John Innes Brown III with his dog, at Kirton-in-Lindsey, 26 Nov. 1941
John "Red" Campbell remembered being his roommate, and bemoaned the fact that his dog "wasn't necessarily housebroken."
Entries of the day this photo taken and newsreel filmed are within the No 121 "Operations Record Book" at The National Archives in Kew: "Various news-reel personnel came to take moving pictures and stills of the squadron to-day."
Entries show him as taking to air, likely piloting one of the Spitfires you see in the video.
From "Movietone News" newsreel "Second Squadron With the R.A.F."
You will see John I Brown III (and his dog!) at 0:05 - 0:21
British Movietone: "Second Eagle Squadron"
AND find this (and a bit more) packaged in a 5 newsreel Video on YouTube by "Bomberguy": "RAF Eagle Squadron"
("American Squadron with the R.A.F.", "The Eagle Squadron", "American Eagles Go Into Action", "Second Eagle Squadron", and "R.A.F. 'Eagles' now fly for U.S.A.") :
In this package, you'll see John I Brown III's Squadron, No 121, beginning at 4:22; see him on the left at 4:28 and 4:41 then recognize him with his dog at 5:31-34.
'On 14 May 1941, No. 121 was reformed at Kirton-in-Lindsey as the second 'Eagle' Squadron to be manned by American volunteers. Equipped with Hurricanes, it began defensive patrols in October but in November it converted to Spitfires. It moved to North...
Military | Captain | Pilot
Joined RAFVR, service pilot training in US, shipped overseas to ETO, operational training at OTU, assigned to 121S, transferred to 82FS, 78FG, 8AF, Tour expired ETD.
Military site : airfield
Used as an RFC and RAF Home Defence landing ground during the First World War, Kirton-in-Lindsey was built during 1938-40 as an RAF fighter station. It had two grass runways, 10 hardstandings, three grouped C hangars and four over-blister hangars....