1. Engine operating condition
Unit I
Engine operating condition

2. Starting reciprocating engines
The starting of engine can be relatively simple matter or it can be a very complex and critical operation depending upon the size and type of the Engine.
No attempt should be made to use the methods presented here for actually starting the engine.

3. Engine starting precautions
The aircraft should acquire the following safety habits.
Treat all the propellers as though the ignition switches were on.
Chock airplane or test stand wheels before working around the engine.
After an engine run and before the engine is shut down ,perform an ignition switch test to detect a faulty ignition circuit.

4. Before the moving a propeller or connecting an external power source to an aircraft be sure that the aircraft is chocked, the ignition switch is off position , throttle is closed , the mixture is in idle cutoff position.
Ground clearance
Only authorized person can start the engine.
Safety measures are taken into account.

5. Ground engine fire
If an engine fires occurs while engine is started move the fuel shutoff lever to off position.
Co2 can be discharged into the inlet duct .
Do not discharge co2 directly into the engine exhaust because it may damage the engine.
If the fire is on ground under the engine overboard drain, discharge the Co2 on the ground rather than on the engine

6. Starting prodeures for float carbuertors
Set the master switch to on.
Turn on the boost pump if needed.
Open the throttle approximately ½ in(1.27 cm)
If the engine is equipped with a constant speed propeller , the propeller control should be set in full increase position
Set the carburetor heat lever to cold off position

7. Set the mixture lever in full rich position
Clear the propeller
Turn the ignition switch to start position.(mostly it allows magnetos to be energized).
Release the ignition switch.
Check for oil pressure.

8. Bendix fuel injection starting procedure
It is designed to avoid flooding the engine and to provide positive results .
Put the mixture in the idle cutoff position
Adjust the throttle to 1/8 in (3.1mm) open.
Turn off the master switch.
Turn on the booster pump switch.
Clear the propeller.
Turn on the ignition switch to start position.

9. As soon as the engine starts move the mixture control to full rich.
Release the ignition switch.
Check for oil pressure.

10. Continental continuous flow fuel injection starting procedures.
Turn the ignition switches to on.
Open the throttle approximately 1/2in (1.27).
Set the propellor pitch lever full forward to high rpm.
Set the mixture lever full forward to full rich
Clear the propeller.
Turn the ignition switch as soon as the engine fires.

11. Turn off the auxiliary fuel pump switch when the engine run smoothly.
Check for an oil pressure indication with in 30s is normal in cold weather and 60 s is in cold weather.
Disconnect the external power source , if used.
Warm up the engine at 800 to 100 rpm.

12. Starting large reciprogationg engines
As per manufactures instructions

13. Hand cranking
Carried out with low battery or defective starter.
Onle experienced persons should do the hand cranking and a reliable person should be in cockpit.
If the aircraft has no self starter the engine must be started by swinging the propeller ..
The person who is turning the propellor calls out “fuel on ,switch off ,throttle closed ,brakes on”.

14. Cruise control
It is the adjustment of engine controls to obtain the results desired in range ,economy or flight time .
Since the aircraft consumes more fuel at high power settings than at lower settings, obviously maximum speed and maximum range or economy cannot be attained with in the same power settings.

15. Range and speed chart

17. Engine operating conditions
Leaning the mixture
With the mixture full rich position a predetermined mixture of fuel and air is used .
For takeoff a mixture is setting of full rich is used.
This setting ensures the best combination of power and cooling.

18. As an aircraft climbs the air becomes dense .
On full rich setting the carburetor is putting out the same amount of fuel, but there is less air to mix with it, so the mixture gets richer .
If the aircraft climbs high enough the F/A ratio becomes too great for smooth operation.not only the engine run roughly ,but also fuel will be wasted.
Two types of fuel metering float carburetor and fuel injection.

19. Problems caused by spark plug lead fouling
Many aircraft engines designed to operate on 80/87 –octane avgas are forced to use 100ll (low lead) avgas because of the reduction in the availability of 80/87 avgas.
Although the engines are approved to operate on 100ll avgas ,this presents the problems of spark plug fouling because 100ll avgas contains four times of TEL(tetraethyl Lead) .
This sparkplug fouling leads many operational problems and can increase the need for spark plug cleaning.

20. Reciprocating engine operations in winter
Winterization procedures-(precautions and preparations )
Draining sumps-(important during changes in temperature, particularly near freezing )
Anti-icing additives-anti-icing agents ISOPROPYL ALCHOLOL or EGME
Engine preheating

21. ENGINE PREHEATING PRECAUTIONS
Preheat the aircraft by storing in a heat hanger, if possible.
Use only heater that are in good conditionand do not refuel the heater while it is operating
During the heating process, do not leave the aircraft unattended and keep a fire extinguisher handy.