RAF offer of employment

I went through the OASC recently and got a provisional offer, subject to completion of the familiarisation visit and a security check. I hadn't actually heard about the visit before and am a bit worried by how much they emphasised the fact that my offer is provisional until it's done - I know that there's another fitness test (this one with the 1.5-mile run outdoors instead of on a treadmill) but what else is there at the fam. visit that would endanger my application? Why were/are so many people getting dropped this close to IOT?

I'm also not sure what to expect from the security interview - I've been told it's up to three hours long but don't know how there can be that much to talk about. Does everyone get one or is it only if they spot something suspicious on your official records?

Don't misunderstand me - I'm hugely relieved to have made it through the OASC (on my second attempt, mind you), I just wish I knew when it'll be safe to celebrate.

Fam visit is both a formality and a test. Yes people can fail, but that's not too common, it's more a chance to, as the name suggests, familiarise yourself with the environment. You'll get your boots, maybe get measured for uniform, do a fitness test, write an essay about yourself (is that still done?) and that's about it.

Regarding the security interview, I'm guessing you're going Int? Search online for 'developed vetting'. There's some things on here about it too. It's testing your susceptibility to blackmail. Important to note there are no wrong answers, only dishonest ones: they will know if you're lying. Yes it gets personal, yes they want to know a lot of detail (including about immediate family, where they're from, etc), bank details, porn preferences, etcetc. But just answer honestly and you'll be fine. I remember mine well.

As for when it's safe to celebrate: save that till graduation.

Fair point about saving the celebrations! There is an essay mentioned in my fam visit summary but no preparation apparently involved, and as far as the fitness test goes I suppose I should be alright assuming I'm as fit as I was at OASC - preferably a little fitter. I'm going for ABM, is it only the Int. branch that gets developed vetting? I've completed a security questionnaire and have heard nothing back yet, I have nothing to hide but would prefer not to have to discuss e.g. my porn preferences with a government official.

That's a good point - I've moved on to running the 1.5 miles outdoors and it certainly presents its own problems, especially with no waypoints to gauge whether you're keeping a good pace. I guess I would have heard more about the familiarisation visit by now if it were a serious pass/fail element of selection but comments above about people failing it weren't making me feel much better, so thanks for putting my mind at ease.