There is a fair bit of useful information in the 26 Sqn Summary of Events (AIR27/2405):
https://discovery.nationalarchives.g...ils/r/D8419436
It can be downloaded for free if you create an account.
The squadron was at Zeltweg at the time.
The entry for 9.8.47 reads:
"W/O Westwell, while carrying out an air test of "H Harry" experienced undercarriage trouble and, while his wheels were down, and he was just beginning to climb up after a run over the control tower, his engine cut and he was obliged to land in a field before he had time to retract his undercarriage or jettison his long range tanks. Unfortunately, the a/c overturned, and, although it was severely damaged, W/O Westwell was extricated by local Austrian farmers. The civilian ambulance service put up a very good show in bringing him back to camp. He crashed as 1203h, and, at 1218h, he was back at S.H.Q being treated for lacerations of the neck".
So it crashed very close to Zeltweg.