British Airways Boeing 777-236ER G-VIIF overnighted at Boston after arriving as BA239 from London Heathrow yesterday evening, however it did not operate the return BA238 this morning. There was a spare Boeing 777-200ER at Boston following a technical issue yesterday and there were adequate crews at Boston to operate both today’s BA238 and a positioning flight. As G-VIIF remained at Boston for a second overnight it appears to have encountered a technical issue.