BA777ER236 From United Kingdom, joined Sep 2006, 278 posts, RR: 8
Reply 7, posted (6 years 7 months 2 weeks 4 days 10 hours ago) and read 5519 times:
Quoting Mir (Reply 6): But the facilities at SWF, particularly for international flights, are pretty minimal.
Yes, but generally we wouldn't disembark passengers at the diversion airfield unless there was no prospect of departing again before the crew went out of hours.
On the whole, these would only be used as 'fuel' alternates. This means that it would only be used if diversion was unforeseen. If the likelihood of a diversion was high before departure out of LHR, then we would load fuel for a 'commercial' alternate which would have the facilities that you are talking about. A 'fuel' alternate is used for just that. The idea would be to 'splash and dash' i.e Take on fuel, complete the loadsheet, file a flight plan and then fly back to the original destination, assuming it is open/suitable again.
Normally we wouldn't carry fuel for a 'commercial' alternate because that would often mean carrying significantly more fuel. On an 8 hr flight we would burn roughly 32% of that fuel just to carry it. So if we carried an extra 3 tonnes(metric) of fuel on a 777 just to cover a 'commercial' alternate then we would burn a tonne of it just to accomplish that. Today, that would be an extra cost of approx $1300!
What they do have is either a US Customs post or an arrangement with a local office so that the aircraft can clear customs at first point of landing or have it officially deferred until arrival again at the original destination.