Maybe he just returned from a "beer run"

In World War II beer was delivered to the troops in Normandy via the drop tanks from aircraft.


Tangmere, Sussex, July 1944: in front of a Spitfire IX of 332 (Norwegian) Squadron, a standard 45-gallon Typhoon/Hurricane ‘Torpedo’ jettison tank modified for use on the Spitfire (because of an expected shortage of 45-gallon shaped or slipper tanks) is filled with PA ale for flying over to Normandy while an RAF ‘erk’ writes a cheery message on the tank. Is the man filling the tank a brewery worker? Surely. Is the beer from Henty and Constable’s brewery in nearby Chichester? It seems very likely... <50% from [link to zythophile.co.uk]