Delays are possible with any airline, it makes no difference whether they're charter or schedule, delays can happen for any number of reason. The thinking is, is that if your BA or VS plane is unoperational for any reason that these companies have 'backup' aircraft but that 's not always the case, in busy travel times backup aircraft would still take hours to get ready, and once the scheduled take off slot has goen they have to requeue for another take off spot anyway. BA in particular have had enormous amounts of cancellations over the past few weeks (I know, I have a lot of paperwork on my desk!) but First Choice, Airtours, Thomas Cook, Thomson etc have hardly been affected at all.