Here is another photo from the set that Capt F Cunningham's nephew sent me.
A bigger image can be found on my Blog
In the photo the serial number of the Bristol Fighter can be clearly seen in the photo D-7894 which should help identify when and how the crash occurred. I have had a look in the book "The Sky Their Battlefield" to see if I can find this incident but with no luck. I can find reference to the plane in the 48 Squadron article in "Over the Front". On the 5th September 1918 Capt. H.A. Oaks and Lt. T. Beck were flying in this plane when they shot down two Fokkers.
I suspect that the crash might have taken place after the war as on the back of the photo is handwritten "Cologne". Were 48 Squadron based at an aerodrome in Cologne after the war. I know that after the war they did a bit of a tour of Germany from my Grandfather's photos and some were taken near Cologne.
There doesn't seem to be much damage to the plane. My father in law said that if there was damage to the undercarriage then the plane could flip over.