TM 55-1500-342-23
Figure 2-2. Locating Aircraft Center of Gravity
2-11. Effects of Unbalanced Loading. When the
aircraft is nose heavy (cg too far forward), the pilot will
experience difficulty in getting the tail down during
landing. Other unfavorable conditions which may result
are loss of aircraft maneuverability, overstress of the
nose wheel structure in landing, and increase in pilot
fatigue. When a tailheavy condition exists (cg too far
aft), the aircraft may become unstable. This condition
increases pilot fatigue, and may lead to structural failure
and spins.
2-12. Determining Center of Gravity for a Group of
Items. It is sometimes desirable to find the average
arm or cg for a group of objects in an aircraft. This is
accomplished by finding the individual moment of each
object in the group, adding these moments, and dividing
this sum by the total weight of all the objects in the
group. It is expressed by the formula:
Average arm (in) = total moment (in lb)
Total weight (lb)
It should be noted that the basic aircraft weight and
moment are excluded from this calculation.
2-13. Center of Gravity Limits. After the cg position
of a loaded aircraft has been calculated, it is necessary
to insure that the cg falls within allowable limits. All
aircraft have specific limits between which the cg must
lie. These limits are specified in Chart E data covering
the particular aircraft. If, after loading the aircraft, the
cg does not fall within the allowable limits, it will be
necessary to shift loads.
a.
The forward cg limit may vary with the gross
weight of an aircraft and is often restricted to control
landing conditions. It may be possible for aircraft to
maintain stable and safe flight with the cg
2-5
