I believe that the RN pass mark for Pilot is the same as that required by the RAF - with a similar caveat regarding competiveness. Indeed, to even be invited to the AIB to compete for an aircrew slot a competitive pass is required in both the Pilot and observe batteries (see numeous theads on RN aptitude tests by people 'just' failing the Obs test)
The pass required to be considered for by the AAC is, however, 90 (same as UAS entry?) I believe. This is as all potential officers selected by the AAC undertake flying grading prior to being offered a commission in the regiment. It is argued that grading offers a better view of potential to make wings as opposed to aptitude tests.
Having sat the tests twice myself, I can say that there will be a certain all over increase in score or around 10% just by virtue of the tests no longer being 'new' to the mind. The Pilot battery is perhaps the hardest to 'train' for as this comprises the most inate of all the skills being tested for. The others, given a good period of maths; physics; orientation study, are relatively simple to prepare for.