User Guide

Learning To Fly with Rod Machado
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Tutorial 12: Trimming Using the VSI and
Monitor Scanning the Big 6 Instruments
(Step Three of the Three-Step Instrument Scan)
By now, you know that instrument pilots are not folks who sit in airplanes and play piccolos or
guitars. The closest they come to making music occurs as they follow a step-by-step instrument scan
procedure when making a major attitude change. So far, we’ve covered two of the three steps. Let’s
complete our instrument scan procedure by studying the last step in the three-step scan.
Here are the three steps for your review. They’re listed in the order you’d do them when making a
major attitude change.
Step 1: Select attitude, power, and trim.
Step 2: Radial scan the primary instruments.
Step 3: Trim using the VSI and monitor scan the Big 6 instruments.
In Step one you made a major attitude change. In Step two, you fine-tuned the airplane’s pitch, bank,
and power. In Step three, you’ll offer a final twist of the trim so the airplane stays put, then you’ll relax
a bit and monitor scan the six main flight instruments on your panel (also known as the Big 6
instruments). Monitor scanning is a more relaxed way of observing the flight instruments compared
to the radial scan of Step two. Let’s take a closer look at Step three of the scan.
Trimming with the VSI
Your main objective in Step three is to make a final trim adjustment by referencing the vertical speed
indicator (VSI). The VSI is very sensitive to small pitch changes and will quickly indicate any deviation
away from the desired attitude. Additionally, the length of the VSI’s needle makes it easy to detect
vertical movement.
The secret of the final trim is to look for a constant VSI indication. When leveling off, trim so that the
VSI needle indicates a zero rate of climb. Since you may be using keyboard buttons to trim, make
sure you don’t sound like you’re a telegraph operator. Give the trim wheel a slight twist (or the button
a push) and then ease up on any control pressures you might be applying. Watch the VSI’s needle. If
it moves up or down, apply nose-down (7 on your keyboard’s numeric keypad) or nose-up (1 on your
keyboard’s numeric keypad) trim to stop the needle’s movement. (Remember that NUM LOCK has to
be off.)
Trimming for a climb or descent is done in a way similar to trimming for level flight. Relax control
pressure and watch for a constant VSI needle indication. Suppose the needle indicates a specific