Delays and cost overruns increased the programme cost to £1.5–2.1 billion in 1976, (£9.44 billion–13.2 billion in 2021). Concorde entered service on 21 January of that year with Air France from Paris-Roissy and British Airways from London Heathrow. Transatlantic flights was the main market, to Washington Dulles from 24 May, and to New York JFK from 17 October 1977.