[niffydroid]

^ this. My father is an aerospace engineer. He has worked for many companies and in various positions, director/head of engineering/certification across various sectors. He now works for the regulator as an auditor and specialises in the sectors he has worked in and often with companies he's worked for. There is a huge amount of integrity involved for the profession and I've never heard of any cases where this has been questioned. At the end of the day, there are rules and processes to follow, don't follow them and it's quite simple you loose the power to verify your own work, no business wants this and it's much easier to work with the regulator and conform to the rules. Also if the regulator determines there is an issue or fault then they can ground the affected aircraft, in a number of cases the airlines/manufacturer even have clauses with these companies that are the along the lines of "if your product grounds us, you will pay us x amount per day" The regulator will also specify how much cost to rectify work will be so the company will lose money, that's why it's easier to just follow the rules!

I should add that the regulator will be to the letter. I was told a case where the company followed the test form a spec from standard x, but standard x was superseded twice. The latest spec and standard x, the testing was exactly the same but because the company had done the testing against x and not the latest they had to redo all the work. Regulator would not shift or give dispensation on passing it.