Although the caption for the line up of Harts in this picture mentions Heston as being the location for this photo in September 1931, is this in fact correct since the air race from Heston to Newcastle actually took place on May 30th, 1931 and was won by a Klemm aircraft. I have also not been able to trace any other air race for Sept. 1931 London/Newcastle in the Flight Global Archive and suspect that there may be a possibility that this location of this photo might be elsewhere than Heston and that the incorrect details were applied.
According to information supplied to me, 600 Squadron only received their first Hawker Harts in January, 1935 and they left in May, 1937. Also the background does not appear to be Heston due to the terrain on the right hand side of the photo being slightly raised, at Heston the surrounding countryside is very flat. Could this be taken at Hendon or possibly Brooklands ?
I was under the same impression but the photo pre-dates 1935 as rudder stripes are present and these were removed some time in 1934. I have a copy of The K file which lists a number of Harts received in March 1933.