What none of the rail operator sites say is if the Heald Green to Airport buses are "rail replacement" and therefore included in the price paid if you have a rail ticket from/to the Airport, or a free bus operated by Manchester Airport/Network Rail to and from Heald Green Station from the Airport or whether normal bus routes are to be used and passengers have to pay. If the latter, it would be nice to know which bus services you need to catch and the frequency.