8 of 12Lascaris War Rooms
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".
Albums: Lascaris War Rooms, Malta 2012