CSP
−
900RMM
−
2
MD Helicopters, Inc.
Rotorcraft Maintenance Manual
Page 1
Original
64-30-00
NOTAR
ANTI
−
TORQUE FAN SYSTEM
DESCRIPTION AND OPERATION
1. Anti
−
Torque System Fan Assembly
The NOTAR
®
anti-torque fan is an axial fan
with thirteen variable pitch blades. The fan
provides anti-torque by furnishing variable
flow of low pressure high volume air through
the tailboom and thrusters. The fan operation
al rpm in flight at 100% power is 5,412 rpm.
At 104% power, the fan rpm is 5,628.
The NOTAR System is designed to be a
failsafe system. Complete stoppage of the fan
will not prevent a safe autorotational landing.
A spring loaded limit capsule in the control
input to the fan retains vertical stabilizer fin
control and prevents any fan failure from
locking the remaining controls. The ability to
control the vertical stabilizer fins provides
adequate anti-torque for a safe landing.
2. Anti
−
Torque Fan Assembly Components
Fan Hub -
The fan hub is an aluminum alloy
forging centered on an angular contact
double-row ball bearing that reacts to changes
to thrust in both directions.
Center Spline Assembly -
The center spline
assembly attaches to the fan hub with thirteen
bolts and nuts. These bolts also attach the
inboard end of the tension-torsion straps to
the spline/hub assembly. The spline assembly
also provides the spline drive surfaces to mate
with the fan support driveshaft.
Tension-Torsion Straps -
Tension-torsion
straps attach the blades to the hub. The straps
react to blade centrifugal forces while provid
ing a torsional spring counteracting blade
pitch forces. The tension-torsion strap is
comprised of a continuous Kevlar filament
wound around a Corrosion Resistance Steel
Alloy (CRES) spool type bushing at each end.
Fan Blades -
Each blade is comprised of an
aluminum alloy forged spar and polypropylene
injection molded blade. The pitch horns are
aluminum alloy and hard anodized to mini
mize wear and corrosion. Attaching washers to
the counterweight arms on the spar of the
blade, and positioning of index marked
counter-weights, overcome pedal forces from
the fan. The counter-weight index marks are
factory set and adjustment is not allowed.
Fan Liner -
The fan liner felt metal seal
provides a controlled gap between the fan and
the felt metal seal for optimum efficiency of
the fan during flight.
Balance Studs -
There are thirteen balance
studs equally spaced around the fan hub.
Balancing of the fan is accomplished, with the
fan installed in the aircraft, by adding or
subtracting balance washers to the thirteen
balance studs.
Pitch Plate -
A sliding pitch plate uniformly
changes the angle of the blades through the
pitch horns which are part of the blade spar.
The pitch plate is aluminum alloy and
mounted to a stainless steel shaft which slides
inside the hub support shaft. As the pitch plate
slides with the shaft, it actuates each blade
pitch horn to control the blades. Replaceable
cuff bushings are at each pitch horn/pitch
plate interface to minimize the effects of wear.
The pitch plate rotates with the blades about a
double row ball pitch bearing.
Pitch Control -
Pitch control is applied to the
pitch plate by a stationary control rod end
through a double row ball bearing. This allows
the transition from stationary to rotating pitch
control.
Interrupter -
A steel pin is installed at one
location on the forward face of the fan hub.
This pin acts as a magnetic field interrupter
for the azimuth sensor used by the aircraft
installed balancing equipment.
Summary of Contents for CSP-900RMM-2
Page 19: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual INTRODUCTION Chapter ...
Page 20: ......
Page 23: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual Section 01 00 00 Introduction ...
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Page 223: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual DIMENSIONS AND AREAS Chapter ...
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Page 249: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual LIFTING AND JACKING Chapter ...
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Page 273: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual Section 08 20 00 Leveling ...
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Page 277: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual TOWING Chapter ...
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Page 281: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual Section 09 00 00 Towing ...
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Page 287: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual PARKING AND MOORING Chapter ...
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Page 299: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual Section 10 20 00 Mooring ...
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Page 311: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual PLACARDS AND MARKINGS Chapter ...
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Page 333: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual SERVICING Chapter ...
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Page 337: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual Section 12 00 00 Servicing ...
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Page 401: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual Section 21 20 00 Vent System ...
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Page 525: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual EQUIPMENT FURNISHINGS Chapter ...
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Page 627: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual Section 25 60 10 Rescue Hoist ...
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Page 655: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual FIRE PROTECTION Chapter ...
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Page 711: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual FUEL SYSTEM Chapter ...
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Page 721: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual Section 28 00 00 Fuel System ...
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Page 887: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual HYDRAULIC SYSTEM Chapter ...
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Page 925: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual LANDING GEAR Chapter ...
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Page 983: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual DOORS AND WINDOWS Chapter ...
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Page 1049: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual FUSELAGE Chapter ...
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Page 1063: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual Section 53 00 00 Fuselage ...
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Page 1205: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual Section 53 40 00 Tailboom ...
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Page 1235: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual Section 53 55 00 Empennage ...
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Page 1259: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual Chapter MAIN ROTOR ...
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Page 1503: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual Section 63 20 00 Gearboxes ...
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Page 1579: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual Section 63 22 00 Rotor Brake ...
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Page 1619: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual ANTI TORQUE ASSEMBLY Chapter ...
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Page 1685: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual FLIGHT CONTROLS Chapter ...
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Page 1927: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual POWERPLANT Chapter ...
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Page 1935: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual Section 71 00 00 Powerplant ...
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Page 1985: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual Section 71 20 00 Engine Mounts ...
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Page 2001: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual Section 71 60 00 Air Intake ...
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Page 2033: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual Section 71 70 00 Engine Drains ...
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Page 2043: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual ENGINE BLEED AIR Chapter ...
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Page 2053: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual ENGINE CONTROLS Chapter ...
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Page 2105: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual ENGINE EXHAUST Chapter ...
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Page 2109: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual Section 78 00 00 Engine Exhaust ...
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Page 2121: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual ENGINE OIL Chapter ...
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Page 2125: ...CSP 900RMM 2 MD Helicopters Inc Rotorcraft Maintenance Manual Section 79 00 00 Engine Oil ...
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