The new 5km double-track line will run from Langley east of Slough on the Reading – London Great Western main line southeast to the existing station at Terminal 5 at Heathrow Airport. The link will allow trains from Bristol and South Wales to access the airport for the first time.

Jacobs will produce a design for NR's development consent order which will be submitted in early 2016. Jacobs will conduct topographical surveys and geotechnical investigations, and carry out design work for tunnels, track and electrification. Jacobs will also provide environmental surveys and an impact assessment.