I42 , I'm guessing it's on his descent towartds LHR ?
OP , don't think Yeovil [ Judwin for the oldies ] . Normally see it regularly when FI'ing but not for a couple of months . I do not remember a hrd peri track around the all grass field . Lots of white /grey hangars on S side .
It's 13 years since operating into LHR so geography memory fades .
sorry I can't help further .
rgds condor