I recently came back from a trip. BOS-LHR-VCE and VCE-VIE-TGD on British Airways and on Austrian. I managed to see 5 UA Aircrafts sitting on the "remote stands" Three 767s and a 757 in LHR (I confirmed that they were cancelled after looking up their tail #) and a B767-400 in Venice. (same as above) UA REALLY needs to find a solution for all these MX Issues , glad I flew BA on the trip (in fact we were looking at that same flight back from venice but we chose to add on a trip to TGD.)