[Federal Register Volume 72, Number 6 (Wednesday, January 10, 2007)]
[Rules and Regulations]
[Pages 1139-1141]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-40]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-25824; Directorate Identifier 2004-SW-23-AD; 
Amendment 39-14876; AD 2007-01-05]
RIN 2120-AA64


Airworthiness Directives; Sikorsky Aircraft Corporation Model S-
61L, N, R, and NM Helicopters

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) for 
the specified Sikorsky Aircraft Corporation (Sikorsky) model 
helicopters that requires, within a specified time, creating a 
component history card or equivalent record. The AD also requires 
recording the hours time-in-service (TIS) and the external lift cycles 
(lift cycles) for each main gearbox input left and right freewheel unit 
(IFWU) assembly. Also, the AD requires calculating a moving average of 
lift cycles per hour TIS at specified intervals on each IFWU assembly. 
The moving average is used to determine if an IFWU assembly is used in 
repetitive external lift (REL) or non-REL helicopter operations. If an 
IFWU assembly is used in REL operations, this AD requires a visual and 
dimensional inspection of the IFWU assembly at specified intervals. 
This AD also requires recording certain information and replacing each 
part that is beyond the wear limits or that exhibits visual surface 
distress with an airworthy part. In addition, this AD requires 
permanently marking the REL IFWU camshafts and gear housings with the 
letters ``REL'' on the surface of these parts. This amendment is 
prompted by an accident in which the left and right IFWU assembly on a 
helicopter slipped or disengaged resulting in both engines over 
speeding, engine shutdowns, and loss of engine power to the 
transmissions. The actions specified by this AD are intended to prevent 
slipping in the IFWU assembly, loss of engine power to the 
transmissions, and subsequent loss of control of the helicopter.

DATES: Effective February 14, 2007.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of February 14, 2007.

ADDRESSES: You may get the service information identified in this AD 
from Sikorsky Aircraft Corporation, Attn: Manager, Commercial Tech 
Support, 6900 Main Street, Stratford, Connecticut 06614, phone (203) 
386-3001, fax (203) 386-5983.

Examining the Docket

    You may examine the docket that contains this AD, any comments, and 
other information on the Internet at http://dms.dot.gov, or at the 
Docket Management System (DMS), U.S. Department of Transportation, 400 
Seventh Street, SW., Room PL-401, on the plaza level of the Nassif 
Building, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Kirk Gustafson, Aviation Safety 
Engineer, Boston Aircraft Certification Office, Engine and Propeller 
Directorate, FAA, 12 New England Executive Park, Burlington, MA 01803, 
telephone (781) 238-7190, fax (781) 238-7170.

SUPPLEMENTARY INFORMATION: A proposal to amend 14 CFR part 39 to 
include an AD for the specified model helicopters was published in the 
Federal Register on September 15, 2006 (71 FR 54443). That action 
proposed to require, within a specified time, creating a component 
history card or equivalent record and counting and recording the hours 
TIS and the lift cycles for each IFWU assembly. A lift cycle is defined 
as an external load lift and subsequent release of that load. Also, the 
AD proposed calculating a moving average of lift cycles per hour TIS at 
specified intervals on the IFWU assembly. The moving average would 
determine if an IFWU assembly is designated as an REL or non-REL IFWU 
assembly. Once an IFWU assembly is designated as an REL IFWU assembly, 
the moving average would no longer need to be calculated for that IFWU 
assembly. For an IFWU assembly designated as an REL IFWU assembly, the 
AD proposed a repetitive visual and dimensional inspection of the IFWU 
assembly at 500 hours TIS or 7500 lift cycles whichever occurs first. 
The AD proposed recording inspection information, providing a copy of 
the information to the FAA, and replacing each part that is beyond the 
wear or surface distress limits with an airworthy part. In addition, 
the AD proposed permanently marking the IFWU camshaft and gear housing 
with the letters ``REL'' on the surface of these parts.
    Sikorsky has issued Alert Service Bulletin No. 61B35-67B, Revision 
B, dated August 11, 2003 (ASB). The ASB specifies implementing a moving 
average procedure for determining REL

