This is how the air component of a global war is managed. The commanders would use little clips that would attach to the board to mark the status of each squadron. I must say I am a bit surprised at this. Given the size of World War II - huge - I somehow expect everything to be to the same scale. This is a global armed conflict, for Christ's sake, you can't fight it in a tiny office with pen and paper!
The flight clock. Squadrons didn't spend much time in the air. From takeoff to battle to back was on the order of seven to twelve minutes (although it probably felt longer for the person in the plane). A flight would be color-coded with the triangle closest to the minute hand when it took off. So, for example, a plane taking off now would be "yellow".