CPL Acft Tech - Propellers

A disadvantage of a fixed pitch propeller is...

• it has only one speed at which it reaches maximum efficiency

• it has only one altitude at which it reaches maximum efficiency

• it has only one temperature at which it reaches maximum efficiency

• it has only one air density at which it reaches maximum efficiency

You are flying an aircraft fitted with a Constant Speed Unit (CSU). The aircraft is in the cruise at 8,500 feet and a TAS of 150 knots. What will the CSU do if you were to lower the nose of the aircraft without touching any other controls?

• increase the propeller blade angle

• reduce the propeller blade angle

• place the propeller into reverse thrust

• It would not do anything

When you want to increase the speed of an aircraft fitted with a CSU, the correct method is to;

• select a rich mixture, select a finer pitch, increase the throttle

• select a rich mixture, select a coaser pitch, increase the throttle

• increase the throttle, select a rich mixture, select a finer pitch

• select a coarser pitch, increase the throttle, select a rich mixture

Consider an aircraft fitted with a Constant Speed Unit (CSU). At a given RPM setting, if the throttle is advanced (increased), what will happen?

• propeller RPM will decrease

• propeller RPM will increase

• engine torque will increase

• propeller torque will decrease

If power is applied whilst a propeller is being moved from fine pitch to the reverse thrust angle, what is likely to result?

• Normal operation of the propeller in reverse thrust

• A propeller overspeed

• Engine torque will be negated by propeller torque

• A critical engine

Select all of the following actions that are likely to assist if you suffer a Constant Speed Unit (CSU) failure while flying an aircraft in the cruise, causing the propeller to begin overspeeding.

• Reduce the throttle

• Lower the nose of the aircraft

• Put the pitch control into full coarse

• Enter a steep turn

When you want to decrease the speed of an aircraft fitted with a CSU, the correct method is to;

• adjust the mixture, adjust the pitch, reduce the throttle

• select a rich mixture, adjust the pitch, reduce the throttle

• reduce the throttle, adjust the pitch, adjust the mixture

• adjust the pitch, reduce the throttle, select a rich mixture

When flying an aircraft fitted with a constant speed unit, what controls the manifold pressure?

• throttle

• mixture

• pitch lever

• carburetor heat

Select all of the correct options...

A typical Constant Speed Unit (CSU) governor incorporates...

• flyweights

• oil

• a speeder spring

• barometric sensing

If a Constant Speed Unit (CSU) fails it can immediately cause...

• the engine to seize

• the engine to stop, due to the increased propeller torque

• the propeller to become detached from the aircraft

• the propeller blade angle travelling to full coarse