Federal Register / Vol. 75, No. 92 / Thursday, May 13, 2010 / Rules and Regulations 26885 

(2) EMBRAER Model ERJ 190–100 ECJ, 

–100 LR, –100 IGW, –100 STD, –200 STD, 

–200 LR, and –200 IGW airplanes, equipped 

with outboard slat skew sensor P/N 

1702286A or 1702288A. 

Subject 

(d) Air Transport Association (ATA) of 

America Code 57: Wings. 

Reason 

(e) The mandatory continuing 

airworthiness information (MCAI) states: 

‘‘It has been found the occurrence of 

outboard slat skew sensor failure in open or 

closed position. The combination of an 

outboard slat skew sensor failed closed, an 

outboard slat actuator structural failure 

(rupture) and its adjacent actuator torque 

limiter failing high (allows higher loads to 

the panel structure) occurring in the same 

slat surface, under normal flight loads, may 

lead [the] slat surface to detach from the wing 

with the possibility of hitting and damaging 

the horizontal stabilizer and elevator, which 

may affect the airplane controllability.’’ 

* * * * * 

Corrective actions include repetitive 

operational tests of the outboard slat skew 

sensor, and replacement with a serviceable 

outboard slat skew sensor if necessary. 

Actions and Compliance 

(f) Unless already done, do the following 

actions. 

(1) At the applicable compliance time in 

paragraph (f)(1)(i) or (f)(1)(ii) of this AD: 

Perform an operational test (OPT) of any 

outboard slat skew sensor having P/N 

1702286A or P/N 1702288A. If any outboard 

slat skew sensor fails the test, replace the 

sensor with a serviceable sensor before 

further flight. Do the actions using a method 

approved by either the Manager, 

International Branch, ANM–116, Transport 

Airplane Directorate, FAA; or the Ageˆncia 

Nacional de Aviac ̧a ̃o Civil (ANAC) (or its 

delegated agent). 

(i) For Model ERJ 170 airplanes: Within 

1,320 flight hours after the effective date of 

this AD. 

(ii) For Model ERJ 190 airplanes: Within 

1,320 flight hours or 12 months after the 

effective date of this AD, whichever occurs 

first. 

Note 1: Guidance on performing the OPT 

required by paragraph (f)(1) of this AD can 

be found in Task 27–83–01–710–801–A, 

‘‘Outboard Slat Skew Sensor—Operational 

Test,’’ dated October 28, 2008, of the Embraer 

170/175 or 190 Aircraft Maintenance Manual 

(AMM). 

Note 2: For the purpose of this AD, an OPT 

is ‘‘A task to determine if an item is fulfilling 

its intended purpose. Since it is a failurefinding task, it does not require quantitative 

tolerances.’’ 

Note 3: For the purpose of this AD, a 

serviceable sensor is one that has passed the 

OPT required by paragraph (f)(1) of this AD. 

(2) Repeat the OPT required by paragraph 

(f)(1) of this AD thereafter at intervals not to 

exceed 1,320 flight hours. 

FAA AD Differences 

Note 4: This AD differs from the MCAI 

and/or service information as follows: No 

differences. 

Other FAA AD Provisions 

(g) The following provisions also apply to 

this AD: 

(1) Alternative Methods of Compliance 

(AMOCs): The Manager, International 

Branch, ANM–116, Transport Airplane 

Directorate, FAA, has the authority to 

approve AMOCs for this AD, if requested 

using the procedures found in 14 CFR 39.19. 

Send information to ATTN: Kenny Kaulia, 

Aerospace Engineer, International Branch, 

ANM–116, Transport Airplane Directorate, 

FAA, 1601 Lind Avenue, SW., Renton, 

Washington 98057–3356; telephone (425) 

227–2848; fax (425) 227–1149. Before using 

any approved AMOC on any airplane to 

which the AMOC applies, notify your 

principal maintenance inspector (PMI) or 

principal avionics inspector (PAI), as 

appropriate, or lacking a principal inspector, 

your local Flight Standards District Office. 

