I suggest you post your thread at The Great War Forum under the "War in the air" section. There are some RNAS experts who would be able to answer your question.
don't have much I'm afraid. There was a C Williams under training at Eastbourne in the latter part of 1915/early 1916. He wrecked a Caudron GIII on 20th December 1915 and damaged a Bleriot II on 14th Jan 1916.
One positive in a negative sort of way, he was not listed as a member of the RNAS in November 1916 - maybe he was "washed out" during training?