A Swiss diversion
It is not common for Swiss aircraft to be diverted to a different airport, so why was the Geneva to London City sent to Stansted?
The Geneva airport Web site did not show it, but the LX442 flight yesterday morning, 6 January 2014, from Geneva to London City airport was diverted to London Stansted. Looking at the flight plot shows that the aircraft left Geneva on time, but then circled around south of London City airport before going instead to London Stansted.
Why did this happen? No idea, especially as all other flights to London City airport arriving at about the same time had no problems. Doubtless the passengers were give some explanation of why they were going to have to take a long, probably rather slow, bus ride to central London.
The aircraft then flew empty back to Geneva, thus cancelling the planned return from London City to Geneva. I would guess that they got a flight not too long afterwards, but who knows what they were told.
A similar sort of thing, but in the reverse direction, happened last Saturday, 4 January, at around 10pm. There was clearly some problem at the airport, since several incoming flights circled around for a few minutes before being able to land. For the easyJet flight from Madrid the pilot does not appear to have wanted to circle: he soon decided to divert to Basel. Similarly, a Swiss flight from Majorca diverted to Zurich. However,four different aircraft did circle around a while and then land directly in Geneva.
What I do not know is how long aircraft can wait around before being diverted. Clearly, before leaving wherever they came from, aircraft must have enough fuel to divert to somewhere else, but extra fuel adds weight to the aircraft, so probably adds to the cost. Thus, airlines will not want their aircraft to carry much more extra fuel than the regulations insist upon. A delicate question!