The AMOC approval letter must specifically 

reference this AD. 

(2) Airworthy Product: For any requirement 

in this AD to obtain corrective actions from 

a manufacturer or other source, use these 

actions if they are FAA-approved. Corrective 

actions are considered FAA-approved if they 

are approved by the State of Design Authority 

(or their delegated agent). You are required 

to assure the product is airworthy before it 

is returned to service. 

(3) Reporting Requirements: For any 

reporting requirement in this AD, under the 

provisions of the Paperwork Reduction Act 

(44 U.S.C. 3501 et seq.), the Office of 

Management and Budget (OMB) has 

approved the information collection 

requirements and has assigned OMB Control 

Number 2120–0056. 

Related Information 

(h) Refer to MCAI Brazilian Airworthiness 

Directives 2009–02–02 and 2009–02–03, both 

effective February 16, 2009, for related 

information. 

Material Incorporated by Reference 

(i) None. 

Issued in Renton, Washington, on April 28, 

2010. 

Ali Bahrami, 

Manager, Transport Airplane Directorate, 

Aircraft Certification Service. 

[FR Doc. 2010–10900 Filed 5–12–10; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2006–24587; Directorate 

Identifier 2006–SW–05–AD; Amendment 39– 

16281; AD 2010–10–02] 

RIN 2120–AA64 

Airworthiness Directives; Sikorsky 

Aircraft Corporation Model S–76A, B, 

and C Helicopters 

AGENCY: Federal Aviation 

Administration, DOT. 

ACTION: Final rule. 

SUMMARY: This amendment adopts a 

new airworthiness directive (AD) for 

Sikorsky Aircraft Corporation (Sikorsky) 

Model S–76A, B, and C helicopters that 

requires inspecting each installed 

Woodward HRT (formerly HR Textron) 

main rotor servo actuator (servo 

actuator) for a high rate of leakage and 

replacing each affected servo actuator 

with a servo actuator containing a newly 

re-designed servo actuator piston. This 

amendment is prompted by a National 

Transportation Safety Board (NTSB) 

Safety Recommendation issued in 

response to an accident involving a 

Model S–76C helicopter. In the NTSB 

Safety Recommendation, the 

performance of a servo actuator piston 

upon reaching 3,000 hours time-inservice (TIS) was questioned as a result 

of piston head seal leakage and piston 

head plasma spray flaking. The actions 

specified by this AD are intended to 

prevent degraded servo actuator 

performance as a result of piston head 

seal leaking and plasma spray flaking, 

which could result in subsequent loss of 

control of the helicopter. 

DATES: Effective June 17, 2010. 

ADDRESSES: You may get the service 

information identified in this AD from 

Sikorsky Aircraft Corporation, Attn: 

Manager, Commercial Technical 

Support, 6900 Main Street, Stratford, 

Connecticut, phone (203) 383–4866, email address tsslibrary@sikorsky.com. 

Examining the Docket: You may 

examine the docket that contains this 

AD, any comments, and other 

information on the Internet at http:// 

www.regulations.gov, or at the Docket 

Operations office, West Building 

Ground Floor, Room W12–140, 1200 

New Jersey Avenue, SE., Washington, 

DC. 

FOR FURTHER INFORMATION CONTACT: 

Terry Fahr, Aviation Safety Engineer, 

Boston Aircraft Certification Office, 12 

New England Executive Park, 


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26886 Federal Register / Vol. 75, No. 92 / Thursday, May 13, 2010 / Rules and Regulations 

Burlington, MA 01803, telephone (781) 

238–7155, fax (781) 238–7170. 

