Figure 5-1. Pitch Attitude and Airspeed in Level Flight, Slow Cruise Speed

Straight-and-Level Flight

Pitch Control
The pitch attitude of an airplane is the angle between the
longitudinal axis of the airplane and the actual horizon. In
level flight, the pitch attitude varies with airspeed and load.
For training purposes, the latter factor can normally be
disregarded in small airplanes. At a constant airspeed, there is
only one specific pitch attitude for level flight. At slow cruise
speeds, the level flight attitude is nose high with indications
as in [Figure 5-1] at fast cruise speeds, the level-flight attitude
is nose low. [Figure 5-2] Figure 5-3 shows the indications
for the attitude at normal cruise speeds. The instruments used
to determine the pitch attitude of the aircraft are the attitude
indicator, the altimeter, the vertical speed indicator (VSI),
and the airspeed indicator (ASI).

Attitude Indicator
The attitude indicator gives the direct indication of pitch
attitude. The desired pitch attitude. is gained by using the
elevator control to raise or lower the miniature aircraft in
relation to the horizon bar. This corresponds to the way pitch
attitude is adjusted in visual flight by raising or lowering
the nose of the airplane in relation to the natural horizon.
However, unless the airspeed is constant, and until the
level flight attitude for that airspeed has been identified and
established, there is no way to know whether level flight as
indicated on the attitude indicator is resulting in level flight
as shown on the altimeter, VSI, and ASI if the miniature
aircraft of the attitude indicator is properly adjusted on the
ground before takeoff; it shows approximately level flight at
normal cruise speed when the pilot completes the level off
from a climb. If further adjustment of the miniature aircraft
is necessary; the other pitch instruments must he used to
maintain level flight while the adjustment is made.

Figure 5-2. Pitch Attitude and Airspeed in Level Flight, Fast Cruise Speed.

Figure 5-3, Pitch Attitude and Airspeed in Level Flight, Normal
Cruise Speed.