Looks like it flew for 40 minutes before returning to Logan on 5/14... anyone have info on the reason?
From the flight profile on FlightAware, it seems they may have encountered an issue about 10 minutes into the flight as they stopped gaining altitude at about that point.
Do they have to dump fuel over water before landing again so soon?
BOS to LHR is a relatively short flight for this aircraft type. If it was only one hour into a 12 hour flight, it would be necessary to dump fuel, but it was almost certainly not necessary to lighten up for a 7 hour flight segment. The plane did depart for London about three hours after landing back in Boston. That period of several hours may have been crew related and/or the need for an overweight landing inspection by mechanics as it was likely a technically overweight landing.