British Airways Boeing 747-436 G-CIVM positioned New York JFK – Miami this morning as BA9153 to provide cover for sister G-CIVD which encountered a technical issue at Miami yesterday. G-CIVM would normally have operated the daylight BA178 New York JFK – London Heathrow flight, but this was instead operated by Boeing 777-236ER G-YMMG. G-CIVM then operated yesterday’s delayed BA208 Miami – London Heathrow as BA9604.