After the completion of his training he was gazetted 2nd Lieutenant to the Royal West Surrey Regiment on the 21/06/15 and promoted to acting Captain in Jul 1916. He then took up signalling and became the brigade Signals Officer in July 1916. Hubert joined the RFC in August 1916 and graduated as a Pilot on the 05/02/17. He flew to France on the 14/02/17 to join 57 Squadron. On the 02/04/17 Hubert was piloting one of two aircraft on a patrol, a FE2d (A1944). When the aircraft was some distance over the enemy lines, between Arras and Cambrai, they were attacked by six German aircraft, two of which were shot down. Both the British aircraft were brought down and the observer of one aircraft was taken prisoner. He reported that both Lieutenant Sworder and his observer, Second Lieutenant Henry Margoliouth, had been killed.