One of those old nagging questions from a non-pilot. What is the diff between rpm and throttle in this game? Every time Im asked to adjust manifold pres in a 17 I adjust throttle. Am I doing this wrong?
Throttle is identical to the gas pedal on your car, when you press it a butter fly valve opens and lets more air into the engine, creating more power. Unlike a car a plane has a gauge that measures the pressure inside the intake manifold. This is called the Manifold pressure gauge. In American planes it is measured in Inches of mercury just like a barometer. If the plane does not have a super/tubo charger the max manifold pressure will be slightly less the the current barometric pressure.
In a car your rpm is tied to the wheel speed via transmission. So when you change gear you can have the same gas pedal position and power but different RPMs.
A plane basically has an infinite number of gears by changing the pitch of the propeller. It has a fly ball governor that in most planes feeds oil to the prop to control its pitch (More when to fast less when to slow) and hence maintains a constant RPM. Your rpm control set the desired RPM for the governor to maintain. So in a sense the RPM control is very much like a gear shift lever.
HiTech
