Delta Air Lines has ponied up the cash for a set of slots and will transfer its last flights to London from Gatwick Airport to Heathrow come April. This is not a surprise but it does leave exactly one flight by a big US carrier to Gatwick, London’s second airport. Yup, it’s US Airways flight from Charlotte — all Delta, United, Continental, and American flights to London and US Airways’ Philadelphia – London service use Heathrow.

So when does US Airways bit the bullet and acquire slots at Heathrow for its Charlotte flight?