That fuel feed problem
Fuel feed was selected by levers located on the forward side of the centre console, ahead of the throttles ( two sets ). It's a while ago now, but I seem to remember they were selected into detents, as you might expect. Tests conducted by the R.A.E. appeared to show that the rotary fuel cocks operated in sequence could - in the Stockport case, at least - have been incorrectly aligned to the tune of several degrees. This, in turn, it was found, could have allowed migration of fuel from the mains to the auxiliaries. I assume mains would have been the normal feed selected prior to the approach phase. Anyway, it was the misaligned valves that were cited as the chief cause. I suppose, the accident report can be found somewhere on the internet, and I can imagine that in it will be other stuff covering cross-feeds, quantity indication, maintenance etc. etc.