Document ID: FAA-2007-0373-0001
Agency: faa
Document Type: Rule
Title: Airworthiness Directives; Erickson Air-Crane Incorporated Model S-64E and S-64F Helicopters
Posted Date: 2007-12-31T05:00Z

[Federal Register: December 31, 2007 (Volume 72, Number 249)]
[Proposed Rules]               
[Page 74210-74213]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr31de07-14]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2007-0373; Directorate Identifier 2006-SW-14-AD]
RIN 2120-AA64

 
Airworthiness Directives; Erickson Air-Crane Incorporated Model 
S-64E and S-64F Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes adopting a new airworthiness directive 
(AD) for the specified Erickson Air-Crane Incorporated (Erickson) model 
helicopters. The AD would require determining whether each specified 
tail rotor blade assembly (blade assembly) has an affected serial 
number or part marking. If a blade assembly has a certain serial number 
or part marking, the AD would also require initially and repetitively 
inspecting the tail rotor blade for a crack in the strap and pocket 
areas. If a crack is found, this AD would also require, before further 
flight, replacing the blade assembly with an airworthy blade assembly 
that does not have an affected serial number or part marking. This 
proposal is prompted by several reports of cracking in the strap and 
pocket areas of the tail rotor blade. The actions specified by the 
proposed AD are intended to prevent failure of the tail rotor blade and 
subsequent loss of control of the helicopter.

DATES: Comments must be received on or before February 29, 2008.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD:

[[Page 74211]]

     Federal eRulemaking Portal: Go to http://www.regulations.gov.
 Follow the instructions for submitting comments.

     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590.
     Hand Delivery: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays.
    You may get the service information identified in this proposed AD 
from Erickson Air-Crane Incorporated, P. O. Box 3247, Central Point, OR 
97502, telephone 541-664-5544, fax 541-664-2312, or at http://www.ericksonaircrane.com
.

    You may examine the comments to this proposed AD in the AD docket 
on the Internet at http://www.regulations.gov.

FOR FURTHER INFORMATION CONTACT: Michael Kohner, Aviation Safety 
Engineer, FAA, Rotorcraft Directorate, Rotorcraft Certification Office, 
Fort Worth, Texas 76193-0170, telephone (817) 222-5447, fax (817) 222-
5783.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to submit any written data, views, or arguments 
regarding this proposed AD. Send your comments to the address listed 
under the caption ADDRESSES. Include the docket number ``FAA-2007-0373, 
Directorate Identifier 2006-SW-14-AD'' at the beginning 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 rulemaking. Using the 
search function of our docket web site, you can find and read the 
comments to any of our dockets, including the name of the individual 
who sent or signed the comment. You may review the DOT's complete 
Privacy Act Statement in the Federal Register published on April 11, 
2000 (65 FR 19477-78) or you may visit http://dms.dot.gov.

Examining the Docket

    You may examine the docket that contains the proposed AD, any 
comments, and other information in person at the Docket Operations 
office between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Operations office (telephone (800) 647-5527) is 
located in Room W12-140 on the ground floor of the West Building at the 
street address stated in the ADDRESSES section. Comments will be 
available in the AD docket shortly after receipt.

Discussion

    This document proposes adopting a new AD for the specified Erickson 
model helicopters. The AD would require determining whether certain 
tail rotor blade assemblies have an affected serial number or part 
marking. If a blade assembly has a certain serial number or part 
marking, the AD would also require initially and repetitively 
inspecting the tail rotor blade for a crack in the strap and pocket 
areas. If a crack is found, this AD would also require, before further 
flight, replacing the blade assembly with an airworthy blade assembly 
that does not have an affected serial number or part marking. This 
proposal is prompted by several reports of cracking in the strap or 
pocket areas of the tail rotor blade. This condition, if not corrected, 
could result in failure of the tail rotor blade and subsequent loss of 
control of the helicopter.
    We have reviewed Erickson Alert Service Bulletin 64B15-9, Revision 
B, dated October 6, 2006 (ASB), which describes procedures for 
determining and inspecting certain marked or serial numbered tail rotor 
blades. The ASB specifies repetitive inspections not to exceed 6 flight 
hours for the S-64F model and not to exceed 15 flight hours for the S-
64E model. Alternate inspection schedules are also included for ``ferry 
flights'' used for delivering the helicopter from one area of operation 
to another. The ``ferry flight'' time would be the flight time 
beginning at the end of the last operation in one area to the beginning 
of the first operation in another area. If a crack is found in the 
strap or pocket, the ASB specifies removing and replacing the blade.
    We propose to depart from the language of the ASB and propose to 
use the terms hours time-in-service (TIS) instead of maximum ground-
air-ground (GAG) cycles. We propose to define a ``ferry flight'' as a 
helicopter flight used for delivering the helicopter from one area of 
operation to another. During the ``ferry flight'' the helicopter would 
not drop off an external load or pick up an external load. A GAG cycle 
as defined in the ASB for the purposes of these inspections is any 
maneuver that results in a climb-out similar to one following takeoff. 
The proposed inspection intervals for the ferry flights were also 
modified to accommodate a new range of values based on specifications 
supplied by Erickson. The proposed inspection intervals were determined 
by multiplying the maximum GAG cycles in the ASB for the given takeoff 
weight by the flight endurance of 2.5 hours TIS for the Model S-64E and 
2.2 hours TIS for the Model S-64F helicopters and rounding the result 
to a near whole number as deemed appropriate.
    This unsafe condition is likely to exist or develop on other 
helicopters of these same type designs. Therefore, the proposed AD 
would require for each blade assembly, part number (P/N) 65161-00001-
042 or -043, the following actions:
     Within 25 hours TIS, unless done previously, determine if 
the blade assembly has a serial number listed in the ASB. Also, 
determine if the blade assembly is marked with an ``RS503'' near the 
part number.
     If the blade assembly serial number is not listed in the 
ASB and does not have ``RS503'' marked near the part number, no further 
action would be required by this AD.
     If a blade assembly has either an affected serial number 
or part marking, before further flight, using a 10-power or higher 
magnifying glass, inspect both sides of the blade assembly for a crack 
in the strap and pocket areas paying particular attention to the 
circled area as depicted in Figure 1 of the ASB.
     If no crack is found, inspect the blade assembly at 
intervals not to exceed those TIS intervals specified in Table 1 of the 
AD.
     If a crack is found, before further flight, replace the 
unairworthy blade assembly with an airworthy FAA approved blade 
assembly that does not have a serial number listed in the ASB and does 
not have ``RS503'' marked near the part number.
    The actions would be required to be done by following the specified 
portions of the ASB described previously.
    We estimate that this proposed AD would:
     Affect 20 helicopters of U.S. registry; 13 Model S-64E and 
7 Model S-64F;
     Require about 1 work hour to determine whether an affected 
blade is installed;
     Require about 1 work hour to inspect the blade assembly, 
assuming about 40 inspections a year for each Model S-64E (total 520) 
and about 100

