The most famous patent of a founder and technical scientist of Estonian origin. The fire control device for anti-aircraft cannons, invented by Karl Papello, sparked intense international interest. Orders for the equipment were placed by the British and Swedish Defense Ministries and the US Army, tests were also carried out in France. And with a good reason. Aircraft used in warfare during the First World War were difficult to hit with artillery and machine guns due to the constant changes in direction of the aircraft. It took an average of 400 missiles to shoot down the plane.

The automatic fire control device, developed by Karl Papello, made it possible to determine the location of the aircraft based on the noise of the aircraft, predict the trajectory of its movement and transmit the data to the cannon control unit. The automatic fire control device calculated the required shooting data, being able to take into account minor side effects such as wind speed and deflection of the missile due to rotation around its axis.