 13 helicopters would require 
replacement; and
     $2,594,400 per helicopter to replace the parts or 
assemblies that are listed in Table 2 of the proposed AD.
    Using these assumptions, the estimated total cost for the required 
parts would be approximately $7,957,849. Based on these estimated 
amounts using these assumptions, we estimate the total cost impact of 
the proposed AD on the U.S. operators would be $8,141,194.

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 helicopters identified in this 
rulemaking action.

Regulatory Findings

    We 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, I certify this proposed regulation:
    1. Is not a ``significant regulatory action'' under Executive Order 
12866;

[[Page 31866]]

    2. Is not a ``significant rule'' under the DOT Regulatory Policies 
and Procedures (44 FR 11034, February 26, 1979);
    3. Will not affect intrastate aviation in Alaska to the extent that 
it justifies making a regulatory distinction; 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.
    We prepared an economic evaluation of the estimated costs to comply 
with this proposed AD and placed it in the AD docket.

List of Subjects in 14 CFR Part 39

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

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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 removing Amendment 39-10130 (62 FR 
47933, September 12, 1997), and adding the following new AD:

Sikorsky Aircraft Corporation-Manufactured (Sikorsky) Model 
Helicopters (Type Certificate Currently Held By Erickson Air-Crane 
Incorporated): Docket No. FAA-2013-0454; Directorate Identifier 
2009-SW-81-AD.

(a) Applicability

    This AD applies to Sikorsky Model CH-54A helicopters, now under 
the Erickson Air-Crane Incorporated (Erickson) Model S-64E type 
certificate, certificated in any category.

(b) Unsafe Condition

    This AD defines the unsafe condition as fatigue cracking in a 
flight critical component, failure of the component, and subsequent 
loss of control of the helicopter.

(c) Affected ADs

    This AD supersedes AD 97-19-10, Amendment 39-10130 (62 FR 47933, 
September 12, 1997).

(d) Compliance

    You are responsible for performing each action required by this 
AD within the specified compliance time unless it has already been 
accomplished prior to that time.

(e) Required Actions

    (1) Before further flight, for each part listed in Table 1 to 
paragraph (e) of this AD:
    (i) Remove any part that has reached or exceeded its newly 
established or revised retirement life.
    (ii) Record the newly established or revised retirement life for 
each part on the component history card or equivalent record.
    (iii) Make pen and ink changes or insert a copy of this AD into 
the Airworthiness Limitations section of the maintenance manual to 
establish or revise the retirement life for each part that is listed 
in Table 1 of this AD.

                                       Table 1 to Paragraph (e) of This AD--Parts With New or Revised Life Limits
--------------------------------------------------------------------------------------------------------------------------------------------------------
             Part name                                   Part number (P/N)                                           Retirement life
--------------------------------------------------------------------------------------------------------------------------------------------------------
Rod and bushing assembly, main       6410-21090-012...........................................  5,700 hours time-in-service (TIS) or 60 months since the
 rotor (M/R).                                                                                    initial installation on any helicopter, whichever
                                                                                                 occurs first.
Rod and bushing assembly, M/R......  6410-21090-013 or -014...................................  5,700 hours TIS.
Lower plate, M/R hub...............  6410-23009-102...........................................  3,000 hours TIS.
Upper plate, M/R hub...............  6410-23011-102...........................................  3,000 hours TIS.
Swashplate, rotating, M/R..........  6410-24002-101...........................................  12,860 hours TIS.
Piston rod.........................  6410-26005-104...........................................  10,500 hours TIS.
Cylinder, damper assembly..........  6410-26215-101...........................................  7,300 hours TIS.
M/R blade..........................  6415-20201-045 or -047...................................  3,300 hours TIS.
M/R blade..........................  6415-20201-048, -049, -050, or -051......................  20,000 hours TIS.
Truss assembly, stabilizer.........  6420-66250-041...........................................  4,720 hours TIS.
M/R shaft assembly (includes shaft,  6435-20078-014 or -015...................................  2,600 hours TIS.
 P/N 6435-20078-104).
M/R shaft assembly (includes shaft,  6435-20078-016...........................................  5,000 hours TIS.
 P/N 6435-20078-105).
Second stage planetary plate         6435-20231-012, -014, or -015............................  1,300 hours TIS.
 assembly, main gearbox assembly.
Second stage planetary plate         6435-20231-016...........................................  2,600 hours TIS.
 assembly, main gearbox assembly.
Oil cooler and support assembly....  6435-60050-044...........................................  9,885 hours TIS.
Tail rotor (T/R) blade.............  65160-00001-042, -045, or -048...........................  23,300 hours TIS.
T/R blade..........................  65161-00001-042..........................................  23,300 hours TIS.
Hub, M/R...........................  S1510-23001-005..........................................  3,000 hours TIS.
Spindle assembly, M/R..............  S1510-23027-5............................................  5,675 hours TIS.
Horn assembly, M/R.................  S1510-23350-4, -6, or -8.................................  9,710 hours TIS.
Sleeve, M/R........................  S1510-23351-2............................................  12,930 hours TIS.
Sleeve lockwasher, M/R.............  S1510-23458-0............................................  2,700 hours TIS.
Cuff, M/R blade....................  S1515-20320-0............................................  6,410 hours TIS.
Cuff, M/R blade....................  S1515-20320-001 or -002..................................  12,930 hours TIS.
Piston assembly, M/R tandem servo..  S1565-20443-0 or S1565-20443-301.........................  8,100 hours TIS.
Fork assembly, M/R tandem servo....  S1565-20449 or S1565-20449-301...........................  8,100 hours TIS.
Bearing, T/R drive shaft...........  SB1111-004 or -601.......................................  1,000 hours TIS or 12 months while installed on any
                                                                                                 helicopter, whichever occurs first.
--------------------------------------------------------------------------------------------------------------------------------------------------------


