Found this pic of N428NA at Heathrow dated 1971

Douglas C-118A, N428NA, NASA

I wonder if that's one of the Froggy Falcon 20 calibrators behind it.

I think you'll find that had nothing to do with ATC calibrations; it was used to calibrate the NASA spacecraft tracking station at Winkfield Row, Berkshire. I was working at LATCC West Drayton at this time and we often got UFO reports triggered by this aircraft as it used an array of strobe lights, normally in the early hours of the morning.

Chevvron is on the ball...

El Bunto In the 70s we were using Doves and Avro 748s and I do not recall Falcons being used in those days.

http://i1297.photobucket.com/albums/...ps0r6yr8su.jpg

A blurred snap of a youthful me about to go for a jolly in the CAFU HS125 in 1983.....

I did several trips in the 125's and the Navajo, but not the 748's, although I had a couple of flights in the RAF Andovers during my service career.

DH

Perhaps my terminology was a bit obscure. The French flight cal unit used Falcon 20s until the mid-1970s when fuel-costs forced downgrading to Nord 262s.

The mob used to use the old Whistling Tit back in the 70's. I remember it doing the cal at Coningsby. 115 Sqdn from Cottesmore as I recall.

NAV CANADA presently uses a Canadair Challenger for aerial navaid inspection and calibration.
http://i1047.photobucket.com/albums/...CHALLENGER.jpg

Wyton too as I recall!

If the "Whistling Tit" is the Argosy, it was also used at Farnborough & sundry other RAF airfields.

CAFU nostalgia
 

A very good book on the history of the Civil Aviation Flying Unit was recently published by Jim Fuller who worked for them for many years. I first met Jim at Stansted in 1962 when I was an ATCA in the tower. The Doves were principally used for pilot examinations, including IR tests. CAFu also had 3 Percival Princes and a President as well as 2 Chipmunks, in the sixties. I enjoyed many a ride in the right hand seat of the Doves from EGSS as a lookout pilot.

The one based at Farnborough was used by ETPS, nothing to do with calibrating ATC equipment, but the Wyton based ones visited every 6 months/180 days to flight check the PAR until the were replaced by Andovers. I also remember one doing a commisioning flight check on our (then) new digital readout DF; we were still giving it Class A bearings when it was overhead Wyton descending to land.