Unfortunately being an RAF engineer doesn't actually mean you are given testicles made of gold and the ability to perambulate over dihydrogen monoxide.
RAF training is still decent, but engineers don't do nearly as much in the way of deep rectification as they used to. All too often things are passed back to industry which would have been beneficial in terms of skills retention and pure interest to do in house. Assessing a monetary advantage, or lack thereof is more difficult; but being as defence logic can rely on thinking that because someone is employed by the Service their work is therefore free and diversions a lossless exercise we can make the bold presumption that handing such work to industry is expensive *if* it can still be done by the Service without excessive diversion.