Tour of duty

For military personnel, a tour of duty is usually a period of time spent in combat or in a hostile environment.

[1] In World War II, Royal Air Force doctors had started to notice symptoms of battle fatigue in their pilots.

The Senior Medical Officer of the RAF station Biggin Hill intervened, after learning that a flight sergeant had flown 200 missions over two years.

A tour system was then adopted; the length of it varied, depending on the period, theatre, and operational requirements of the time.

In Bomber Command, the tour length was exceptionally based on the number of successful combat sorties (missions).

[4] The first B-24 crew to achieve this was Hot Stuff, but they ended up flying five more missions before returning to the USA to sell war bonds.

Following a tour of duty, sailors often have the opportunity to reunite with family, friends and other loved ones
The crew of Memphis Belle returns from their 25th operational mission, thus completing their tour of duty