Lewis gun
S.E.5 no. A4850, fresh from its packing crate, was extensively modified for Ball: in particular he had the synchronised Vickers machine gun removed, to be replaced with a second Lewis gun fitted to fire downwards through the floor of the cockpit. He also had a slightly larger fuel tank installed. On 9 April, A4850 was refitted, and the downward-firing Lewis gun removed and replaced by the normal Vickers gun mounting. In a letter to Flora Young on 18 April, Ball mentioned getting his own hut on the flight line, and installing the members of his flight nearby.