Page 11 - IFR_Book_Sample-2020

IFR-Chapter-3-V8_IFR-Chapter-3.qxd 12/19/2019 4:18 PM Page 12

3-12 Rod Machado’s Instrument Pilot’s Handbook
Now it’s time to nudge your noodle a bit. Suppose we attitude indicator and vertical speed indicator become the
wanted to change airspeed while we were in level flight supporting pitch instruments (as we’ve previously shown
or in a turn. Which instruments are primary and support- in Figure 18).
ing in these two conditions? Here’s another example. Suppose you’re transitioning
The primary and supporting pitch and bank instru- from straight and level flight into a level, standard rate
ments don’t change for either of these conditions, but the turn at a specific airspeed. You’ll enter the turn using the
power instruments do (Figure 20). When changing air- attitude indicator, so you’ll start your scan there. During
speed, the RPM/MP gauge becomes temporarily signifi- the transition, as you’re rolling into the turn, the attitude
cant, thus it becomes primary, with the airspeed indicator indicator is primary for bank, the altimeter is primary for
a supporting instrument. After all, we may look at the pitch, and the airspeed indicator is primary for power as
RPM/MP gauge as we set the power value (Figure 20, shown in Figure 22. The turn coordinator is supporting
position A) used to give us the target airspeed (approach for bank, the attitude indicator and vertical speed indica-
airspeed, for instance). Once the desired airspeed is tor are supporting for pitch, and the RPM/MP is support-
reached, the airspeed indicator becomes primary for ing for power. Once the turn is established, the primary
power and the RPM/MP gauge becomes a supporting and supporting instruments are the same as those previ-
power instrument (Figure 20, position B). As a general ously shown in Figure 17.
rule, any time the throttle is being moved to a specific set- Of course, there are many subtleties that we’ll cover
ting, the RPM/MP gauge becomes the primary power regarding what to do in correcting for small altitude and
instrument. heading variations. These aren’t too important right now.
I’m more interested in putting your knowledge of primary
and supporting instruments to work in that three-step
scan procedure I talked about earlier. We’ve put in a lot of
effort figuring out how to decide which instruments are
primary and secondary. Besides the fact that it’s on the
FAA knowledge exam, why do you care? Because this
information is going to determine how you scan the
instruments at any moment, and scanning the instru-
ments is the core skill of instrument flying.
Instrument Scanning: Doing the Three-Step
All knowledge begins with definition. No, I didn’t make
that up. It sounds too good. Besides, it’s true. Before I can
show you how to scan instruments, I want to be sure you
understand what I mean by the term instrument scan.
When I speak of instrument scan, I’m talking about
how you will check the primary and supporting instru-
Fig. 20 ments, interpret them, then use them to ensure that the
airplane is being controlled properly. All of this can be
What we haven’t talked about yet is transitioning
between different attitudes. This is where the attitude packaged into a three-step scan procedure that you’ll use
every time you make a major attitude change. These
indicator plays a very big part in attitude instrument fly-
three-steps will now be officially called our instrument
ing. As a general rule, whenever you’re transitioning
scan procedure.
between attitudes (i.e., making a major attitude change),
the attitude indicator becomes primary for either pitch
and/or bank during the transition. This is why the word
START is found under the attitude indicator. All major
attitude changes should start with a look at this instru-
ment. Major attitude changes include rolling into or out of
a turn, pitching up or down to climb or descend, or any
combination of these. All these attitude changes are ini-
tially made by focusing on the attitude indicator until the
transition is complete. This is a very important point for
you to understand.
For instance, if you’re transitioning from straight and
level flight to a constant-airspeed climb, the attitude indi-
cator is the primary pitch instrument during the transi-
tion. The airspeed indicator and vertical speed indicator
become the supporting pitch instruments as shown in
Figure 21. Once you’re established in the correct attitude, Fig. 21
the airspeed indicator becomes primary for pitch and the