Air Combat Maneuvering
Background
THE EGG
Figure 4 depicts “the egg,” representing a three-dimensional sphere showing the effects of gravity as
you maneuver in all planes. You already know, or at least have been introduced to, all the concepts
and principles we are about to discuss. However, outflying the bandit depends on what you know
about your airplane, the arena, and the bandit. Let’s first take a look at turn performance.
Horizontal Maneuvering
The most basic of all aerodynamic principles states that an aircraft, to maintain straight-and-level
flight, must generate exactly 1 g to overcome the effects of gravity. Because the amount of lift
required to maintain 1-g flight is based on the weight of the aircraft (excluding the effects of drag),
the vector representing gravity remains constant as long as the weight of the aircraft remains
constant.
An aircraft in a turn at any angle of bank must generate additional load factor in order to meet the
same effective lift. The load factor increases because your lift vector is moved out of the pure
vertical. If we assume that the effective lift of the aircraft opposes gravity (which is a constant force),
the load factor will vary according to how tightly you want to turn the aircraft. As you can see in
Figure 2 , both aircraft a and b are in level turns at a constant true airspeed (TAS). Aircraft a is in an
80-degree AOB and aircraft b is in a 60-degree AOB. Because aircraft a is turning at an 80-degree
AOB, his load factor is greater than aircraft b turning at a 60-degree AOB. Notice that because
gravity and the effective lift remain constant forces, the resultant vector, referred to as “radial g,”
actually turns the aircraft. Radial g is the horizontal component of lift. If you pull harder in a turn,
which is indicated on your accelerometer and referred to as “indicated g,” you are increasing the load
factor. Depending on your situation (your snapshot in time), this triangle will change. Simply put, the
larger the radial-g vector, the better the turn performance. As you see in Figure 2, in a purely
horizontal turn, the greater the AOB, the greater the load factor to maintain effective lift. This greater
load factor produces greater induced drag, resulting in a higher energy loss. As you will see, you will
want to avoid the pure horizontal because of this.
RGb
RGa
EFFECTIVE
EL
EL
LIFT FOR
LFb
LFa
BOTH PLANES
80 AOB
60 AOB
G
G
GRAVITY
LF=LOAD FACTOR
G=GRAVITY
Aircraft a
Aircraft b
RG=RADIAL G
EL=EFFECTIVE LIFT
Figure 2: HORIZONTAL MANEUVERING
(10-98) Original
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