SUPPLEMENTARY INFORMATION: A revised 

proposal to amend 14 CFR part 39 to 

include an AD for Sikorsky Model S– 

76A, B, and C helicopters was published 

in the Federal Register on February 11, 

2009 (74 FR 6835). That action, a 

supplemental notice of proposed 

rulemaking (SNPRM), proposed to 

require inspecting each installed servo 

actuator for a high rate of leakage, and 

if there is a high rate of leakage, 

replacing the servo actuator piston or 

replacing the servo actuator. The 

SNPRM also proposed replacing each 

affected servo actuator piston, part 

number (P/N) 41004321 or 

RW41004321, upon reaching 3,000 

hours TIS, with a newly-designed servo 

actuator piston, P/N 41012001, or 

replacing an affected servo actuator with 

a servo actuator containing a newlydesigned servo actuator piston. That 

action revised our previous proposal, 

issued on April 21, 2006, which was 

published in the Federal Register on 

May 2, 2006 (71 FR 25783), and which 

proposed to require inspecting the 

hydraulic fluid for contamination; 

removing the requirement to reduce the 

interval for overhauling an affected 

servo actuator from 3,000 to 2,000 hours 

TIS; revising the initial inspection time; 

and removing the 600 hours TIS 

repetitive hydraulic fluid leak 

inspection. 

Interested persons have been afforded 

an opportunity to participate in the 

making of this amendment. Due 

consideration has been given to the 

three comments received in response to 

the SNPRM. Comments submitted in 

response to the NPRM were addressed 

in the SNPRM. 

One commenter, Copterline Oy, states 

through their law firm that the design of 

the overhauled servo actuator piston 

head has not been approved by the FAA 

and is therefore not airworthy. They 

state that the cause of an accident 

involving a Sikorsky Model S–76 

helicopter, which occurred on August 

10, 2005, was plasma flaking from the 

piston head of the pistons in the 

forward servo actuator, which quickly 

led to a deterioration of the seals that 

are intended to prevent leakage. The 

commenter also states that ‘‘testing for 

leakage at 500 or even 100 hour 

intervals will not provide any assurance 

that the servo actuator will function 

even few hours after the test has been 

performed.’’ They conclude that ‘‘all 

unairworthy servo actuators with 

plasma coating lapped over and across 

the head of the piston should be 

removed from service immediately’’, and 

that ‘‘helicopters with these servo 

actuators should not be designated as 

airworthy and, accordingly, should be 

grounded and not permitted to operate.’’ 

We do not agree with the commenter 

that helicopters with the overhauled 

servo pistons in the servo actuator 

should be grounded because that makes 

them unairworthy. The overhaul of the 

pistons was accomplished under the 

authority of the repair station of the 

Sikorsky servo piston supplier using 

overhaul data acceptable to the FAA. 

The plasma coating work performed on 

the overhauled piston was a 

maintenance activity performed under 

the Woodward HRT (formerly HR 

Textron) overhaul procedures approved 

by Sikorsky and according to acceptable 

practices. The purpose of these overhaul 

procedures was to restore the piston 

head to its original design 

specifications. Our review of the service 

history of the Model S–76 helicopters 

prior to the August 2005 accident found 

no incidents of loss of control of a 

helicopter as a result of servo actuator 

leakage or plasma spray flaking. 

However, because of safety concerns 

surrounding the overhaul of these two 

servo pistons and the plasma spray 

flaking, this AD requires phasing these 

overhauled pistons out of service. No 

later than 3,000 hours TIS or upon 

discovering fluid leakage exceeding 700 

cc per minute, any overhauled piston 

must be replaced with a non-overhauled 

piston—either P/N 41012001–001, that 

has improved bonding qualities, or P/N 

41012001. When these non-overhauled 

pistons are installed, the –109 and –110 

servo actuators must be re-identified as 

either Sikorsky or Woodward HRT –111 

servo actuators. It is our intent that, 

although the servo actuator piston may 

no longer be overhauled, the servo 

actuator may be overhauled using a nonoverhauled piston. Thus, the –109 and 

–110 servo actuators are being phased 

out along with overhauled servo 

pistons. 

