Studies undertaken or supported by the AirTrack Forum - the 2004 OBC (Outline Business Case) study commissioned by the AirTrack Forum and subsequent detailed work completed on behalf of the DfT (Department for Transport) in 2005 - established the practical and economic viability of AirTrack.  The later study showed a very robust benefit:cost ratio of 3.6:1 with the scheme was projected to make an operating surplus.  

The AirTrack Forum believes its work demonstrated the AirTrack concept to be one of the most cost-effective rail schemes then under consideration anywhere in the UK.  It is a close fit with regional and national policies.

AirTrack is a very close fit with local, regional and national strategy and policy. It is identified as a priority project in the current approved South East Regional Transport Strategy, SEEDA's (South East England Development Agency) Economic Strategy, the Surrey Structure Plan and a number of Local Transport Plans. In Autumn 2004, the SRA (Strategic Rail Authority) stated that it viewed AirTrack as the second step in improving rail access to Heathrow, preceded only by Heathrow Connect (local services on the Heathrow Express route to Paddington). Heathrow Connect commenced operations in early 2005. AirTrack was the only completely new transport scheme anticipated in BAA's draft interim masterplan for Heathrow, published in Summer 2005.

Since 2006, BAA/HAL (Heathrow Airport Ltd) have been developing a specific and detailed scheme proposal - "Heathrow Airtrack", which substantially reflects the scheme concept championed by the AirTrack Forum, but now includes some important revisions. 

In July 2009, HAL submitted an application to the Secretary of State for Transport for an order under the Transport and Works Act 1992, seeking powers to construct, maintain and operate the railway and to acquire the necessary land and associated planning consents.  It was originally anticipated that a Public Inquiry in to the scheme might take place in early 2010, but additional detailed work on timetabling and level crossing downtimes has resulted in the likelihood that the Inquiry will be delayed to the Autumn of 2010.

Up to 10m passengers a year could use Heathrow Airtrack services, with about a quarter of those traveling to or from Heathrow Airport.

here. Please note that the AirTrack Forum has no responsibility for the content of the HAL application to the Secretary of State.