Mooncrest, if you're interested, (probably not)!! As there's been mention of test pilot callsigns, (AVRO for Woodford). Just remembered a couple but my memory isn't perfect for the locations so I stand by to be corrected but.........
NEWPIN. Followed by a number. i.e. NEWPIN 29 was, I think Hawarden during the 125 building years.
TARNISH. Warton?
BLACKBOX. followed by an alpha numeric. i.e. BLACKBOX DELTA. Bedford Thurleigh?
The thing that worries me is that I can't remember Hatfield's even though I worked them many times!!!! The various manufacturing sites were then linked by a DH Dove company service, (Brough, Woodford, Warton, Prestwick, and very occasionally Dunsfold). These aircraft operated on the aircraft registration and not on a company callsign. The only reg I remember was G-AREA. There was also a Farnborough callsign that was used for the Navajo MOD(PE) inter-site shuttle if anyone can remember. Oh! By the way, I'm talking late 70's, early 80's here.
Talking Dan Air...I was just coming on for a morning duty as the 727 flew through the 26 Localiser at Luton! Myself and the Supervisor retrieved the tail bumper from the debris!!! We just got it into the back of the Land Rover!
Spiney