The English Electric Radar Flight Trials, at Defford, were conducted as part of the research associated with the development of the new Thunderbird 2 GW system
This missile employed the innovative CW radar, which opened up new areas of unknown particularly regarding the radar characteristics of ground/sea (reflections) and aircraft.
The Semi active system used CW radar and discriminated between targets by means of their doppler shift. As a semi active system it employed a high power ground based illuminating radar, the missile was fired blind and acquired the Doppler shifted signal from the target.
The trial trial involved the measurement of the amplitude and frequency spectra of ground and sea, when illuminated by a high power CW radar. The airborne platform was a Shackleton VW126 fitted with a coherent three channel radar receiver.
The trials were conducted by using the ground station trained along a steady bearing to illuminate the ground/sea or target. The Trials aircraft flew a reciprocal course directly towards the illuminating radar, whilst training the rear dish at the ground/sea or target.
Multiples runs were conducted a various altitudes and dish depression angles, for a range of bearings. From sites in the Defford area (such as to sample different types of terrain,
The process was repeated over sea, from a site at Portland, sampling a range of sea states.
Finally a series of runs were conducted with several (Canberra bomber & Gloster Meteor) aircraft targets. For these runs the target aircraft started further out, than the Shackleton, and flew the reciprocal bearing, overtaking the Shackleton, before breaking off. The rear dish was trained on the target (presumably manually, initially) before velocity and angular lock was achieved.
Most of the trials were conducted from Defford airfield. However, when the airfield closed operations moved to Pershore. I don’t recall much about this phase of the operations. I guess I was only there for a short period. Also around this time English Electric’s involvement was winding down and the equipment transfered to RRE and we were involved in training RRE staff to take over.
Reposted from Missile Review – April 1957
Interior Shackelton VW126, April 16th 1957. Showing Green Flax (English Electric) Flight team- Probably – Alan Burton, Ron Coultart, Keith Watkins (reading left to right)
The team were billited at the Crown Lea Hotel, Barnards Green, Malvern and had a support building at Defford, in addition to the exclusive use of Shackleton VW126