Airborne liquid-spreading system

DETAILED DESCRIPTION An object of the present invention is to provide a system which spreads liquids and other flowable materials on the ground at a constant coverage level, which system compensates for the effects of the aircraft's vertical acceleration and speed over the ground.
Another object of the invention is to provide a system that may be easily adapted to perform a variety of functions, such as fighting forest fires and grass fires, seeding forests, and spreading insecticides and fertilizer on agricultural crops.
According to the invention, there is provided a system for spreading liquids and other flowable materials on the ground from an aircraft at a specified coverage level, said system comprising: a container carried by the aircraft and adapted to contain said material; means for releasing said material from the container; and means for controlling the releasing means, the control means being responsive to the difference in pressure between the material within the container adjacent to the release means and air outside the container adjacent to the release means.
Advantageously, the material is spread on the ground at a constant coverage level and the system may be easily adapted to perform any function requiring spreading a liquid or other flowable material on the ground from an aircraft.
In a preferred embodiment of the invention, the container is mounted within the fuselage of an aircraft.
Two opposed, longitudinally extending doors form the bottom of the container, and each door is attached to the container by at least one hinge.
An electrically-controlled rotary hydraulic actuator is mechanically linked to the doors and acts to move the doors about the hinges.
The rotary actuator is controlled by an electronic control system comprising a pilot interface panel, a digital controller, a level sensor, an accelerometer, and a servo card.
The pilot interface panel is used by the pilot to input the desired coverage level, aircraft speed over the ground, and volume of material to be dropped