If you are planning flights in the Islands it is worth keeping this £30 permit up to date 'just in case'.
The crew at islay last year told me that they usually permit OOH operations without it if permission is granted in advance, but this situation could change at a moments notice of course.
As a lot of the HIAL airports have strange opening hours matched to commercial flights, it can be a neccesity for normal operations at many fields (Tiree, for instance, closed quite early).
Campbeltown is excluded as it is a military field really. Barra because it's a beach (no, really...)
Enjoy.
