12.24.4(f) . stopping the engine.
– brief run down of engine at 1000 rpm before stopping to allow temps to stabilise
– check for dead cut (mags off then back on)
– place the mixture control into IDLE CUT-OFF
– close throttle as rpm dies down
– after engine stops move ignition switch and other switches to OFF
12.24.4(e) . checking oil pressure after start;
– After starting an engine it is essential to check that oil pressure rises within a reasonable time. The typical situation is to expect the oil pressure gauge to show an increase in oil pressure within 30seconds. (or time stated in aircraft flight manual) . If oil pressure does not rise within the time then shut the motor down.
12.24.4(d) . controlling an engine fire on start-up;
If fire is in engine air intake during start-up
– continue cranking the engine with the starter to move air through
– move the mixture control to IDLE CUT-OFF – to remove source of fuel
– open throttle – maximises airflow to carburettor and purges it of fuel
If fire doesn;t go out
– Fuel – OFF
– Switches – OFF
– Evacuate with extinguisher
– If necessary/possible use extinguisher.
12.24.4(c) . starting a hot engine;
Hot Engine Start
– should start satisfactorily using the norjmal procedure with reduced or no priming
– failure to start at first attempt maybe due to over-priming or flooding of the carburettor
– if fuel injected boost pump can be used to counter vapour lock (See AFM)
12.24.4(b) . starting an over-primed engine;
Over Primed engine
– turn the engine over through a few revolutions using the starter motor with the mixture control to IDLE CUT-OFF and throttle fully open.
– then select FULL RICH position close the throttle then “crack” it open to the normal starting position and try starting again but without priming
– if the engine fires during the clearing procedure immediately put mixture to FULL RICH and retard the throttle to normal starting position
12.24.4(a) . staring the engine in cold temperatures;
Cold engine / cold air
– requires maximum amount of priming
– in really cold conditions it can help to turn the primed engine over by hand (magnetos off) 2-3 revolutions to free it up and draw mixture into the cylinders. ( follow hand starting procedures)
12.24.4. In general terms, explain the procedures for:
12.24.2. State the safety precautions to be taken before starting the engine.
Area
– operational area of airfield with restricted access to public
– position aircraft facing into wind
– clear hardstanding area or firm grass area
– no loose objects or material which may cause damage if caught in slipstream
– areas to the front and rear should be cleared
Brakes
– park brake should be ON
– or chocks in place ahead of the main wheels
Fire Extinguisher
– awareness of the position of the nearest fire fighting equipment in case of fire at start up
Propellor Awareness
– make sure area is clear / warn bystanders re engine start up
– if someone in danger zone move mixture to idle cut-off
12.22. Ignition systems Solid State
12.22.8. Describe the operation and correct handling of ignition/starter switch systems.Sub Topic Syllabus Item
– Starter motor system draw large electrical currents and therefore create significant heat. For this reason there should be a rest between bursts of use and long duration engagement or continuous use of the starter is not recommended.