Transcript Wright Aviation Services LLC Presents Piper Meridian Systems Training Program Propeller System ©2010-2011-Wright Aviation Services, LLC All rights reserved 1/10/11 Click Mouse to Advance Wright Aviation Services Meridian – PA46-500TP Propeller 1/10/11 Click.

Wright Aviation Services LLC
Presents
Piper Meridian
Systems Training Program
Propeller System
©2010-2011-Wright Aviation Services, LLC
All rights reserved
1/10/11
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Meridian – PA46-500TP
Propeller
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Meridian – PA46-500TP
Propeller
Hartzell (HC E4N-3Q/ER501K-3.5)
 Four Blades
 Constant Speed
 All Aluminum
 Electrically Heated
 Full Feathering
 Reversible
System Includes
 Turbine Driven
 Reduction Gearbox
 Hydraulic Governor
 Overspeed Governor
 Hub Assembly
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Meridian – PA46-500TP
Propeller
Pitch Limits
 Low Pitch .......... 19.0° ±0.1°
 Max Reverse ..... -10.0° ±0.5°
 Feather ............. 84.5° ±0.5
Diameter
 81.5 minimum
 82.5 maximum
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Meridian – PA46-500TP
Propeller
Operating Modes
 Normal
 Beta
 Reverse
Governing System
 Primary Governor
 Spring
 Counterweights
 Oil Pressure
 Fuel Pressure
 Overspeed Governor
 Spring
 Counterweights
 Oil Pressure
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Meridian – PA46-500TP
Propeller
Primary Governor uses a combination of spring & counterweights offset by oil
pressure to regulate propeller RPMs (Np) to 2000. The spring & counterweight act
to increase propeller pitch while oil pressure acts to decrease the pitch.
In a simplified explanation, an oil boost pump incorporated into the primary
governor is controlled by the throttle using linkages and fuel pressure. As the
throttle moves, changes position and in fuel pressure cause changes in governor oil
pressure allowing the pitch of the blades to increase or decrease to maintain a
constant speed in normal operations. These linkages are also involved in the low
power operations including BETA and Reverse.
The counterweights and spring (know as the feather spring) work to cause the
blades to go into feather with the loss of oil, pressure at shut down, or when
commanded.
The overspeed governor manages the top end of the Np range by preventing
the prop from exceeding 2000 rpms. It is can be manually activated from the
cockpit to provide a secondary means of controlling a runaway prop should there
be an uncommanded spike in oil pressure that would reduce blade pitch, increasing
Np. Loss of oil pressure, on the other hand, would cause the blades to increase
pitch on the way to feathering.
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Meridian – PA46-500TP
OnSpeed
 2000 rpms
A balance is struck
between the feather
spring & counterweights
and the oil pressure on
the back of the piston to
produce a constant 2000
rpms
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Meridian – PA46-500TP
Primary
Governor
Overspeed
Governor
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Meridian – PA46-500TP
Over Speed

> 2000 rpms
To prevent overspeed, this
governor releaves pressure to
guard against blade pitch
reductions which could result in
Np exceedances. In a potential
overspeed condition the feather
spring & counterweights act to
increase pitch by releasing oil
pressure to maintain a constant
2000 rpms.
A electrically actuated valve
provides a manually over ride
capability from the cockpit.
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Meridian – PA46-500TP
Underspeed
 < 2000 rpms
Any reduction in RPMs
results in reduced centrifical
force on the counterweights
allowing the oil pressure to
overcome the feather spring,
reducing the blade pitch until
equalibrium is achieved.
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Meridian – PA46-500TP
Overspeed Governor
The in the event of an
uncontrolled overspeed condition,
the overspeed governor can be
manually activated, reducing oil
pressure into the prop hub
causing the blades to increase
pitch and control rpms. Testing of
this system is conducted during
the before take off portion of the
normal procedures.
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Meridian – PA46-500TP
Review
Hartzell (HC E4N-3Q/ER501K-3.5)
 Four Blades
 Constant Speed
 Full Feathering
 Reversable
Speed
 2000 rpms
Diameter
 81.5 minimum
 82.5 maximum
Governors
 Primary
 Overspeed
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Meridian Propeller
THE END
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Presented by
Wright Aviation Services LLC
Scottsdale/Phoenix AZ
Copyright 2010/2011 – Wright Aviation Services
All rights reserved
Website: www.wrightaviation.net
Email: [email protected]
Phone: 480-203-0599
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