The scalloped trailing edge (often indicative of a wire , not wood or steel tube member) is not typical Avro.
What is the member coming down to the lower left corner of the image? Possibly going to a skid? If so , not part of a central skid assembly as on the Avro.
It appears ( although it might be an illusion) that there is an under fuselage cabane down to the lower wing. Again, if so, not Avro 500.
Adding these features together they would all correspond to a possible Caudron G. II trainer variant, of which one at least went to the RNAS.
Last edited by Haraka; 24th Aug 2020 at 10:40.