[Federal Register Volume 71, Number 179 (Friday, September 15, 2006)]
[Proposed Rules]
[Pages 54443-54446]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-15331]


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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-25824; Directorate Identifier 2004-SW-23-AD]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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

SUMMARY: This document proposes adopting a new airworthiness directive 
(AD) for the specified Sikorsky Aircraft Corporation (Sikorsky) model 
helicopters. The AD would require, within a specified time, creating a 
component history card or equivalent record. The AD would also require 
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 would require calculating a moving 
average of lift cycles per hour TIS at specified intervals on each IFWU 
assembly. The moving average would be 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 would require a repetitive inspection, which requires a visual 
and dimensional inspection of the IFWU assembly at specified intervals. 
This AD would also require 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 would 
require permanently marking the REL IFWU camshafts and gear housings 
with the letters ``REL'' on the surface of these parts. This proposal 
is prompted by an accident in which the left and right IFWU assembly on 
a helicopter slipped or disengaged resulting in both engines 
overspeeding, engine shutdowns, and loss of engine power to the 
transmissions. The actions specified by the proposed 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: Comments must be received on or before November 14, 2006.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD:
     DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically;
     Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically;
     Mail: Docket Management Facility; U.S. Department of 
Transportation, 400

[[Page 54444]]

Seventh Street, SW., Nassif Building, Room PL-401, Washington, DC 
20590;
     Fax: 202-493-2251; or
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street, SW., Washington, DC, 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 Sikorsky Aircraft Corporation, Attn: Manager, Commercial Tech 
Support, 6900 Main Street, Stratford, Connecticut 06614, phone (203) 
386-3001, fax (203) 386-5983.
    You may examine the comments to this proposed AD in the AD docket 
on the Internet at http://dms.dot.gov.

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:

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-2006-
25824, Directorate Identifier 2004-SW-23-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://dms.dot.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 Management 
System (DMS) Docket Office between 9 a.m. and 5 p.m., Monday through 
Friday, except Federal holidays. The Docket Office (telephone 1-800-
647-5227) is located at the plaza level of the Department of 
Transportation NASSIF Building in Room PL-401 at 400 Seventh Street, 
SW., Washington, DC. Comments will be available in the AD docket 
shortly after the DMS receives them.

Discussion

    This document proposes adopting a new AD for the specified Sikorsky 
model helicopters. The AD would 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 would require 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. REL operations are those 
operations in which more than 6 lift cycles per hour TIS are performed 
based on the moving average. Non-REL operations are those operations in 
which 6 or less lift cycles per hour TIS are performed based on the 
moving average. 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. If an IFWU assembly is designated as an REL IFWU 
assembly, this AD would require a repetitive visual and dimensional 
inspection of the IFWU assembly at 500 hours TIS or 7500 lift cycles 
whichever occurs first. This AD would also require 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, this AD would require permanently 
marking the IFWU camshaft and gear housing with the letters ``REL'' on 
the surface of these parts.
    The proposal is prompted by an accident in which the left and right 
IFWU assembly on a helicopter slipped or disengaged resulting in both 
engines overspeeding, engine shutdowns, and loss of engine power to the 
transmissions. The main cause of the slippage has been traced to 
excessive and accelerated wear conditions in the IFWU assembly 
associated with repeated external lifting operations. The actions 
specified by the proposed 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.
    We have reviewed Sikorsky Alert Service Bulletin No. 61835-67B, 
Revision B, dated August 11, 2003 (ASB). The ASB specifies implementing 
a moving average procedure for determining REL status. Tracking lift 
cycles and the moving average procedure is contained in Sikorsky All 
Operators Letter CCS-61AOL-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.
    This unsafe condition is likely to exist or develop on other 
helicopters of the same type designs. Therefore, the proposed AD would 
require the following:
     Within 10 hours TIS,
     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 done previously, and
     Count and, at the end of each day's operations, record the 
number of lift cycles performed and hours TIS.
     Determine whether the IFWU assembly is an REL or non-REL 
IFWU assembly by using a 250-hour TIS moving average as follows:
     Upon reaching 250 hours TIS, calculate the first moving 
average of lift cycles.
     If the calculation results in more than 6 lift cycles per 
hour TIS, the IFWU assembly is an REL IFWU assembly.
     If the calculation results in 6 or less lift cycles per 
hour TIS, the IFWU assembly is a Non-REL IFWU assembly.
     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 hours TIS, 
recalculate the average lift cycles per hour TIS.
     If the calculation results in more than 6 lift cycles per 
hour TIS, the IFWU assembly is an REL IFWU assembly.
     If the calculation results in 6 or less lift cycles per 
hour TIS, the IFWU assembly is a Non-REL IFWU assembly.
     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

[[Page 54445]]

and is subject to the AD inspection requirements for REL IFWU 
assemblies.
     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.
     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, inspect for wear, surface distress, and 
endplay, record the information; and
     Replace any IFWU assembly part whose average wear, wear 
marks, surface distress, or endplay exceeds the limits with an 
airworthy IFWU assembly part.
     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 with oil to 
prevent corrosion.
     For the next 24 months and within 10 days provide the 
recorded information required by this AD to the Manager of the Boston 
Aircraft Certification Office, Engine and Propeller Directorate, FAA, 
12 New England Executive Park, Burlington, MA 01803.
    The actions would be required by following specified portions of 
the ASB described previously.
    We estimate that this proposed AD would affect 21 helicopters of 
U.S. registry and would take about:
     4 work hours to measure and record the inspected 
dimensions,
     1 work hour to mark the REL parts, and
     3 work hours per year per helicopter to do the cycle 
counting, recording the lift cycle count, and inspecting each IFWU 
assembly, and
     Cost about $80 per work hour.
     Required parts would 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 total cost impact of the proposed AD on 
U.S. operators would 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 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 analysis of the estimated costs to 
comply with this proposed AD. See the DMS to examine the draft economic 
analysis.

Authority for This Rulemaking

    The FAA's authority to issue rules regarding aviation safety is 
found in Title 49 of the United States Code. 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.
    This rulemaking is promulgated under the authority described in 
subtitle VII, part A, subpart III, section 44701, ``General 
requirements.'' Under that section, the FAA is charged 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 AD.

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:

Sikorsky Aircraft Corporation: 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 54446]]


    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 with 
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.

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 intervals 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 September 8, 2006.
David A. Downey,
Manager, Rotorcraft Directorate, Aircraft Certification Service.
 [FR Doc. E6-15331 Filed 9-14-06; 8:45 am]
BILLING CODE 4910-13-P