6-6-47. Securing Cargo.
The helicopter is subjected to forces which result from air
turbulence, acceleration, rough or crash landings, and
aerial maneuvers. These same forces act upon the cargo
in the helicopter and tend to shift the cargo unless it is
firmly secure. Forward motion of the helicopter is the
most rapid movement that will be encountered and is the
strongest force that is likely to act on the cargo if the
helicopter is suddenly slowed or stopped in a crash lan-
ding. Other forces tending to shift the cargo aft, laterally,
or vertically will be less severe. The amount of restraint
required to keep the cargo from moving in any direction
is called the restraint criterion and is expressed in units
of the force of gravity, or gs. In each case, the maximum
force exerted by the item of cargo to be restrained would
be its normal weight times the number of gs of the re-
straint criteria. In order to safely carry cargo, the amount
of restraint applied should equal or exceed the maximum
amount of restraint required. Restraint is referred to by
the direction in which it keeps the cargo from moving.
Forward restraint keeps the cargo from moving forward,
aft restraint keeps the cargo from moving aft, and so on.