User Guide

Learning To Fly with Rod Machado

Trust Your Thrust

In Tutorial 2, we mentioned that thrust (produced

by the engine-propeller combination) is the force

that moves the plane forward. The engine’s

manifold pressure gauge is your means of

measuring that thrust. Figure 2 shows the manifold

pressure gauge, which is located at the lower left

side of the instrument panel (don’t get it confused

with the fuel flow gauge on the right).

Think of the manifold pressure gauge as the engine’s power meter. Applying full throttle gives you

more manifold pressure, which means the engine’s producing more power (thrust). Reducing the

power to idle gives you less manifold pressure, which means the engine’s producing less power

(thrust).

Look carefully at the calibrations on the manifold pressure gauge. They range from a low of 10 inches

to a high of 35 inches. Inches? Huh? Don’t worry. This is just another means of calibration (it’s like

using liters instead of quarts). For now, just use the calibrations on this gauge to adjust your throttle.

If I say “set the manifold pressure (MP) to 22 inches,” then move the throttle until the needle on the

MP gauge points to a value of 22. (That’s two tiny increments above a reading of 20 on the MP

gauge. If you can’t read those increments, don’t worry. Just use a ballpark estimate.) If I say give me

full power, then move the throttle all the way forward and don’t worry about the MP reading. A

request to reduce the power to flight idle means to pull the throttle all the way back and, once again,

don’t worry about the MP reading. Easy enough, right?

Now look in the upper left corner of the six main flight instruments, and you’ll find the airspeed

indicator (Figure 3). The airspeed indicator shows

the speed of the wind blowing on your airplane

(which is not necessarily the same thing as how

fast your airplane is moving). It’s calibrated to read

in knots (or nautical miles per hour) and has

nothing to do with what’s going on in a pilot’s

stomach. You’re presently flying at an indicated

airspeed of 110 knots.

Figure 3

Figure 2

MP GAUGE

AIRSPEED

INDICATOR