A second commenter, the NTSB, 

states: ‘‘When checking servo actuators 

for contamination and leakage, the 

inspections must be redundant enough 

and the inspection intervals short 

enough to ensure that missing a problem 

during any single inspection does not 

result in a potential catastrophic failure 

of the aircraft.’’ They state that we 

should require overhauling any affected 

servo actuator at intervals of 2,000 hours 

TIS, and require a 600 hours TIS 

repetitive hydraulic fluid leak 

inspection, as stated in the proposed AD 

that we issued on April 21, 2006 (71 FR 

25783, May 2, 2006). 

We do not agree. Our review of the 

Model S–76 helicopter service history 

data prior to the August 2005 accident 

found no evidence of a helicopter 

control issue associated with servo 

actuator leakage or plasma spray flaking. 

Therefore, we believe that requiring an 

additional leakage rate inspection at 

1,500 hours TIS, and, if leakage 

exceeding 700 cc per minute is found, 

requiring replacement of the servo 

actuator piston or replacement of the 

servo actuator with an airworthy servo 

actuator is sufficient to prevent 

degraded servo actuator performance as 

a result of piston head seal leaking and 

plasma spray flaking. 

A third commenter, Sikorsky, states 

that they support ‘‘the majority of this 

SNPRM.’’ However, they suggest that we 

replace ‘‘HR Textron’’ with their new 

name, ‘‘Woodward HRT’’; include, 

‘‘reworked piston’’, P/N RW41004321, 

for removal; and add replacement 

piston, Woodward HRT P/N 4102001– 

001. Our understanding is that a 

‘‘reworked piston’’ is the same as an 

‘‘overhauled piston.’’ We agree and have 

made those changes. 

Sikorsky further states that the 1,500 

hours check represents a new restrictive 

requirement to Chapter 4 of the 

Airworthiness Limitations and 

Inspection Requirements (ALIR). The 

1,500 hours time-since-new (TSN) or 

time-since-overhaul (TSO) action in the 

AD is an ‘‘inspection’’ that must be 

performed by a mechanic, not a ‘‘check’’ 

that we sometimes allow a pilot to 

perform. We agree that this revises the 

airworthiness limitations of the 

maintenance manual, and we have 

placed a statement indicating that in the 

AD. Further, Sikorsky states that this 

‘‘check’’ should be performed in 

accordance with the maintenance 

manual. Because we have not specified 

an alternative manner for performing 

this ‘‘inspection’’, you must use a 

procedure that is acceptable to the FAA, 

which most probably will be the 

procedures stated in the maintenance 

manual. This is true of any maintenance 

action on all products. It is generally 

understood, and need not be stated in 

every AD. Therefore, no change is being 

made to the AD based on this comment. 

The substance of other general 

comments by Sikorsky has been 

addressed in the SNPRM. 

After careful review of the available 

data, including the comments noted 

above, the FAA has determined that air 

safety and the public interest require the 

adoption of the rule, with the previously 

stated changes. 

We estimate that this AD will affect 

300 helicopters (900 servo actuators) of 

U.S. registry. We also estimate that the 

leakage rate inspection will take about 

1 work hour per servo actuator at an 


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Federal Register / Vol. 75, No. 92 / Thursday, May 13, 2010 / Rules and Regulations 26887 

average labor rate of $85 per work hour, 

and the two leakage rate inspections on 

900 servo actuators will cost about 

$153,000. We estimate that 6 servo 

actuators, Sikorsky P/N 76650–09805– 

109 or –110, will need to be replaced 

with servo actuators, Sikorsky P/N 

76650–09805–111. Assuming an 

estimated 8 work hours per servo 

actuator for installation and a cost of 

$57,000 per servo actuator, the total cost 

of installing these servo actuators will 

be $346,080. We estimate that the cost 

of replacing the pistons in the remaining 

894 servo actuators will cost $7,321,860, 

assuming 14 work hours to replace the 

pistons and install the servo actuator, 

and a cost of $3,500 per piston (2 

pistons per servo). Therefore, the total 

estimated cost of this AD is $7,820,940. 

