BF109 F 20mm nose cannon

[Pilot]

Placing of the cannon in the central position is not made in effort to give access to the pilot. But this was made in the WW1 when SPAD XII was created. Posibly the first single seat fighter to have central armament, with 37 mm cannon through engine shaft and one machine gun atop of the engine cowling. reload of the cannon was done manualy. it experienced some problems in engine vibration and smoke release after triggering. But some aces like Guinemer, Fonk or Nuengesser managed to fly succefuly on the type. Only 300 were build.

Situation with Bf109 is different. In basic design there is idea to make wing free and with no load inside, This is done with the goal of manuevring. Due to the lenght of the same weapon the rear part was placed inside of the pilot cockpit. It is not possible to do any amintenance in flight as well this is very complex job and intensity of combat could not give breath to any to make some repair in flight and then back in combat.

In the sphere of the construction all armament present system with variable weight. When the armament is fired there is difference in the weight and this could be very critical if this was not calculated precisely. In this way all of the armaments like the cannons or machine guns in the fighters are to calculated to have ammunition close to the centrla of gravity and make almost no disturb when the weight are going to be changed. Also the airplane is calculated with the erserve of stability and this could give some possible to fly even is it become less stable in some envelope.

So the position of the cannon is the result of the very precise engeenering calculation in the goal to get the best from the available airframe.