Quote: "What's driving the poor punctuality then? Is it the lack of segregation of arriving and departing passengers from the ROI still clogging things up when the glass doors are shut or is it Menzies the handling agent in comparison with BA self handling at T5? Or is it the ongoing malarkey involved in bussing?"
All this nonsense isn't helping!
Quote: "It appears to be a combination of all of the above as well as crew airframes and even baggage containers having to be moved from T5 across to T1.
Many flights to BHD and DUB have been delayed due crew rotation between terminals. A move for all routes to T5 may help improve performance."
Good idea, but LHR-5, as big as it is, is apparently not big enough for all of BA (and IB). BA still have flights out of LHR-1 and LHR-3.
It was a lot easier when it was LHR-1 for shorthaul BA and LHR-4 for longhaul BA.
In reality the delays problem it's probably a combination of all these factors on LHR-BHD, especially if EI experiences similar delays on this route.
Quote: "Surely though the key metric is arrival punctuality? Block times for departures from Heathrow to anywhere are usually padded to account for the inevitable delays queuing for take-off etc., so still being on the ground within 30 minutes of STD doesn't automatically imply a correspondingly late arrival."
Indeed it is! However, flights to/from LHR have had extended block times for years. It's to account for the time spent queueing to takeoff and circling while waiting to land.