Peculiarities of the forest firefighting with the use of aircrafts

The use of aircrafts improves the efficiency of forest fires suppression. Currently, the most widely used aircrafts are GL-215 Canadair, BE-200, and Il-76. The corresponding maps and irrigation density of the extinguishing agents have been experimentally obtained for them.
The density and size of irrigation maps is significantly affected by the aircraft flight altitude. The height of the extinguishing agent discharge is determined by the safety of the flight over the fire zone, which in turn introduces significant aerodynamic disturbances into the atmosphere.
The irrigation density is influenced by dispersion and viscosity of the extinguishing agent as well as the meteorological conditions, primarily the direction and speed of wind.
In this regard, it is important to obtain the formulas for calculating optimum flight altitude, extension of zones, and irrigation density. These formulas include the parameters that take into account the characteristics of both aircraft (the speed) and drain devices (the sizes and fire flow). Investigation of the efficiency of the use of aircrafts in forest firefighting is time-consuming and expensive. It is proposed to test the water additives using a special experimental setup simulating both the dispersion of the fire extinguishing agent discharged from the aircraft and the crown and ground forest fires. The fires are simulated by specific heat release, and the dispersion, by specially selected sprinklers.
Fire experiments have shown a significant impact of the viscosity of fire extinguishing agents on the forest fire suppression. It is required to optimize viscosity by means of water additives.