ATR 42 Model : 400/500
SYSTEMS OPERATING
POWER PLANT
P 4
NOV 98
001
1.16
.
30
ENGINE POWER CONTROL LAWS
TOP LAW (EEC ON)
This is a TQ (PLA) control law, ensuring a constant power.
It is backed-up by an NH (PLA) law which becomes active :
- At low power (authority of engine torque control is gradually reduced to be
cancelled out at FI),
- In case of engine torque control failure,
- In Hotel mode.
According to the rating selected on the PWR MGT rotary selector, with the PL at a
set point, the EEC commands a determined engine power and therefore a torque value
(for a given propeller speed).
Thus, the torque which is the engine control parameter, is controlled (with PLA
constant) in all ambient conditions.
AA
1
R
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