IRONCLOUDS: Mk 2 "Silver spear" heavy fighter

Mk 2 "Silver spear" heavy fighter for my personal project, that is called IRONCLOUDS.

Mk 2 "Silver spear" is armed by a 30-mm quadruple autocannon of high rate of fire and a double 12,7-mm machine gun in the rear turret, it has an aircrew of 3 people: pilot, flight engineer and rear gunner. The workhorse of the air fleet that can be used against any sort of foe (with different effectiveness).

IRONCLOUDS is set in the fictional dieselpunk world, inspired mostly by WW1 and Interwar periods, where the most important battles are taking place in the sky. This is possible due to "Fairy stone" mineral that was known for hundreds of years and was called like that for its ability to float in the air for fractions of a second after being shaken. If there is enough of it and it keep being vibrated under sufficient force it can allow heavy objects attached to it "not to fall" and float in air.

After industrial revolution it was used as a base for multiple airships of different forms and sizes from light recons and fighters to big flying ironclad warships (also called "Ironclouds"). The presence of such force in the air changed not only the aerial combat, but the combat on the ground too (who needs a big expensive tank that can get stuck in the mud and will be shot from the air by direct artillery fire?).