Originally Posted by
ORAC
But the Vulcan relied a lot on the range calls by GCI to know when to start the turn. .....
ORAC very true, but when I did a quick survey of Vulcan crews in the late 60s there were about 20-25% that had a Russian speaker on board. Given that there were only 4 GCI freqs this was not necessarily rocket science.
During WW2 the Luftwaffe used a call Emil Emil. The Y-service soon deduced that this was exactly the same as Tally and later Judy.