Just saying, I think that the information on the data base for Doncaster Sheffield Airport is slightly incorrect. Although being a military base for many years (since 1915), it was only in 2005 that it was opened for public flights. Where as in the Jet Age I realise that it was open at the start of the game in 1965.
http://en.wikipedia.org/wiki/Robin_Hood_Airport_Doncaster_Sheffield
Thanks
Jake