Dimensioning of an hydraulic system

for water bombing from an aircraft




The goal of this BEI is to provide a study on water bombing by transport plane for aerial firefighting. Airbus Military is willing to adapt its transport planes such as CASA (which are currently used for transport of goods, men, ...) to drop water or retardant on a fire.


Industrial Environment

The air fleet of the "Securité Civile Française" ( French Civil Security Policy), based at Marignane in France, has a complete system for firefighting in forests. The air fleet consists in 26 aircrafts, among them 23 bombers (11 Canadair CL 41, 10 Trackers, 2 Dash) and 3 aircrafts Beechcraft. 

Canadair CL 425

Dash 8 Q 400 MR


Source :

Nowadays, we have to replace the fleet which is ageing, in particular regarding the Trackers. This market is an important stake for Airbus, which is willing to create an aircraft for firefighting. To that end, Airbus Military intends to work closely with Zodiac to develop the military aircraft A400M.

The aim is to share skills in order to create a device which will be able to load a tank of water in its bunker. The empty tank could be replaced by a full one when the aircraft land. This technology distinguishes itself from its competitors, because the other firms create devices which load in the sea, by a trap door.



We focus on dimensioning the hydraulic system of water bombing from the aircraft. The aim is to create a computer program able to give the following output data : head height, exit velocity, flow rate, volume discharged. We are dealing with different parameters whose influence on water dropping is analyzed. The final programming step is to maintain a constant flow of water during the discharge.

An experience set at IMFT (Institut de Mécanique des Fluides de Toulouse) will let us compare our results with concrete situation.

Then, we are willing to link our work with current firefighting issues such as drop pattern on forest fire.


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