by Jonathan M. Stern
There are numerous types of engines used on aircraft. Turbofan engines, which are found on the Lear 35, continuously burn, expand, and exhaust fuel in a rearward direction to propel the aircraft forward.
|Left Rudder||Keypad 0|
|Center Rudder||Keypad 5|
|Right Rudder||Keypad Enter|
The Cessna 182RG, on the other hand, employs a reciprocating engine. This type of engine ignites a carefully controlled fuel/air mixture in cylinders, thrusting a piston away from the head of each cylinder. This is known as a four-stroke engine.
- The first stroke is when the piston moves away from the cylinder head, drawing the fuel/air mixture through an intake valve into the cylinder.
- The second stroke is when the piston moves toward the cylinder head, compressing the fuel/air mixture in the top of the cylinder.
- The third stroke, the power stroke, is where the piston is propelled downward by the rapidly expanding ignited fuel/air mixture.
- On the fourth stroke, the piston returns toward the cylinder head pushing the exhaust gases out through the exhaust valve.
The movement of the pistons is transferred through connecting rods to a crankshaft, and ultimately to a propeller. Although some general aviation airplanes have fuel-injected engines, the Cessna 182RG uses a carbureted, 235 horsepower, six-cylinder, Avco Lycoming engine—the O-540-J3C5D.
The engine in the Cessna 182RG is operated with four controls. A fuel selector valve on the floor board of the airplane controls the flow of fuel to the carburetor. The fuel selector valve is controlled from the Sim/Engine and Fuel menu and may be set to off, left tank, right tank, or both tanks (all).
A throttle control and mixture control are mounted on the airplane's instrument panel. The throttle controls the quantity of fuel/air mixture entering the engine and may be manipulated by dragging them with the mouse or in accordance with the keystrokes in the following table:
|Control||Keyboard (F keys on top)||Keyboard (F keys left side)|
|Throttle Increase*||Keypad 9 or F3||Keypad 9 or F6|
|Throttle Decrease*||Keypad 3 or F2||Keypad 3 or F8|
|Throttle Full Open||F4||F4|
The mixture control adjusts the ratio of fuel to air that enters the engine. The mixture is adjusted with reference to an exhaust gas temperature gauge, which is mounted on the instrument panel. As the airplane gains altitude, the mixture must be leaned to adjust for the decreasing density of the air with which the fuel is being mixed. During the descent, likewise, the mixture must be enriched. For simplicity in initial Flight Simulator flight training, the mixture control is not selected and will not be used. You will learn the proper use of the mixture control when you transition to a high performance airplane.
The fourth engine control is the ignition switch. Ignition is provided through a system of dual magnetos, each of which is connected to one spark plug in each cylinder.
Magnetos are self-contained, engine-driven units that provide electrical current without an external source of current. The purpose of the dual magneto system is to keep the engine running in the event that one of the magnetos fails. The magnetos may be controlled with the ignition switch, by setting to L or R, so that only the left or the right magneto is firing. These settings test the magnetos during the pre-flight engine runup. The ignition switch has settings for off, left, right, both, and start, which engages a battery-powered starter. The ignition switch may be controlled by clicking each setting with the mouse, from the Sim/Engine and Fuel menu, or by pressing M followed by the plus or minus key.