Props Flashcards
The thrust produced by a rotating propeller is a result of which condition?
An area of low pressure in front of the propeller blades.
Define propeller blade angle
The angle formed between the chord of the blade and the plane of rotation
Define propeller blade angle of attack
The angle formed between the chord of the blade and the relative wind.
The actual distance a propeller moves forward through the air during one revolution is known as the?
Effective Pitch
Geometric pitch of a propeller is defined as-
Effective pitch plus slippage.
What operational force causes the greatest stress on a propeller?
Centrifugal Force
What operational force tends to bend the propeller blades forward at the tip?
Thrust-bending Force
What operational force causes propeller blade tips to lag in the opposite direction of rotation?
Torque bending force
What operational force tends to increase the pitch angle?
Aerodynamic Twisting Force
Propeller blade station numbers increase from?
Hub to tip
Which of the following functions require the use of a propeller blade station?
Measuring propeller blade angle.
What is the smallest increment that can be measured with a prop protractor?
1/10 of a degree
What is the primary purpose of a cuff on a propeller blade?
Increase the flow of cooling air to the engine nacelle.
What is the purpose of the three small holes in the tipping of wood propeller blades?
To allow the moisture between the tipping and the wood to escape/vent.
Where are the high and low pitch stops of a Hamilton Standard two-position counterweight propeller located?
In the counterweight assembly.
The effect of an unbalanced propeller will be?
Greater at high RPM
What is the purpose of an arbor used in balancing a propeller?
To support the propeller on the balancing knives.
What type of imbalance will cause a two-blade propeller to come to rest in a horizontal position while being checked on a balancing beam?
Vertical
Which of the following is used to correct horizontal unbalance of a wood propeller?
Solder
The application of more protective coating on one blade than the other when refinishing a wood propeller is done for what reason?
To achieve final balancing
Whatis the primary purpose of a feathering propeller?
Eliminate the drag created by a windmilling propeller when an engine fails in flight.
Which of the following best describes the blade movement of a feathering propeller that is in the
HIGH RPM position when feathering action is begun?
Low pitch through high pitch to feather position.
During operationa/ check of an aircraft using a hydromatic full-feathering propeller, the feather button, after being pushed:
Remains depressed until the feather cycle is complete, then opens.
What normally prevents a Hartzell Compact propeller from going to feather when the engine is shut down on the ground?
A latch mechanism composed of springs and lock pins
How does a propeller synchrophasing system allow a pilot to reduce noise and vibration?
Adjusting the phase angles between the propellers on the aircraft’s engines.
Ice formation on propellers, when an aircraft is in flight, will?
Decrease thrust and cause excessive vibration.
Propeller fluid ant-icing-sistems generally use which of the following?
Isopropyl alcohol
How is anti-icing fluid ejected from the slinger ring on a propeller?
Centrifugal force
What unit in the propeller anti-icing system controls the output of the pump?
Rheostat
How is aircraft electrical power for propeller deicer systems transferred from the engine to the propeller hub assembly?
By slip rings and brushes
What actuates the pilot valve in the governor of a constant-speed propeller?
Governor flyweights
During the on-speed condition of a propeller
the centrifugal force of the governor flyweights is equal to the speeder spring force.
When the centrifugal force acting on the propeller governor flyweights overcomes tension on the speeder spring, a propeller is in what speed condition?
Over speed
Constant-speed non-feathering propellers without counterweights increase pitch angle using
Oil pressure
Counterweights on constant-speed featherable propellers are used for
Increasing blade angle
To increase power without damaging a reciprocating engine, which of the controls should be advanced first, the Throttle or Propeller Pitch Control?
Increase propeller pitch control than throttle.
What are the rotational speed and blade pitch angle requirements of a constant-speed propeller during takeoff?
High speed and low pitch angle
During what phase of flight will the blade angle of a constant-speed propeller be the greatest
High altitude cruise
What is the result of moving the throttle on a reciprocating engine when the propeller is in the constant-speed range with the engine developing cruise power?
Opening the throttle will cause an increase in blade angle.
What unit directs oil to and from the cylinder on the Hamilton Standard two-position counterweight propeller?
3 way valve
For what reason is it important to repair nicks in aluminum alloy propeller blades as soon as possible?
Eliminate stress concentration points
Repairs of nicks, scratches, and gouges on aluminum blades must be made in which manner?
Parallel to length of the blade
Which of the following generally renders an aluminum alloy propeller unrepairable?
Transverse cracks of any size
When preparing a propeller blade for inspection it should be cleaned with which of the following?
Mild soap and water
What method would be used to inspect an aluminum propeller blade when a crack is suspected?
Dye penetrant
Removal of propeller blade tips within the Type Certificate Data Sheet limits when correcting a defect is
A major repair
Repairs of aluminum alloy adjustable pitch propeller blades are not permitted in which area?
Shank
How can front cone bottoming be corrected on a splined shaft installation?
By using a spacer behind the rear cone
Which of the following determines oil and grease specifications for lubrication of propellers?
Propeller manufacturer
How is the pitch-changing mechanism of a hydromatic propeller lubricated?
With the pitch changing oil
