How often were LORAN and or astro fixes required? Was there a separate nav station in the flight deck?
Fixes were required every twenty minutes. There was a separate nav station. On the 707 it faced sideways whereas on the VC10 it faced to the rear behind the captain.
The periscopic sextant was pushed through a mounting at the rear of the flight deck. A two minute 'shot' was taken of the star, This was done by keeping the star in a bubble using rocker switches on the side of the sextant. There were drums on the side of the sextant which would give the average reading over the two minutes.
Operations into JFK were different in the mid 60's as Terminal 7 had not yet been opened so we operated into what was then known as the International Terminal.
As far as I remember, the lateral separation was 120nm (perhaps an ATCO could confirm). On a bad night for Loran we were sometimes 20nm off track when we came into VOR coverage. I think that 60nm came in later but am happy to be corrected.
The nav would sometimes call one of the weather ships for a chat. They would always give us a bearing and distance as well as their position. On one occasion a weather ship asked us for our position. Apparently the sea was so rough that they had been unable to get an accurate fix.