PROPELLERS PART 2

The angle-of-attack of a rotating propeller blade is measured between the blade chord or face and which of the following?. Plane of blade rotation. Full low-pitch blade angle. Relative airstream.

The purpose of permanently sealing and partially filling some models of McCauley propeller hubs with dyed oil is to. provide an always clean separate lubrication of the internal parts. dampen pressure surges and prevent too rapid changes in propeller blade angle. make the location of cracks readily apparent.

It is important that nicks in aluminum alloy propeller blades be repaired as soon as possible in order to. maintain equal aerodynamic characteristics between the blades. eliminate stress concentration points. equalize the centrifugal loads between the blades.

What normally prevents a Hartzell Compact propeller from going to feather when the engine is shut down on the ground?. Propeller cylinder air pressure. A latch mechanism composed of springs and lock pins. Accumulator provided oil pressure.

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.

What controls the constant-speed range of a constant-speed propeller?. Engine RPM. Angle of climb and descent with accompanying changes in airspeed. The mechanical limits in the propeller pitch range.

Which of the following statements concerning the installation of a new fixed-pitch wood propeller is true?. Inspect the bolts for proper torque after every 50 hours and annual inspection. Install and tighten the bolts to the proper torque during installation; no inspection interval after that. Inspect the bolts for proper torque after the first flight and after the first 25 hours of flying.

Which of the following defects is cause for rejection of wood propellers?. Solder missing from screw heads securing metal tipping. An oversize hub or bolt hole, or elongated bolt holes. No protective coating on propeller.

Inspection of aluminum propeller blades by dye-penetrant inspection is accomplished to detect. fatigue failure. material de-bond. warpage.

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).

On most reciprocating multiengine aircraft, automatic propeller synchronization is accomplished through the actuation of the. throttle levers. propeller governors. propeller control levers.

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.

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.

Which of the following is identified as the cambered or curved side of a propeller blade, corresponding to the upper surface of a wing airfoil section?. Blade back. Blade chord. Blade face.

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.

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.

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.

Cold straightening a bent aluminum propeller blade may be accomplished by. the holder of a mechanic certificate with a powerplant rating. an appropriately rated repair station or the manufacturer. a person working under the supervision of the holder of a mechanic certificate with both airframe and powerplant ratings.

Which of the following statements about constant-speed flyweight propellers is also true when referring to two-position flyweight propellers?. Blade angle changes are accomplished by the use of two forces, one hydraulic and the other centrifugal. Since an infinite number of blade angle positions are possible during flight, propeller efficiency is greatly improved. The pilot selects the RPM and the propeller changes pitch to maintain the selected RPM.

During engine operation at speeds lower than those for which the constant-speed propeller control can govern in the INCREASE RPM position, the propeller will. remain in the full HIGH PITCH position. maintain engine RPM in the normal manner until the HIGH PITCH stop is reached. remain in the full LOW PITCH position.

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.

On aircraft equipped with hydraulically operated constant-speed propellers, all ignition and magneto checking is done with the propeller in which position?. HIGH RPM. LOW RPM. High pitch range.

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.

Maximum taper contact between crankshaft and propeller hub is determined by using. bearing blue color transfer. a micrometer. a surface gauge.

Propeller aerodynamic (thrust) imbalance can be largely eliminated by. correct blade contouring and angle setting. static balancing. keeping the propeller blades within the same plane of rotation.

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.

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.

When running-up an engine and testing a newly installed hydromatic propeller, it is necessary to exercise the propeller by moving the governor control through its entire travel several times to. seat the blades fully against the low pitch stop. free the dome of any entrapped air. test the maximum RPM setting of the governor.

When lubricating a newly overhauled steel hub propeller, the aviation mechanic should lubricate the propeller. after 10 hours of operation. at the next 100-hour inspection. after one to two hours of operation.

What will happen to the propeller blade angle and the engine RPM if the tension on the propeller governor control spring (speeder spring) is increased?. Blade angle will decrease and RPM will decrease. Blade angle will increase and RPM will decrease. Blade angle will decrease and RPM will increase.

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.

What is a function of the automatic propeller synchronizing system on multiengine aircraft?. To control the tip speed of all propellers. To control engine RPM and reduce vibration. To control the power output of all engines.

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.

Propeller blade stations are measured from the. index mark on the blade shank. hub centerline. blade base.

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.

What is the purpose of an arbor used in balancing a propeller?. To support the propeller on the balance knives. To level the balance stand. To mark the propeller blades where weights are to be attached.

Which of the following occurs to cause front cone bottoming during propeller installation?. The front cone becomes bottomed in the front propeller hub cone seat before the rear propeller hub cone seat has engaged the rear cone. The front cone enters the front propeller hub cone seat at an angle causing the propeller retaining nut to appear tight when it is only partially tightened. The front cone contacts the ends of the shaft splines, preventing the front and rear cones from being tightened against the cone seats in the propeller hub.

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.

How can a steel propeller hub be tested for cracks?. By anodizing. By magnetic particle inspection. By etching.

What are the rotational speed and blade pitch angle requirements of a constant-speed propeller during takeoff?. Low speed and high-pitch angle. High speed and low-pitch angle. High speed and high-pitch angle.