    Note to Table 1 to paragraph (e) of this AD:  The list of parts 
in Table 1 to paragraph (e) of this AD contains only a portion of 
the life-limited parts for this model helicopter and is not an all-
inclusive list.

    (2) Before further flight, remove from service any part with a 
P/N listed in Table 2 to Paragraph (e) of this AD, regardless of

[[Page 31867]]

the part's TIS. The part numbers listed in Table 2 to paragraph 
(e)(2) of this AD are not eligible for installation on any 
helicopter.

  Table 2 to Paragraph (e) of This AD--Parts To Be Removed From Service
------------------------------------------------------------------------
               Part name                               P/N
------------------------------------------------------------------------
Rod and bushing assembly, M/R..........  6410-21090-011
M/R blade..............................  6415-20001-013, -014, or -015
Pylon stabilizer.......................  6420-66201-010, -014, or -015
M/R shaft assembly.....................  6435-20078-013
Oil cooler and support assembly........  6435-60050-043
Pitch change link, rotary rudder.......  65113-07100-046
Spindle, M/R blade.....................  S1510-23070-3
------------------------------------------------------------------------

    (3) Within 20 hours TIS, and thereafter at intervals not to 
exceed 20 hours TIS, visually inspect each M/R servo and control arm 
assembly, P/N S1565-20421-10, -11, -041, or -043, and determine if 
there is any oil leaking from the M/R tandem servo housing assembly 
(servo housing), P/N S1565-20252-2. If there is any oil leaking from 
the servo housing, before further flight, replace the M/R servo and 
control arm assembly.
    (4) Within 20 hours TIS or before reaching 1,120 hours TIS, 
whichever occurs later, and thereafter at intervals not to exceed 
200 hours TIS or 12 months, whichever occurs first, ultrasonic (UT) 
inspect each M/R hub horizontal hinge pin (hinge pin), P/N S1510-
23099-1 or P/N S1510-23099-001, for a crack in accordance with the 
Accomplishment Instructions, paragraphs 2.A through 2.C, of Erickson 
Service Bulletin (SB) No. 64B10-3, Revision D, dated October 15, 
2007, except you are not required to contact Erickson nor send hinge 
pins to them. A non-destructive testing (NDT) UT Level I Special, 
Level II, or Level III inspector who is qualified under the 
guidelines established by ASNT SNT-TC-1A, ISO 9712, or an FAA-
accepted equivalent qualification standard for NDT inspection and 
evaluation, must perform the UT inspection.
    (5) Within 150 hours TIS or before reaching 1,450 hours TIS, 
whichever occurs later, perform a fluorescent-magnetic particle 
inspection (MPI) of each second stage planetary plate assembly, P/N 
6435-20231-016, for a crack.
    (6) Within 150 hours TIS or before reaching 1,450 hours TIS, 
whichever occurs later, and thereafter at intervals not to exceed 
650 hours TIS, perform an MPI of each M/R shaft, P/N 6435-20078-104, 
for a crack, paying particular attention to the lower spline area.
    (7) Within 150 hours TIS or before reaching 1,450 hours TIS, 
whichever occurs later, and thereafter at intervals not to exceed 
1,450 hours TIS, perform an MPI of each M/R shaft, P/N 6435-20078-
