BCal inaugurated its two transatlantic flagship services from London Gatwick to John F. Kennedy Airport (JFK) on 1 April 1973, followed by Gatwick — Los Angeles International a few days later. Earl Mountbatten of Burma was BCal's chief guest on board its inaugural Gatwick—JFK flight. (The flight diverted to Boston due to inclement weather in the New York area.) This occasion marked the first time that a British independent airline commenced non-stop transatlantic scheduled services on routes linking the UK and the US. Also on 1 April 1973, BCal replaced the two-letter CA airline designator – which was originally used to prefix all Caledonian Airways flight numbers and continued to prefix flight numbers allocated to transatlantic charter flights until 31 March 1973 – with the BR airline designator it had inherited from BUA at the time of its formation. This resulted in exclusive use of the BR designator as a prefix for all BCal flight numbers.