FAA PROPELLERS

Apparent engine roughness is often a result of propeller unbalance. The effect of an unbalanced propeller will usually be. approximately the same at all speeds. greater at low RPM. greater at high RPM.

On twin engine aircraft, the propeller autofeather system is activated when. rudder forces increase beyond a set value during an engine-out condition. a propeller overspeed condition is detected. engine power loss results in a propeller thrust drop to a preset value.

The primary reason for careful inspection and prompt repairing of minor surface defects such as scratches, nicks, gouges, etc. on aluminum alloy propellers is to prevent. corrosion. unbalanced aerodynamics. fatigue failure.

The centrifugal twisting moment of an operating propeller tends to. increase the pitch angle. reduce the pitch angle. bend the blades in the direction of rotation.

Propeller blade tracking is the process of determining. the plane of rotation of the propeller with respect to the aircraft longitudinal axis. that the blade angles are within the specified tolerance of each other. the positions of the tips of the propeller blades relative to each other.

What operational force causes propeller blade tips to lag in the opposite direction of rotation?. Thrust-bending force. Aerodynamic-twisting force. Torque-bending force.

Longitudinal (fore and aft) clearance of constant-speed propeller blades or cuffs must be at least 1/2 inch (12.7 mm) between propeller parts and stationary parts of the aircraft. This clearance is with the propeller blades. at takeoff pitch (maximum thrust) angle. feathered or in the most critical pitch configuration. at the lowest pitch angle.

Manually feathering a hydromechanical propeller means to. block governor oil pressure to the cylinder of the propeller. port governor oil pressure to the cylinder of the propeller. port governor oil pressure from the cylinder of the propeller.

A fixed-pitch wooden propeller that has been properly installed and the attachment bolts properly torqued exceeds the out-of-track allowance by 1/16 inch. The excessive out-of-track condition may be corrected by. slightly overtightening the attachment bolts adjacent to the most forward blade. discarding the propeller since out-of-track conditions cannot be corrected. placing shims between the inner flange and the propeller.

How does the propeller overspeed governor on a turboprop engine decrease propeller RPM?. When oil pressure is decreased, the return spring and counterweights force the oil out of the servo piston. As oil pressure increases, the servo piston is pushed forward, and the feather spring is compressed. When oil pressure is increased, the return spring and counterweights force the oil out of the servo piston.

The primary purpose of the front and rear cones for propellers that are installed on splined shafts is to. position the propeller hub on the splined shaft. prevent metal-to-metal contact between the propeller and the splined shaft. reduce stresses between the splines of the propeller and the splines of the shaft.

A constant-speed propeller provides maximum efficiency by. increasing blade pitch as the aircraft speed decreases. adjusting blade angle for most conditions encountered in flight. increasing the lift coefficient of the blade.

The propeller governor controls the. oil to and from the pitch changing mechanism. spring tension on the boost pump speeder spring. linkage and counterweights from moving in and out.

Generally, unless otherwise specified by the manufacturer, repairs of nicks, scratches, gouges, etc., on aluminum propeller blades must be made. parallel to the length of the blade. perpendicular to the blade axis. so as to return the damaged area to the original dimensions.

During which of the following conditions of flight will the blade pitch angle of a constant-speed propeller be the greatest?. Approach to landing. Climb following takeoff. High-speed, high-altitude cruising flight.

Propeller blade station numbers increase from. hub center line to tip. tip to hub center line. blade shank butt to tip.

Minor surface damage located in a repairable area, but not on the leading or trailing edges of aluminum blades, may be repaired by first. filing with a riffle file. filing with a half round or flat file. rough sanding and applying a proper filler.

What type of imbalance will cause a two-blade propeller to have a persistent tendency to come to rest in a horizontal position (with the blades parallel to the ground) while being checked on a propeller balancing beam?. Vertical. Horizontal. Harmonic.

