
Pratt & Whitney Rzeszów S.A.
MAINTENANCE MANUAL
PZL-10W ENGINE
71-02-00
1992.08.28
Page 520
Export Control Classification: PL/UE 9E999
NOTE:
At ambient temperature 278 K ( + 5°C; 41 °F) and lower, switch on air bleeds for
the engine icing protection system and cabine heating system.
When the engine started, switch-off unnecessary air bleeds.
(e)
Press the START push button for 2 ÷3s, the starting box light "START ON" shall switch on;
(f)
Check, if the gas temperature increases correctly and the engine goes automatically to the
Gl rating.
K.
Engine operation.
(1)
General.
When started, the engines operate at GROUND IDLE (Gl) rating. This is the initial range to warm
up the oil in the engines and main gearbox and to check parameters as per para 4.
Then, by shifting the operation control lever to the AUTOMATIC OPERATION position, the engine
goes to the FLIGHT IDLE (Fl) rating.
Engine power at ratings higher then Fl - up to TAKE OFF rating included, as well as at both OEI
ratings with higher parameters than that at TAKE OFF is automatically controlled in relation to the
adjustment of the collective pitch lever of main rotor (main rotor loading). Electronic limiter unit
provides automatic control of engine power, furthermore synchronizes the torques of both engines,
prevents exceeding limits of basic parameters and controls the compressor bleed air valve and
engine start system.
If any automatic control path is damaged, switching to manual engine control is possible. Then
engine operation parameters shall be limited manually using the engine control lever and collective
pitch lever of main rotor.
At this condition, the speed governor servovalves protect the engine against exceeding the
specified speed limits of turbocompressor and power turbine rotors.
In case one of twin engines fails to operate, the second engine goes automatically to the increased
power mode (OEI 30 min. rating), and electronic limiter unit maintains appropriately higher limits of
standard operation parameters at this range. It is also possible to switch to the highest engine
power rating (OEI 2.5 min.) after switching on proper push button. It causes switching of the fuel-
control system to the highest limitation level of the basic engine operation parameters.