Originally Posted by
Jhieminga
2. You could log everything in one logbook, but you would need to switch between the different rules for every flight as you switch using the two licences. If you ever need to show a certain amount of experience, it can get a bit complicated if you need to add up the accumulated hours on one licence only.
The problem with this is that you don't log according to the rules of the license you're using - you log according to what the authority wants to see. For example you couldn't fly dual IR training with an instructor and claim it as PIC to the CAA because you were using your FAA certificate, they would still count it as dual only.
Two logbooks or an electronic logbook are the easiest options. You could also use one logbook and log according to the most restrictive rule, or simply fill in each page as normal and not tally the totals - highlight rule differences and keep the totals on a separate piece of paper. There are so many options which meet the legal requirements, you could write it on a stone table if you wanted. Just make sure it's easy to pull out the hours that you need every time you apply for something.