Originally Posted by
DaveReidUK
IIRC, this was even more prevalent on the Belfast service, hence the technique in general was referred to as an "Irish backup".
Yes, I remember the crew announcing it as such. In print it was described more officially as "We can leave once we are full; no point in a planeload of passengers waiting for the official time".
The technique worked where, for example, you had a 1700 departure from Glasgow due Heathrow at 1810, and also an 1800 departure the other way from Heathrow to Glasgow, both of which were expected to be requiring backups. If you could get the first section of that 1700 departure away at 1640 you could hope to be at Heathrow at 1745, turn round in 25 minutes, and be away as the backup to that 1800 flight at 1810.
One of the things of this hourly service was that passengers tended not to go for a specific flight but turn up in more of a steady stream. If a backup was operating, typically 10 minutes after the main section, the gate was kept open until the last moment and there were always a number more passengers turned up, which in turn relieved the next flight.
All the ground crew were on their mettle to achieve this sort of operation; great pride was taken in getting everyone away on time. I sometimes think of this when I arrive inbound at T5 to find that,
yet again, we have to stop and hold on the taxiway because there's nobody manning the gate to turn the stand guidance on.
