Figure 3-13. Pesticide dispersal unit.
b. Capabilities and Features. The remote control operates the PDU from
inside the helicopter. When the system switch is in the on position, battery power is
applied to the engine. With the system switch on and the engine start switch in the start
position, the engine will begin to drive the hydraulic pump and pressurize the system.
Pressing the dispersal push-button will release the pesticide. The PDU has a tail fin for
stability during flight and is attached to the helicopter with a six- foot nylon strap. A
quick-disconnect connection for the remote control protects the operator if the PDU
must be released from the helicopter in an emergency. The PDU can be used without
modification on any helicopter with a cargo hook.
c. Major Components. The PDU consists of the following major components.
(1) Hopper assembly -- fiberglass hopper that holds granular or liquid
pesticides. Support frame provides for mounting for engine, gas tank assembly, pump,
and hydraulic reservoir.