Another Service which might be possible and Useful a Brighton-Gatwick-East Croydon-Herne Hill-Blackfriars-Farringdon-St Pancras Low Level-Acton Mainline-Heathrow T2&3-Heathrow T5 and then once the line is built Slough-Maidenhead-Reading.
That'll need some OLE in between.
And resignalling, and somehow increasing capacity on the Brighton Line, and Herne Hill, and West Hampstead and Acton Wells and the GWML relief lines, and Heathrow. But other than that…
I was taking in the Convenience of not having to change especially as Airport Connections have luggage.
Almost all airline passengers have luggage. A significant number of them who travel to the airport by rail change trains. It is not really an issue.
how many people are connecting between the Airports?
Close to zero. It’s an answer looking for a question.