A statement of principles agreed between Heathrow Airport Limited and the secretary of state for transport includes an indicative timetable setting out when both parties expect to achieve key planning milestones.
The airport is targeting a construction start date of 2022 and intends that the new runway capacity is operational and in use by the public by 2026.
The application for Heathrow’s new runway will be determined under the Planning Act 2008 regime for nationally significant infrastructure projects.
According to the statement of principles, the government has committed to designate a National Policy Statement (NPS) on airport capacity, which supports the development of the scheme, "by no later than 31 July 2017".
The Department for Transport said earlier this week that a draft version of the NPS, which will guide the planning decision on the new runway, will be published for consultation in the new year.
On the basis of the NPS being designated by the end of July 2017 - and a number of other "key dependencies" being satisfied, such as changes to UK airspace - Heathrow Airport will submit a development consent order (DCO) application for the new runway by March 2020, the document says.
It adds that a DCO could be secured for the scheme by September 2021, "subject to the progress of the application after submission, including any suspension of the examination and any extension of the decision period".
The document acknowledges that the indicative timetable is dependent on "third party support", including from "host and neighbouring local authorities in respect of local road network and other associated local development assessments".
Statement of Principles relating to Airport Capacity Programme is available here.