Speedy, I see you are in BHX. It's worth noting that LHR LDAs are all around 3500m and AMS offers the same - ish. Some have additional 'undershoot' values of around 300m if you are pressed. The longest ASDA in the area is LHR09L at 3901m. If in "Mayday' situation, you haven't got time to search around for a suitable RW having extracted your LDR from the QRH - it pays to have an idea of what facilities are on offer at all times.
mcdhu