This should resolve the issue, however there must be some action from HRMC and most likely some unions to make it stick once and for all:
HM Revenue & Customs: Work out if you're employed or self-employed
You are probably self-employed if you:
run your own business and take responsibility for its success or failure
have several customers at the same time
can decide how, when and where you do your work
are free to hire other people to do the work for you or help you at your own expense
provide the main items of equipment to do your work
You are probably employed if you:
have to do the work yourself
work for one person at a time, who is in charge of what you do and takes on the risks of the business
can be told how, when and where you do your work
have to work a set amount of hours
are paid a regular amount according to the hours you work, and get paid for working overtime - even if you do casual or part-time work, you can still be employed
http://www.hmrc.gov.uk/leaflets/es-fs1.pdf
From this it is very clear, Ryanair pilots and other pilots can not be self-employed!
It is time somebody starts catching the tax evaders like RYR etc.