Pratt & Whitney Rzeszów S.A.
MAINTENANCE MANUAL
PZL-10W ENGINE
73-02-00
1992.08.28
Page 16
Export Control Classification: PL/UE 9E999
The h ydr omec ha nic lim it er s act at that time as the stand-by li mit er s.
(1)
The hydromechanic limiters in the fuel metering pump.
( a )
The emergency limiter of the compressor turbine rotational speed limits the maximum compressor turbine
rotational speed (maximum observed speed) at the TAKE-OFF and 30 min. OEI ratings. After
engaging the 2.5 min. OEI rating, it shifts to the higher level.
( b )
The valve of the minimum observed rotational speed together with the switching valve do not allow the
compressor turbine rotational speed to decrease below the value necessary for the stability of
engine operation. It prevents the engine flame-out in the case of the prolonged state of the flow closing in the
bypass main by any one of the controllers.
( c)
The limitation of the maximum metered fuel capacity at the steady state ratings.
The idle jet, throttle valve and pressure drop valve act as the limiter of the maximum fuel capacity - at the
TAKE-OFF and 30 min. OEI ratings, and the G8 jet limiting the additional fuel capacity, which is delivered to
the engine combustion chamber at the 2.5 min. OEI rating.
( 2 )
The hydromechanic limiters of the power turbine rotational speed limiter.
(a)
In the AUTOMATIC OPERATION mode, the power turbine rotational speed limiter protects the power
turbine against the damage in the case of a overspeed. After the shifting, into the EMERGENCY
OPERATION mode, the limiter participates in the engine operationcontrol limiting the rotational speed of the
power turbine.
M.
The operation of the electronic limiters.
The electronic limiters in the fuel control system:
(1)
The system of the maintaining of the permanent, rated rotational speed of the power turbine.
(2)
The limiter of the rotational speed of the compressor turbine.
(3)
The limiter of the gas temperature behind compressor turbine.
(4)
The limiter of the torque at the engine output shaft.
(5)
The limiter of the minimum corrected rotational speed of the compressor turbine.
(6)
The emergency limiter of the rotational speed of the power turbine.