Most engine-propeller combinations have one or more critical ranges within which continuous operation is not permitted. Critical ranges are established to avoid. severe propeller vibration. low or negative thrust conditions. inefficient propeller pitch angles.

How is aircraft electrical power for propeller deicer systems transferred from the engine to the propeller hub assembly?. By slip rings and segment plates. By slip rings and brushes. By flexible electrical connectors.

What is the basic purpose of the three small holes (No. 60 drill) in the tipping of wood propeller blades?. To provide a means for inserting balancing shot when necessary. To provide a means for periodically impregnating the blade with preservation materials. To allow the moisture which may collect between the tipping and the wood to escape (vent the tipping).

Which of the following defects is cause for rejection of wood propellers?. Dye penetrant inspection failure. Bonding or separation of the trailing edge of the propeller blade. Delamination found by conducting a tap test.

Which of the following best describes the blade movement of a feathering propeller that is in the HIGH RPM position when the feathering action is begun?. High pitch through low pitch to feather position. Low pitch through reverse pitch to feather position. Low pitch through high pitch to feather position.

How is anti-icing fluid ejected from the slinger ring on a propeller?. By pump pressure. By centripetal force. By centrifugal force.

The primary purpose of a propeller is to. create lift on the fixed airfoils of an aircraft. change engine horsepower to thrust. provide static and dynamic stability of an aircraft in flight.

Which of the following generally renders an aluminum alloy propeller unrepairable?. Blade face surface damage. Leading or trailing edge damage. Transverse cracks of any size.

The pitch-changing mechanism of the hydromatic propeller is lubricated by. the pitch-changing oil. using an approved-type grease in a grease gun at intervals prescribed by the propeller manufacturer. thoroughly greasing, necessary only during propeller overhaul.

Propellers exposed to salt spray should be flushed with. engine oil. fresh water. soapy water.

The aerodynamic force acting on a rotating propeller blade operating at a normal pitch angle tends to. reduce the pitch angle. increase the pitch angle. bend the blades rearward in the line of flight.

For takeoff, a constant-speed propeller is normally set in the. HIGH PITCH, high RPM position. HIGH PITCH, low RPM position. LOW PITCH, high RPM position.

When preparing a propeller blade for inspection it should be cleaned with. mild soap and water. steel wool. methyl ethyl ketone.

A propeller synchrophasing system allows a pilot to reduce noise and vibration by. adjusting the phase angle between the propellers on an aircraft's engines. adjusting the plane of rotation of all propellers. setting the pitch angle of all propellers exactly the same.

Which of the following methods is used to straighten a bent aluminum propeller blade that is within repairable limits?. Careful heating to accomplish straightening, followed by heat treatment to restore original strength. Either hot or cold straightening, depending on the location and severity ot damage. Never straighten a damaged propeller.

The thrust produced by a rotating propeller is a result of. an area of low pressure behind the propeller blades. an area of decreased pressure immediately in front of the propeller blades. the angle of relative wind and rotational velocity of the propeller.

Flyweights on constant-speed propellers are generally used to aid in. increasing blade angle. decreasing blade angle. unfeathering the propellers.

After proper removal of aluminum blade damage, the affected surface should be polished with. fine steel wool or scotch-brite. very fine sandpaper or crocus cloth. soapstone or wire brush.

What operational force tends to bend the propeller blades forward at the tip?. Torque-bending force. Centrifugal-twisting force. Thrust-bending force.

Propeller fluid anti-icing systems generally use which of the following?. Ethylene glycol. Isopropyl alcohol. Ethyl alcohol.

What action takes place when the flight deck control lever for a hydromatic, constant-speed propeller is actuated?. Compression of the speeder spring is changed. The governor booster pump pressure is varied. The governor bypass valve is positioned to direct oil pressure to the propeller dome.

What is indicated when the front cone bottoms while installing a propeller?. Propeller-dome combination is incorrect. Blade angles are incorrect. Rear cone should be moved forward.