Explanations: Propellers Flashcards
What is a rheostat?
a variable resistor.
How are propeller electric deicing boots checked for operation?
By observing the ammeter or load meter for the proper amount of current flow, and by feeling the boots to see if they are heating.
Follow the sequence of boot heating by feeling the boots with your hand to determine that each one is heating. The boots should all have a similar heat rise in the same length of time.
What is propeller synchrophasing?
Like a synchroniser, the synchrophaser also compares the propeller to the propeller position of the propeller blades within their individual arcs and then adjusts them to their optimum relative positions.
What is a phase angle?
For example, if one propeller is positioned vertically with the tips facing the sky and the ground, and the second propeller were positioned horizontally, the phase angle would be 90 degrees.
When should a final balancing check be made after allowing the finish on a wooden prop to dry?
at least 48 hours after finish application.
What is the primary cause of aerodynamic imbalance?
when the thrust of one blade is greater than the thrust of the other. This can be corrected with contouring and angle setting.
What is a constant-speed propeller?
A propeller than changes pitch angle, not RPM, to adjust speed. It also automatically adjust pitch angle according to whether the plane is ascending or descending, in order to maintain constant speed.
sort of…
What is a high vs low pitch propeller?
A higher pitch (coarse) is a karate chop. A lower pitch (fine) is a high five.
What are the control spring (speeder spring) and flyweights in a propeller governor?
The control spring is what the pilot actuates to try and maintain a desired RPM. They put pressure on the flyweights which spin outward depending on the RPM of the crankshaft. Essentially, as the RPM increases, the flyweights move outward, causing the pitch to increase. and vis versa.
What is engine manifold pressure?
It is the air pressure in an engine’s intake manifold.
What does the pulley stop screw do?
It limits the maximum amount the speeder spring is allowed to compress, limiting the maximum amount of RPM achievable.
What is the “on-speed” condition of a propeller?
the state in which the propeller is operating at its designed optimal RPM and pitch angle for a given flight condition.
What is a full feathering propeller?
A propeller that can be pitched to a near 90 degrees blade pitch.
What is front cone bottoming?
a condition in which the front propeller cone contacts the ends of the shaft splines.
Shaft splines are