105, for a crack, paying particular attention to the lower spline 
area.
    (8) Within 150 hours TIS or before reaching 3,375 hours TIS, 
whichever occurs later, and thereafter at intervals not to exceed 
3,375 hours TIS, perform a fluorescent penetrant inspection of each 
housing lug on each servo housing, P/N S1565-20252-2, for a crack.
    (9) At each overhaul of the main gearbox assembly, P/N 6435-
20400-053, -054, -058, -060, -062, -063, -064, -065, or -066, 
perform an MPI of the entire shaft of each M/R shaft assembly, P/N 
6435-20078-014, -015, or -016, for a crack, paying particular 
attention to the rotating swashplate spherical bearing ball travel 
area, which is located approximately ten inches above the upper 
roller bearing journal shoulder.
    (10) If there is a crack in any part, before further flight, 
replace the cracked part.
    (11) At each overhaul of the damper assembly, P/N 6410-26200-
042, replace the following parts with airworthy parts that have zero 
(0) hours TIS:
    (i) All Air Force-Navy Aeronautical Standard (AN), Aerospace 
Standard (AS), Military Standard (MS), and National Aerospace 
Standard (NAS) nuts, bolts, washers, and packings, except packing, 
P/N MS28775-011, installed on stud, P/N SHF111-11SN-12A;
    (ii) Lock washer, P/N SS5073-2;
    (iii) Nut, P/N SS5081-05;
    (iv) Felt seal, P/N S1510-26017;
    (v) Retaining ring, P/N UR106L; and
    (vi) Nut, P/N 6410-26214-101.

(f) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Rotorcraft Certification Office, FAA, may 
approve AMOCs for this AD. Send your proposal to: Michael Kohner, 
Aerospace Engineer, Rotorcraft Certification Office, Rotorcraft 
Directorate, FAA, 2601 Meacham Blvd., Fort Worth, TX 76137; 
telephone (817) 222-5170; email 7-avs-asw-170@faa.gov.
    (2) For operations conducted under a 14 CFR part 119 operating 
certificate or under 14 CFR part 91, subpart K, we suggest that you 
notify your principal inspector, or lacking a principal inspector, 
the manager of the local flight standards district office or 
certificate holding district office before operating any aircraft 
complying with this AD through an AMOC.

(g) Additional Information

    Erickson Service Bulletin (SB) No. 64B General-1, Revision 19, 
dated September 15, 2010, which is not incorporated by reference, 
contains additional information about the subject of this AD. For 
service information identified in this AD, contact Erickson Air-
Crane Incorporated, ATTN: Chris Erickson/Compliance Officer, 3100 
Willow Springs Rd, PO Box 3247, Central Point, OR 97502, telephone 
(541) 664-5544, fax (541) 664-2312, email address 
cerickson@ericksonaircrane.com. You may review a copy of this 
information at the FAA, Office of the Regional Counsel, Southwest 
Region, 2601 Meacham Blvd., Room 663, Fort Worth, Texas 76137.

(h) Subject

    Joint Aircraft Service Component (JASC) Code: 6200: Main Rotor 
System; 6300: Main Rotor Drive System; 6410: Tail Rotor Blades; 
6500: Tail Rotor Drive System.

    Issued in Fort Worth, Texas, on May 17, 2013.
Kim Smith,
Directorate Manager, Rotorcraft Directorate, Aircraft Certification 
Service.
[FR Doc. 2013-12523 Filed 5-24-13; 8:45 am]
BILLING CODE 4910-13-P


