25.000+ feet? 27R/09L at LHR is 10,000-ish..IIRC
I don't think even NBO or HRE are that long...
From my days chugging up and down MME-LGW on a shed, I seem to recall that Cottesmore's is longer - there was always the chance to compare the two when passing overhead. There was also plenty of time to watch the trains on the east coast line that appeared to be overtaking us.... :-)
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