TM 55-1500-342-23
c.
Reduce rate of climb.
d.
Reduce cruising speed.
e.
Increase stalling speed.
f.
Reduce maneuverability.
g.
Reduce ceiling.
h.
Reduce range.
i.
Increase landing distances.
j.
Instability.
2-4. Floor Loading. Floor loading is the weight of a
load ill pounds divided by the area of floor space which
the load occupies. [For example. the floor loading for a
100-pound container is determined as follows:
Base of container = 20 in x 20 in = 400 sq in
Floor loading = 100 lb = 0.2 lb per sq in
400 sq in
or 0.25 lb sq in x 144 = 36 Ib/sq ft.
Floor loading limits or a plan view of the cargo floor
showing
variations
in
floor
strength
and
weight
concentration limitations for various compartments are
specified in the applicable -10 operator's manual.
2-5. Ballast. Ballast is some form of weight placed in a
specific location in an aircraft to insure stability of flight
by compensating for unfavorable weight and balance
conditions. Two types of ballast are permanent ballast
and temporary ballast.
a.
Permanent Ballast. In certain instances
modification work orders will call for the removal or
addition of equipment which will have a marked effect
on aircraft weight and balance conditions When this is
the case, it is necessary to install ballast weights to
maintain the center of gravity position within the center
of gravity limits. The agency responsible for preparing
the modification work order will consider effects of the
modification on weight and balance conditions and will
specify requirements for installation of permanent
ballast weights when required. Maintenance activities
that install permanent ballast weights are responsible for
making the proper entries on DD Form 365-1, Basic
Weight Check List. and DD Form 363-3. Basic Weight
and Balance Record.
b.
Temporary Ballast. Temporary ballast consists
of such weights as may be necessary to compensate for
missing crewmembers, weapons systems, ammunition,
and equipment in order to maintain center of gravity
positions within the center of gravity limits. Shot bags or
other similar items may be used for temporary ballast
provided they are properly secured. The amount and
location of temporary ballast required to maintain safe
flight will be determined by the pilot or weight and
balance technician.
Section II. BALANCE
2-6. General. The purpose of this section is to outline
the method for determining the cg position of a loaded
aircraft. Although location of the cg is very important to
safety of flight. it can be easily controlled by proper
loading of the aircraft. Balance. or the location of the
aircraft center of gravity. is of primary importance to
aircraft stability. A pilot should never fly an aircraft if he
is not personally satisfied with its loading and balance
condition. The center of gravity (cg) is the point about
which an aircraft would balance if it were possible to
support the aircraft at that point. It is the mass center of
the aircraft. or the theoretical point at which the entire
weight of an aircraft is assumed to be concentrated.
a.
The prime concern of balancing is longitudinal
balance. or the location of the cg along the
longitudinal axis. Location of the cg with reference to
the lateral axis. however. is also important. The design
of an aircraft is such that symmetry' is assumed to exist
about a vertical plane through the longitudinal axis. In
other words. for each item of weight existing to the left
of the fuselage centerline there is generally an equal
weight existing at a corresponding location on the right.
This lateral mass symmetry. however. may be easily
upset due to unbalanced lateral loading. Location of the
lateral cg is not only important from the aspect of
loading rotary wing aircraft. but is also extremely
important when considering fixed wing exterior drop
loads. The position of the lateral cg is not computed.
but the operating crew must be aware that adverse
effects will certainly arise as a result of a laterally
unbalanced condition.
2-2