[[Page 1140]]

status. Tracking lift cycles and the moving average procedure is 
contained in Sikorsky All Operators Letter CCS-61-AOL-04-0005. Further, 
the ASB describes procedures for establishing an inspection interval 
for REL and non-REL operations, which are defined in section 1.B. of 
the ASB. The ASB defines operations as REL when the average number of 
lift cycles exceeds 6 per flight hour during any 250 flight-hour period 
based on a moving average calculated at intervals not to exceed 50 
hours of operations. The ASB defines operations as non-REL when the 
number of moving average lift cycles per hour is 6 or less.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received. Sikorsky states there are three typographical 
errors in the NPRM. Under the heading ``Discussion,'' paragraph 3, 
Alert Service Bulletin No. 61835-67B should be 61B35-67B, and All 
Operators Letter CCS-61AOL-04-0005 should be CCS-61-AOL-04-0005. Also, 
in the Compliance Section, within the last sentence in paragraph (d) 
``with oil'' should read ``and oil.'' The FAA agrees that the three 
typographical errors should be corrected in this AD.
    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require adopting the rule 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.
    We estimate that this AD will affect 21 helicopters of U.S. 
registry and will take about:
    <bullet> 4 work hours to measure and record the inspected 
dimensions;
    <bullet> 1 work hour to mark the REL parts;
    <bullet> 3 work hours per year per helicopter to do the cycle 
counting, recording the lift cycle count, and inspecting each IFWU 
assembly;
    <bullet> Cost about $80 per work hour; and
    <bullet> Cost about $600 to replace the IFWU rollers and $980 per 
helicopter to replace the IFWU Oilite bushings at each overhaul.
    Based on these figures, the estimated total cost impact of the AD 
on U.S. operators will be $46,620, assuming you replace the IFWU 
rollers and Oilite bushings on every helicopter and every IFWU assembly 
is determined to be an REL IFWU assembly based on the first lift cycle 
calculation.

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 the 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 an economic evaluation of the estimated costs to comply 
with this AD. See the DMS to examine the 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, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends part 39 of 
the Federal Aviation Regulations (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. Section 39.13 is amended by adding a new airworthiness directive to 
read as follows:

2007-01-05 Sikorsky Aircraft Corporation: Amendment 39-14876. Docket 
No. FAA-2006-25824; Directorate Identifier 2004-SW-23-AD.

Applicability

    Model S-61L, N, R, and NM helicopters, certificated in any 
category.

Compliance

    Required as indicated.
    To prevent slipping of the main gearbox input freewheel unit 
(IFWU) assembly, loss of engine power, and subsequent loss of 
control of the helicopter, do the following:
    (a) Within 10 hours time-in-service (TIS), (1) Create an 
external lift component history card or equivalent record for each 
IFWU assembly, part number (P/N) 61074-35000-041 through 61074-
35000-063, unless accomplished previously, and
    (2) Count and, at the end of each days operations, record the 
number of external lift cycles (lift cycles) performed and the hours 
TIS. A ``lift cycle'' is defined as the lifting of an external load 
and subsequent release of the load.
    (b) Determine whether the IFWU assembly is an REL or non-REL 
IFWU assembly by using a 250-hour TIS moving average as follows:
    (1) Upon reaching 250 hours TIS after the effective date of this 
AD, calculate the first moving average of lift cycles by following 
the instructions in Section I of Appendix I of this AD.
    (i) If the calculation under paragraph (b)(1) of this AD results 
in more than 6 lift cycles per hour TIS, the IFWU assembly is an REL 
IFWU assembly.
    (ii) If the calculation under paragraph (b)(1) of this AD 
results in 6 or less lift cycles per hour TIS, the IFWU assembly is 
a Non-REL IFWU assembly.
    (2) If you determine the IFWU assembly is a Non-REL IFWU 
assembly based on the first calculation of the 250-hour TIS moving 
average for lift cycles, thereafter at intervals of 50 hour TIS, 
recalculate the average lift cycles per hour TIS by following the 
instructions in Section II of Appendix 1 of this AD.
    (i) If the calculation under paragraph (b)(2) of this AD results 
in more than 6 lift cycles per hour TIS, the IFWU assembly is an REL 
IFWU assembly.
    (ii) If the calculation under paragraph (b)(2) of this AD 
results in 6 or less lift cycles per hour TIS, the IFWU assembly is 
a Non-REL IFWU assembly.
    (3) Once an IFWU assembly is determined to be an REL IFWU 
assembly, it remains an REL IFWU assembly for the rest of its 
service life and is subject to the AD inspection requirements for 
REL IFWU assemblies.
    (4) Once an IFWU assembly is determined to be an REL IFWU 
assembly, you no longer need to perform the 250-hour TIS moving 
average calculation, but you must continue to count and record the 
lift cycles.


[[Page 1141]]


    Note 1: Sikorsky Aircraft Corporation issued an All Operators 
Letter (AOL) CCS-61-AOL-04-0005, dated May 18, 2004, with an example 
and additional information about tracking cycles and the moving 
average procedure. You can obtain this AOL from the manufacturer at 
the address stated in the ADDRESSES portion of this AD.