[[Page 74212]]

inspections a year for each Model S-64F (total 700);
     Require about 4 work hours to replace each tail rotor 
blade, assuming 10 tail rotor blade assemblies are replaced;
     Cost about $80 per work hour; and
     Cost about $60,000 per blade assembly.
    Based on these figures, the estimated total cost impact of the 
proposed AD on U.S. operators would be $702,400, based on the stated 
assumptions.

Regulatory Findings

    We have determined that this proposed AD would not have federalism 
implications under Executive Order 13132. Additionally, 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. 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 draft economic evaluation of the estimated costs to 
comply with this proposed AD. See the DMS to examine the draft economic 
evaluation.

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.

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. Section 39.13 is amended by adding a new airworthiness directive 
to read as follows:

    Erickson Air-Crane Incorporated: Docket No. FAA-2007-0373; 
Directorate Identifier 2006-SW-14-AD.

Applicability

    Model S-64E and S-64F helicopters, with tail rotor blade 
assembly (blade assembly), part number (P/N) 65161-00001-042 or -
043, installed, certificated in any category.

Compliance

    Required as indicated.
    To prevent failure of the tail rotor blade and subsequent loss 
of control of the helicopter, do the following:
    (a) Within 25 hours time-in-service (TIS), unless accomplished 
previously:
    (1) Determine if the blade assembly has a serial number listed 
in the Accomplishment Instructions, paragraph 2.A., of Erickson Air-
Crane Incorporated Alert Service Bulletin No. 64B15-9, Revision B, 
dated October 6, 2006 (ASB). Also, determine if the blade assembly 
has ``RS503'' marked near the P/N.
    (2) If the blade assembly serial number is not listed in the ASB 
and does not have ``RS503'' marked near the P/N, no further action 
is required by this AD.
    (3) If a blade assembly has either a serial number listed in 
paragraph 2.A of the ASB or has ``RS503'' marked near the part 
number, before further flight, using a 10-power or higher magnifying 
glass, inspect both sides of the blade assembly for a crack in the 
strap and pocket areas paying particular attention to the circled 
area as depicted in Figure 1 of the ASB.
    (i) If no crack is found, inspect the blade assembly as 
specified in paragraph (a)(3) of this AD at intervals not to exceed 
those shown in the following table:

                                 Table 1
------------------------------------------------------------------------
                                                           Maximum time
                                   Gross takeoff weight       between
          Mission type                    (lbs)             inspections
                                                            (hours TIS)
------------------------------------------------------------------------
         Model S-64E Tail Rotor Blade Strap Inspection Intervals
------------------------------------------------------------------------
Ferry Only.....................  Above 35,000...........              30
Ferry Only.....................  Above 30,000 and less                35
                                  than or equal to
                                  35,000.
Ferry Only.....................  Below or equal to                    40
                                  30,000.
All Others.....................  All....................              15
------------------------------------------------------------------------
         Model S-64F Tail Rotor Blade Strap Inspection Intervals
------------------------------------------------------------------------
Ferry Only.....................  Above 35,000...........               8
Ferry Only.....................  Above 30,000 and less                15
                                  than or equal to
                                  35,000.
Ferry Only.....................  Below or equal to                    17
                                  30,000.
All Others.....................  All....................               6
------------------------------------------------------------------------

    Note: For the purposes of this AD, a ferry flight is defined as 
a helicopter flight used for delivering the helicopter from one area 
of operation to another. During the ferry flight, the helicopter 
would not drop off an external load or pick up an external load.

    (ii) If a crack is found, before further flight, replace the 
unairworthy blade assembly with an airworthy FAA approved blade 
assembly that does not have a serial number listed in paragraph 2.A 
of the ASB and does not have ``RS503'' marked near the P/N.

[[Page 74213]]

    (b) Installing an airworthy blade assembly that does not have a 
serial number listed in paragraph 2.A of the ASB and does not have 
``RS503'' marked near the P/N is terminating action for the 
requirements of this AD.
    (c) To request a different method of compliance or a different 
compliance time for this AD, follow the procedures in 14 CFR 39.19. 
Contact the Manager, Rotorcraft Directorate, Rotorcraft 
Certification Office, FAA, ATTN: Michael Kohner, Aviation Safety 
Engineer, Fort Worth, Texas 76193-0170, telephone (817) 222-5447, 
fax (817) 222-5783.

    Issued in Fort Worth, Texas, on November 28, 2007.
Mark R. Schilling,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. E7-25411 Filed 12-28-07; 8:45 am]

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