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 AD docket 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, Safety. 

Adoption of the Amendment 

■ 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 

■ 1. The authority citation for part 39 

continues to read as follows: 

Authority: 49 U.S.C. 106(g), 40113, 44701. 

§ 39.13 [Amended] 

■ 2. Section 39.13 is amended by adding 

a new airworthiness directive to read as 

follows: 

2010–10–02 Sikorsky Aircraft Corporation: 

Amendment 39–16281. Docket No. 

FAA–2006–24587; Directorate Identifier 

2006–SW–05–AD. 

Applicability: Model S–76A, B, and C 

helicopters, with a main rotor servo actuator 

(servo actuator), Sikorsky Aircraft 

Corporation (Sikorsky) part number (P/N) 

76650–09805–109 or –110 (also marked as 

HR Textron or Woodward HRT P/N 

3006760–109 or –110), installed, certificated 

in any category. 

Compliance: Required as indicated, unless 

accomplished previously. 

To detect leaking in a servo actuator, 

which could lead to degraded servo actuator 

performance and subsequent loss of control 

of the helicopter, do the following: 

(a) For a servo actuator with 1,500 or less 

hours time since new (TSN) or time since 

overhaul (TSO), determine the leakage rate 

on or before reaching 1,500 hours TSN or 

TSO. This 1,500 hour TSN or TSO inspection 

revises the airworthiness limitations section 

of the applicable maintenance manual. 

(b) For a servo actuator with 2,250 or less 

hours TSN or TSO, but more than 1,500 

hours TSN or TSO, determine the leakage 

rate on or before reaching 2,250 hours TSN 

or TSO. 

(c) If the leakage rate in any servo actuator 

exceeds 700 cc per minute when performing 

the leakage rate inspection specified in 

paragraph (a) or (b) of this AD, then: 

(1) Replace that servo actuator piston, HR 

Textron or Woodward HRT P/N 41004321 or 

P/N RW41004321, with a servo actuator 

piston, P/N 41012001 or P/N 41012001–001, 

and re-identify the servo actuator on the 

servo actuator data plate as Sikorsky P/N 

‘‘76650–09805–111’’ and Woodward HRT 

P/N ‘‘3006760–111’’ using a metal stamp 

method; or 

(2) Replace the servo actuator with an 

airworthy servo actuator, Sikorsky P/N 

76650–09805–111, Woodward HRT P/N 

3006760–111. 

(d) On or before 3,000 hours TSN or TSO, 

whichever occurs first, replace each servo 

actuator piston and re-identify the servo 

actuator as specified in paragraph (c)(1) of 

this AD or replace each servo actuator as 

specified in paragraph (c)(2) of this AD. 

(e) Modifying and re-identifying each servo 

actuator as specified in paragraph (c)(1) of 

this AD or replacing each servo actuator as 

specified in paragraph (c)(2) of this AD is 

terminating action for the requirements of 

this AD for the modified and re-identified or 

replaced servo actuator. 

(f) 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, Boston Aircraft 

Certification Office, FAA, ATTN: Terry Fahr, 

Aviation Safety Engineer, 12 New England 

Executive Park, Burlington, MA 01803, 

telephone (781) 238–7155, fax (781) 238– 

7170, for information about previously 

approved alternative methods of compliance. 

(g) The Joint Aircraft System/Component 

(JASC) Code is 6730: Rotorcraft Servo 

System. 

(h) This amendment becomes effective on 

June 17, 2010. 

Issued in Fort Worth, Texas, on April 27, 

2010. 

Mark R. Schilling, 

Acting Manager, Rotorcraft Directorate, 

Aircraft Certification Service. 

[FR Doc. 2010–10588 Filed 5–12–10; 8:45 am] 

BILLING CODE 4910–13–P 


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