Hull and two other pilots, South African Pilot Officer Jack Falkson and Naval Lieutenant Tony Lydekker, volunteered to be detached to an improvised airstrip at Bodø, a port about south-west of Narvik, on 26 May 1940 to cover Allied troops who were retreating north for evacuation under Operation Alphabet. Arriving to find the airfield extremely muddy, the pilots had great difficulty moving their aircraft to drier ground to refuel from four-gallon (18-l) tin cans. A He 111 was spotted overhead while this was in progress, prompting the three pilots to scramble having only partially refuelled. Falkson's plane crashed after mud clung to its wheels, and while Lydekker took off successfully, he had so little fuel that Hull almost immediately ordered him to land to add more.