After Strubby, Thorney Island was - well - "cushy". For a start, ATC were in one of the new "Gaydon" towers. No longer any need to climb a wet and slippery outside staircase up to Local in a draughty, leaky pigeon loft. Now you were in warm, air conditioned, triple-glazed luxury with a fantastic view through the eight window sections.
A separate console carried all the controls for airfield lighting. You had a repeat CR/DF panel, so that the place could, at a pinch, be run single-handed. If you wanted to go outside (say to fire a Verey cartridge or take an accurate bearing with a hand bearing compass), a little side door at the head of the stairs let you out onto the flat roof.
A floor down housed the big Approach room, SATCO's office and the r/t monitors. Below that,the ground floor housed Met, the little cubby-hole with a bunk for the night Radar man, a small workshop for the radar/radio mechs, somewhere for tea-making (vital), and the Usual Offices.
I've left the best to the last. Away on the far side of the airfield, sited to work runway 19, sat the GCA (a CPN-4, a radar which I had never seen before, and about which I knew absolutely nothing). For all its eight (or more ?) wheels, it never moved an inch (nor did any other CPN-4
AFAIK). Theoretically, it was mobile in the sense that it could be hauled from one airfield to another, but you would need a very powerful tug (it was not a prime mover). A runway change was quite out of the question, so that was one worry less.
So, before pontificating on this equipment from a position of total ignorance, I thought I should arm myself with some useful facts; our good friend Google turned up trumps with:
"radars
martinshough.com/aerialphenomena/Lakenheath/radarspecs.htmCachedAN/CPN-4.
Short range airfield surveillance radar, part of AN MPN-11A Ground Controlled Approach (GCA) system manufactured by Gilfillan. Self-contained ..."
(and if you read that, you'll know more than I remember - it seems that CPN-4 forms part of the MPN-11 system, and we have
MPN-11 on board to assist with any arcane questions).
Starting from the Tower, getting across to the Truck was quite interesting. The hamlet of East Thorney lay to the east of the airfield, and so the public road, which ran down the west side from Emsworth, crossed the airfield. The first set of traffic lights were just off the side of the Tower, then the road crossed the West taxiway, two runways, past the access track to the GCA and over the East Taxiway through the other lights to the camp and beyond. The lights were of course controlled by Local and it was amusing to watch the stream of cars, trucks, cyclists and double-deckers going through while a Varsity, both its Hercules smoking at tickover, waited patiently for the lights to change.
After Strubby, which had roughly as many movements per day as Heathrow (then), Thorney was a haven of peace and tranquillity. I would say that it was not nearly as busy as Manby. IIRC, the only users were the No.2 (?) Air Navigation School, with the Varsities and a few Meteor NF 11s for the high-speed exercises, and a detachment of 22 Sqdn with two "Whirwinds"(?) for SAR duty along the south coast. Other than that, we had the occasional visitor and transits and that was all.
As all the School flying was done by 'old hairy' Staff pilots, who instinctively knew their positions within ten miles anywhere at any time in the UK, Approach was not overburdened with work, and I don't remember doing
any Talkdowns in my 18 months there, but suppose I
must have done
some.
To say that the CPN-4 was luxury in comparison with the Bendix was an understatement. The seats were little armchairs; no need for a Director or Tracker any more, for in front of me were two big tubes, one over the other, the PPI on top, going out to 60 miles, and the PAR, (out to 10) below, with both centreline (above) and glidepath (below) presented electronically on the same PAR tube. No more perspex cursors !
The tubes were amber-lit, much easier on the eyes, and we had
Moving
Target
Indicator. This crafty gubbins compares the return time of each pulse with the one before, and rejects all which coincide. You can have this in or out as you please, mostly people just set it far enough out to wipe out close ground returns (up to 3-5 miles). There was a trick: circuit traffic is at times moving in a circle around you, its distance from you does not change, so nor do the pulse return times, MTI will not show the blip.
I am indebted to
MPN-11 for the information that there were three identical consoles in a line down the Truck, for I can remember I always took the one nearest the door, but only vaguely recall how many more there were.
Now that is quite enough for the moment, so more about it next time.
Goodnight again,
Danny 42C.
Some people have all the luck.