The additional platform at Manchester airport cost £15m.
A heavy rail line from Horsforth would need some challenging engineering so it won't come cheap.
There was nothing in the Regional Funding Allocation programme for Yorkshire and Humber for 2006/07 to 2015/16.
The most likely (but still unlikely) scheme would be a "tram-train" peeling off at Horsforth.
The now irrelevant Masterplan (isn't it?) had dreams of a heavy rail line linking the airport to Horsforth and Guiseley in proposals up to 2016.