[Federal Register Volume 71, Number 84 (Tuesday, May 2, 2006)]
[Proposed Rules]
[Pages 25783-25785]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-6586]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-24587; Directorate Identifier 2006-SW-05-AD]
RIN 2120-AA64


Airworthiness Directives; Sikorsky Aircraft Corporation Model S-
76A, B, and C 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 Sikorsky Aircraft Corporation (Sikorsky) Model S-76A, B, and C 
helicopters. The AD would require inspecting all installed HR Textron 
main rotor servo actuators (servo actuators) for a high rate of leakage 
and also inspecting for contaminated hydraulic fluid. The AD would also 
require reducing the time-in-service (TIS) interval for overhauling the 
servo actuators. This proposal is prompted by a National Transportation 
Safety Board (NTSB) Safety Recommendation written in response to an 
accident involving a Model S-76 helicopter in which the performance of 
an HR Textron servo actuator was questioned as a result of piston head 
seal leakage and piston head plasma spray flaking. The actions 
specified by the proposed AD are intended to detect a high rate of 
leaking from a servo actuator and contamination of the hydraulic fluid, 
which could lead to degraded ability to maneuver the cyclic and 
collective controls and could result in subsequent loss of control of 
the helicopter.

DATES: Comments must be received on or before July 3, 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 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 examine the comments to this proposed AD in the AD docket 
on the Internet at http://dms.dot.gov.

FOR FURTHER INFORMATION CONTACT: Terry Fahr, Aviation Safety Engineer, 
Boston Aircraft Certification Office, 12 New England Executive Park, 
Burlington, MA 01803, telephone (781) 238-7155, fax (781) 238-7199.

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-
24587, Directorate Identifier 2006-SW-05-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

[[Page 25784]]

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 Sikorsky Model S-76A, 
B, and C helicopters with an HR Textron servo actuator, part number (P/
N) 76650-09805, installed. The AD would require inspecting all 
installed HR Textron servo actuators for leakage that exceeds 700 cc 
per minute by installing a test line in the servo actuator return port, 
and inspecting the hydraulic fluid for contamination using a patch test 
kit or an independent laboratory analysis method. If leakage in excess 
of 700 cc per minute is detected in any servo actuator, the proposed AD 
would require replacing that servo actuator with an airworthy servo 
actuator. If the hydraulic fluid is found to be contaminated, the 
proposed AD would require flushing the hydraulic system. The AD would 
also require reducing the TIS interval for overhauling an affected 
servo actuator from 3,000 to 2,000 hours TIS. This proposal is prompted 
by an NTSB Safety Recommendation written in response to an accident 
involving a Model S-76 helicopter in which the performance of an HR 
Textron servo actuator was questioned as a result of piston head seal 
leakage and piston head plasma spray flaking. The actions specified by 
the proposed AD are intended to detect a high rate of leaking from a 
servo actuator and contamination of the hydraulic fluid, which could 
lead to degraded ability to maneuver the cyclic and collective controls 
and could result in subsequent loss of control of the helicopter.
    This unsafe condition is likely to exist or develop on other 
helicopters of the same type design. Therefore, the proposed AD would 
require, within 25 hours TIS and thereafter at intervals not to exceed 
600 hours TIS, determining the leakage rate for the three servo 
actuators by installing a test line in each servo actuator return port 
and turning on the hydraulic power. If the leakage rate exceeds 700 cc 
per minute in any servo actuator, the proposed AD would require 
replacing that servo actuator with an airworthy servo actuator before 
further flight. The proposed AD would also require inspecting the 
hydraulic fluid for contamination using a patch test kit or an 
independent laboratory analysis method. If the hydraulic fluid is found 
to be contaminated, the proposed AD would require flushing the 
hydraulic system before further flight. The proposed AD would also 
require reducing the TIS interval for overhauling the servo actuator 
from 3,000 to 2,000 hours TIS.
    We estimate that this proposed AD would affect 300 helicopters of 
U.S. registry, and that
     Determining the servo actuator leakage rate would take 
approximately 8 work hours,
     Inspecting the hydraulic fluid for contamination would 
take approximately 3 work hours,
     Replacing the servo actuator, if necessary, would take 
approximately 12 work hours, and
     Flushing the hydraulic system, if necessary, would take 
approximately 6 work hours per helicopter to accomplish at an average 
labor rate of $80 per work hour. Required parts would cost 
approximately $13,000 per helicopter for a servo actuator. Based on 
these figures, the total cost impact of the proposed AD on U.S. 
operators would be $4,596,000 ($15,320 per helicopter), assuming one 
leakage inspection and one hydraulic fluid inspection on each 
helicopter, and replacing one servo actuator and flushing the hydraulic 
system on each helicopter.

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:

Sikorsky Aircraft Corporation: Docket No. FAA-2006-24587; 
Directorate Identifier 2006-SW-05-AD.

    Applicability: Model S-76A, B, and C helicopters, with HR 
Textron main rotor servo actuator (servo actuator), part number (P/
N) 76650-09805, installed, certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To detect leaking in a servo actuator and contamination of the 
hydraulic fluid, which could lead to degraded ability to maneuver 
the cyclic and collective controls and could result in subsequent 
loss of control of the helicopter, accomplish the following:
    (a) Within 25 hours time-in-service (TIS), and thereafter at 
intervals not to exceed 600 hours TIS:
    (1) Determine the leakage rate of each of the three servo 
actuators by installing a test line in each servo actuator return 
port and turning on the hydraulic power.
    (2) If the leakage rate exceeds 700 cc per minute in a servo 
actuator, before further flight, remove that servo actuator and 
replace it with an airworthy servo actuator.
    (3) Inspect the hydraulic fluid for contamination using either a 
patch test kit or an independent laboratory analysis method.
    (4) If contamination is found, before further flight, flush the 
hydraulic system and refill

[[Page 25785]]

the system with uncontaminated hydraulic fluid.
    (b) On or before reaching 2,000 hours TIS since the last 
overhaul, and thereafter at intervals not to exceed 2,000 hours TIS, 
overhaul each servo actuator, P/N part number 76650-09805, or 
replace it with an airworthy servo actuator.
    (c) This AD revises the Airworthiness Limitations and Inspection 
Requirements manual by reducing the overhaul interval for the servo 
actuator, P/N 76650-09805, from 3,000 hours TIS to 2,000 hours TIS.
    (d) 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 FAA, ATTN: Terry Fahr, Aviation Safety Engineer, Boston 
Aircraft Certification Office, 12 New England Executive Park, 
Burlington, MA 01803, telephone (781) 238-7155, fax (781) 238-7199, 
for information about previously approved alternative methods of 
compliance.

    Issued in Fort Worth, Texas, on April 21, 2006.
Mark R. Schilling,
Acting Manager, Rotorcraft Directorate, Aircraft Certification Service.
[FR Doc. E6-6586 Filed 5-1-06; 8:45 am]
BILLING CODE 4910-13-P