Estimates resulting from work undertaken in 2004/ and 2005 on behalf of the AirTrack Forum and DfT/Railtrack showed a projected cost for the scheme of between £350-400m, including the very large contingency figure required by the Government.

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. Full details of Heathrow Airtrack and the application, are available via BAA's Heathrow Airtrack web page (see links elsewhere on this website).

Cost inflation, changes to engineering requirements and alterations from the scheme as evaluated by the Forum, have resulted in the costs for the current Heathrow Airtrack proposal now being estimated as being of the order of £700m.

If permission for the scheme is obtained, the final challenge will be to put together a funding package.  In its application to the Secretary of State, HAL indicates that it will fund the cost of implementing the proposed Order partly through its own resources and partly through an application for funding to the Department for Transport (DfT)

HAL has established that the Airtrack scheme provides incremental benefits beyond the users of Heathrow Airport. A funding contribution to implement the scheme will be sought from central government in accordance with the principles set out in the Aviation White Paper (2003) and subsequent DfT guidelines on funding as set out in Funding Transport Infrastructure for Strategically Significant Developments (April 2009) to reflect the shared benefits.

The DfT has indicated that the scheme will be considered for a government funding contribution in line with the guidelines Funding Transport Infrastructure for Strategically Significant Developments (April 2009)