This issue was previously discussed here:
Ryanair Brookfield False Self Employment? [Archive] - PPRuNe Forums
Main point being if you are a Ryanair pilot living / working in the UK as a contractor, enjoying the benefits of tax efficient dividends through your ltd co, then you could potentially get a knock on the door from HMRC who could demand a significant amount of cash going all the way back to day 1. It seems there is little doubt that this scenario fails the test of genuine self employment and therefore lies inside IR35.