Wright Aviation Services LLC Presents Piper Meridian Systems Training Program Propeller System...

Click Mouse to Advance Wright Aviation Services

1

Wright Aviation Services LLCPresents

Piper MeridianSystems Training Program

Propeller System©2010-2011-Wright Aviation Services, LLC

All rights reserved

1/10/11


2

Meridian – PA46-500TPPropeller

1/10/11


3


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

1/10/11


4


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

1/10/11


5


Operating Modes Normal Beta Reverse

Governing System Primary Governor

Spring Counterweights Oil Pressure Fuel Pressure

Overspeed Governor Spring Counterweights Oil Pressure

1/10/11


6


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.

1/10/11


7

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

1/10/11


8


Primary Governor

OverspeedGovernor

1/10/11


9


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.

1/10/11


10


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.

1/10/11


11


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.

1/10/11


12


ReviewHartzell (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

1/10/11


13

Meridian Propeller

THE END

1/10/11


14

Presented byWright Aviation Services LLC

Scottsdale/Phoenix AZCopyright 2010/2011 – Wright Aviation Services

All rights reservedWebsite: www.wrightaviation.net

Email: [email protected]: 480-203-0599

1/10/11

http://www.wrightaviation.net/

mailto:[email protected]

Wright Aviation Services LLC Presents Piper Meridian Systems Training Program Propeller System...

Documents

Transcript of Wright Aviation Services LLC Presents Piper Meridian Systems Training Program Propeller System...