Cancellations due to snow
I understand the need for cancellations particularly at LHR with increased spacing requirements in poor vis / snow, but who decides which flights are cancelled? Does the airport operator say cut 10% of slots from each airline and the airline decides which flights go or is there some other methodology? Is there no contingency for extending hours of operation for the 1/2 weeks a year this is a problem or do the local residents' groups/CAA prohibit this?
The airlines get a lot of stick as do the airport operators for not being able to handle poor weather (such as R4 interview this morning) but I wondered who makes these final decisions?