all depends on where you took the photos if you were on public ground then you are safe if you took the shot on the ramp (i.e airport property) then you must follow all instructions on what you can and can not. It's up to the land owner if you can or can not take photos, if they say, no then it's not permitted if you take the shot and then get told to delete the shot that's where it's a gray area. your best course of action is ask first and then if granted take the shot, if told not to then you will need to put the camera away.
This guidance relates to Uk only.
Hope his helps.