Self Employed
A major change decided by the Special Commisioners was that you can be what you say that you are. The Revenue had always disputed this saying that you are what their rules saids that you are. In my opinion the Commioners have clarified that two parties may agree a work status, self employed or employed. Of course that also needs to be true in how you do it. It is important how the two parties verbally or in writing make the agreement.
A major element of the Commisioners decision is that the Contractor (the Flying School) may provide the facilities, equipment the aeroplane and also find the work - take the bookings and also the money but contract you to do the work for an agreed fee per hour flown. In the case of Mal Scaffolding the Inland Revenue disputed this point and lost. However I believe that there will be a difference between being paid for your time in attendance and solely being paid for the hours flown. Most Instructors are of course paid by the hour flown and receive nothing if not. Should an Instructor be paid a basic wage, set hours (even if varied) and flying pay as a commision on top I suspect that they will still be treated as employees. A daily guaranteed sum against flying time may be treated differently. A requirement that you make yourself available between certain times to undertake work as it may arise could be asked of any sub-contractor. It would be reasonable to make a charge for this standby service given to the school. Such a scenario wasn't tested however in the case of Mal Scafolding Ltd.