POWER PLANT Flashcards
ENGINE SYSTEM
Aircraft fitted with
– two Pratt &Whitney, PW 127M
– two, six blades propellers (Hamilton)
It is a free turbines engine, composed of 3 concentric shafts of spools:
– The shaft of the HP spool composed of the HP turbine and the HP compressor (rotation speed of the HP spool: NH). The HP spool drives the accessory gear box (AGB)
– The shaft of the LP spool composed of the LP turbine and the LP compressor (rotation speed of the LP spool: NL)
– The Power shaft composed of 2 power turbines (Free turbines). This 2 power turbines drive the propeller through the reduction gear box (RGB) (rotation speed of the propeller NP)
REDUCTION GEAR BOX
REDUCTION GEAR BOX
These equipments are fitted on the RGB
– the ACW generator
– the Propeller Valve Module (PVM)
– the propeller pump (HP) and overspeed governor
– the auxiliary feathering pump
– the propeller brake (on RH engine only)
ACCESSORY GEAR BOX
ACCESSORY GEAR BOX driven by the HP spool. Drives – the DC starter/generator – the HP fuel pump – the engine oil pumps
Power formula
Power (PWR) = Torque (TQ) x NP
For the same power:
If TQ increases, NP decreases
If TQ decreases, NP increases
Power setting is characterized by constant power lever (PL) and condition lever (CL) positions. The power adapted to the flight phase is selected by the pilot through a power management selector (PWR MGT).
– With input coming from the PWR MGT and the position of the PL, the EEC (Engine Electronic Control) control the fuel flow to the engine.
