I hope the Davies Commission is more receptive to alternative ideas for expanding LHR passenger capacity than FR- and Skipness One Echo !
Way back in 1952 Northolt handled 50,000 atms, so they should be able to handle the same today. All I am suggesting is decanting the smallest existing LHR aircraft, requiring the largest wake separation distances, to NHT; thus freeing up capacity for additional larger aircraft on LHR main runways.
And I don't think we should be side tracked by talk of an expensive rail line from NHT to LHR as the A312 is a perfectly good dual carriageway road from the A4 at Cranford to the A40 Target Roundabout (or the Polish War Memorial). There is a tube station nearby at Ruislip Gardens for direct access to London and an A312 taxi or bus service should be adequate for transfer pax to LHR.
Publically available information is available at
RAF Northolt - Wikipedia, the free encyclopedia
Then we could free up some more capacity by decanting the LHR holiday charter flights to LGW &/or STN !