Re SMT comment-I agree- a pretty frequent occurence I recall the BA terminal has at least two very tight gates and manoeuvring on to them might require a bit too much push from the engines to safely manoeuvre and I also think there are issues at times when most of the gates are occupied . I think that 'across the road' at JFK in the AA terminal there are a couple of very tight stands and 757s had to be pulled on to the gate and after push back pulled a long way forward