What happens when the aircraft goes tech?
OK firstly the EZY fleet is almost new and very well maintained. Secondly there is a system in place for using a spare aircraft and crew these days, to try and avoid the knock on delays of yore.
What happens if a BA ship "goes tech"?
In my experience most delays have been caused by missing/late passengers/late baggage and ATC slots - or a combination of both, (plus at LGW disinterested ground handling by Servisair.)