Why did World War 2 fighter planes have numbers on them?

Answer 1

Airplanes, espeically the military planes in WW2, were painted with numbers and symbols to identify them. Some numbers were the identification of the airplane. Some numbers were used to identify the airplane within the squadron.


For example, the number painted on the tail of large bomber was the aircraft serial number that was assigned to it at the Factory. These numbers were used to keep track of the aicraft throughout the war and to track its maintenance records and such.


Then other bombers would have a 2 or 3 digit number painted on the nose. These helped identify the number within the Group or Squadron. It could have been the radio call number identification used to talk to each other. Each plane could have nose art & a Name painted on the nose but this was used for morale only and not for a call sign.


The Germans in WW2 would identify many of their bombers, fighters and other planes with 4 numbers/Letters on the fuselage; 2 on each side of the National insignia (+). The first two letters/numbers would identify the Bomb Squadron and the last two would identify the aircraft within the unit. Usually the 3rd letter would be the aircraft's number.


British fighters used Letters placed next to the national insignia(roundel). You can see early Spitfires and Hurricanes with these letters. A pilot who distinguished himself would be allowed to use his initials instead of the squadron's letters. For example, ace Johnnie Johnson's aircraft was identified with "JEJ".


German fighters were generally marked with an aircraft number forward of the National insignia (+). Aft of the + insignia was a symbol that identified the Staffel(squadron) and would be a - or a Bar(|) or a "~". They used colors---black, red, yellow, blue---to also identify which staffel of the squadron and the aircraft number was the same color. It was really very simple. The leaders of the Staffel were painted black as they lead all the staffels. The leaders were marked with a Chevron or double Chevron that was turned to point Forward.

Answer 2

All military aircraft have numbers assigned, not just in WW2, but before and after that. All American military planes have what is called a 'Bu Number' , this is a 5 or 6 digit number that follows the aircraft till it is scrapped. In each unit they are sent to, there will also be a Squadron or Wing number and often an emblem, especially in the US Navy and Marines.
All British military aircraft have a 2 letter, 3 number coding, for instance a Buccaneer that I worked on was XK527. These are usually written small under the tail and large under the main wing. Many RAF Squadrons also identify their planes by a a larger number or letter on the front fuselage or tail fin.