Even though in Lincolnshire Binbrook wasn't flat.
I had a look at the OS 1:50k map - there is a 113m point roughly where the threshold of 03 was, the 21 end was approx 97m so 370 ft to 320ft, you pays your money etc. When eating my Cathedral City at my lowly 55m I thought whoever stuck an airfield up there must have been totally bodmin, to use the venacular, maybe they thought it would normally be above the cloud. (Addendum: Cathederal City is manufactured alongside the former RAF Davidstow Moor - but I forgot to meention it was that airfield)