    (c) For each REL IFWU assembly, at intervals not to exceed 500 
hours TIS or 7500 lift cycles, whichever occurs first, since the 
last IFWU assembly inspection:
    (1) Inspect for wear, surface distress, and endplay by following 
paragraphs B.(1) through B.(6) of the Accomplishment Instructions of 
Sikorsky Aircraft Corporation Alert Service Bulletin No. 61B35-67B, 
Revision B, dated August 11, 2003 (ASB). Record all the information 
specified in Figures 1 through 3 attached to the ASB. You may record 
this information on any suitable maintenance record, or you may use 
the Sikorsky evaluation forms provided in the ASB. This AD does not 
require you to contact Sikorsky.
    (2) Replace any IFWU assembly part whose average wear, wear 
marks, surface distress, or endplay exceeds the limits stated in 
paragraph B.(1) through B.(6) of the Accomplishment Instructions of 
the ASB with an airworthy IFWU assembly part.

    Note 2: Sikorsky S-61 Overhaul Manual, Number SA 4045-83, 
Revision 20, dated August 15, 2003, as revised by Temporary 
Revisions 65-193, -194, -195, and -196, contains the overhaul 
procedures for the IFWU assembly.

    (d) For each REL IFWU assembly, permanently mark IFWU camshafts, 
P/N S6135-20611, S6135-20614 and S6137-23075, and IFWU gear 
housings, P/N S6135-20695 and S6137-23057, with the letters ``REL''. 
Mark the camshafts by applying etching ink on the surface of the 
part that is 0.5 inch square with the depth of the letters not to 
exceed 0.001 inch. After etching, neutralize the etched surface and 
oil to prevent corrosion.
    (e) For the next 24 months and within 10 days after completing 
the requirements of paragraph (c)(1) of this AD, provide a copy of 
the recorded information to the Manager of the Boston Aircraft 
Certification Office, Engine and Propeller Directorate, FAA, 12 New 
England Executive Park, Burlington, MA 01803.

    Note 3: In the ASB, Sikorsky requests copies of the completed 
inspection forms, Figures 1 through 3 to their ASB. This AD does not 
require you to provide these forms to Sikorsky.

    (f) Information collection requirements contained in this AD 
have been approved by the Office of Management and Budget (OMB) 
under the provisions of the Paperwork Reduction Act of 1980 (44 
U.S.C. 3501 et seq.) and have been assigned OMB Control Number 2120-
0056.
    (g) 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 Manger, Boston Aircraft Certification Office, Engine and 
Propeller Directorate, FAA, ATTN: Kirk Gustafson, Aviation Safety 
Engineer, 12 New England Executive Park, Burlington, MA 01803, 
telephone (781) 238-7190, fax (781) 238-7170, for information about 
previously approved alternative methods of compliance.
    (h) The inspections shall be done by following the specified 
portions of Sikorsky Aircraft Corporation Alert Service Bulletin No. 
61B35-67B, Revision B, dated August 11, 2003. The Director of the 
Federal Register approved this incorporation by reference in 
accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be 
obtained from Sikorsky Aircraft Corporation, Attn: Manager, 
Commercial Tech Support, 6900 Main Street, Stratford, Connecticut 
06614, phone (203) 386-3001, fax (203) 386-5983. Copies may be 
inspected 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/code_of_federal_regulations/ibr_locations.html.
    (i) This amendment becomes effective on February 14, 2007.

Appendix I

    Section I: The first moving average of lift cycles per hour TIS.
    The first moving average calculation is performed on the IFWU 
assembly when the external lift component history card record 
reflects that the IFWU assembly has reached its first 250 hours TIS. 
To perform the calculation, divide the total number of lift cycles 
performed during the first 250 hours TIS by 250. The result will be 
the first moving average calculation of lift cycles per hour TIS.
    Section II: Subsequent moving average of lift cycles per hour 
TIS.
    Subsequent moving average calculations are performed on the IFWU 
assembly at intervals of 50 hour TIS after the first moving average 
calculation. Subtract the total number of lift cycles performed 
during the first 50-hour TIS interval used in the previous moving 
average calculation from the total number of lift cycles performed 
on the IFWU assembly during the previous 300 hours TIS. Divide this 
result by 250. The result will be the next or subsequent moving 
average calculation of lift cycles per hour TIS.
    Section III: Sample calculation for subsequent 50 hour TIS 
intervals.
    Assume the total number of lift cycles for the first 50 hour TIS 
interval used in the previous moving average calculation = 450 lift 
cycles and the total number of lift cycles for the previous 300 
hours TIS = 2700 lift cycles. The subsequent moving average of lift 
cycles per hour TIS = (2700-450) divided by 250 = 9 lift cycles per 
hour TIS.

    Issued in Fort Worth, Texas, on December 26, 2006.
David A. Downey,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. E7-40 Filed 1-9-07; 8:45 am]
BILLING CODE 4910-13-P