Texas Instruments had a factory in Bedford and their Learjet fleet used to turn up from the USA. November Ten Ten Alpha comes to mind.
Was it 3M that used the callsign 'Mining'?
Eric Morecambe lived in a very nice area in Harpenden, prime 4+ holidays a year area yet kick up about airport noise. Having been in a garden in Harpenden when a so called hush kitted ROMBAC 1-11 took of from RW26 on a WOBUN SID, I don't blame him!