Hi arriving on a BA flight into LHR T5 at 10:05 in the morning on a Thursday. Ryanair flight departing Stansted at 15:05. Planning on taking a National Express coach at 11:05 arriving at Stansted at 12:50. This theoretically would work fine. But is that unrealistic to expect of BA to get checked bags and be on the bus within an hour? The next coach isn't until 12:05 and gets to Stansted at 14:10 which is cutting it too close.

Thanks!