12.24. Engine Management - Piston

12.24.14. State the possible causes of a sudden engine failure in flight, and the remedies which may be available to a pilot during subsequent trouble checks. 

– Fuel related. Either running out of fuel, fuel pump failure, or incorrect mixture setting.
– Ignition related,
– Catastrophic failure of engine components.
– Carburettor iceintake ice
Possible remedies:
– Carb heat to hot immediately. (Or alternate air if applicable)
– Fuel –
– Change tanks
– Auxiluary fuel pump on
– Mixture rich (try through range)
– ignition-
-cycle ignition switch to see if one or other system works/ possible faulty connection.
– move throttle through full range. As well as checking for partial power this may dislodge carb ice around the butterfly.

12.24.12. State the actions that the pilot may take to identify and rectify rough running or excessive engine vibration. 

see previous (12.24.10) for action re carb ice or incorrect mixture.

12.24.10. State the possible causes for rough running or excessive engine vibration.

Incorrect Mixture
– depends how badly out of kilter the mixture is
– if over-rich on levelling out from a climb to altitude carry out recommended leaning procedure
– if over lean on a descent from altitude, put mixture to full rich and then lean as recommended if appropriate.
– carb ice can also cause rough running, particularly while ice is melting and being ingested by the engine.
Carburettor Ice
– gradual loss of rpm = formation of carburettor ice
– if in conditions favouring carburettor ice then apply full carburettor heat
– if the symtpoms disappear set carburettor heat to OFF

Faulty Ignition
– rough running occurs suddenly / intermittently
– if flying with low power setting – try flight at increased speed
otherwise try reducing power to a low cruise setting and switch ignition switch carefully to each of L and R magnetos
– if running on one of the systems only then prepeare to land asap

12.24.8. Explain the need for monitoring and cross-checking engine instrument indications.

Engine Instrument Indications / Checking
– monitor gauges which indicate overheating
– oil temperature gauge and cylinder head temperture (CAT) if fitted
– trends shown by gauges can indicate potential problems before they become serious. eg reducing oil pressure and rising oil temperature can be a warning of an oil leak or a shortage of oil.

12.24.6. Explain the reasons for avoidance of rapid power changes.

Rapid Power Changes
– the throttle should be opened and closed smoothy and steadily
– rapid opening and closing can increases mechanical and thermal shock and stress to moving parts
– engine can cut out due to a mismatch between mixture and rpm

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)