In the late 80s I was working not a million miles away from the DET in a secret suffolk airbase, within a much more well known suffolk airbase and was talking to crew chief in the nearby local ( three horse shoes higham top pie and chips)
He was asking if I knew anywhere they could get 99.99% pure Nitrogen as the cockpit of the HABU was pressurised with the stuff. BOC could only supply 99.96 or sum such and I asked him why 0.001 was so important. He told me that it was because they flew so fast and the cockpits were getting so hot they had a few spontanous ingnitions. I asked him how fast they where flying as I heard Mach 3 and change, he replied Yeah that's how fast " they" ( other side ) had gone and each time they fly faster we just put the hammer down a little more and we have plenty left.... Ramjets doncha know, inlet generates 99% of the thrust and the more we open them, the faster we go.
On the fuel side he also told me you had to light the fuel with a blow torch, apparently one of the tanker guys tried to light a BBQ with it and it just put everything out, it has to be ingnited by paladium catalysts or some such in the J79.
Might just be bar talk...be interested to know if it wasn't