There were no clouds around on the test but the Nav would have expected to get a radar return from that very big Cumulonimbus cloud resembling Gan on the approach!! Hence the 'snag' no radar returns.
The Ekco 290 CCWR fitted to the RAF C130's was prone to overheating and losing returns. A period of cooling would allow the CCWR to function again normally. No fault found was quite a common occurrence due to intermittent faults. Aircrew do not snag things for the hell of it. I believe the Brittannia was fitted with an Ekco190 CCWR which may have been prone to the same overheating problem. The implication in the above story is that the Nav was incompetent which I do not believe for a moment. Certainly the technician was pushing his luck.
Why spoil a good story with the facts.
Last edited by DeanoP; 8th Apr 2016 at 09:24.
Reason: additional material