USMC, To answer your question, never on a 135, ever! Just lucky I guess. However, in hindsight it might have been due to the fact that they knew I had an A&P. But then I received the A&P between my Private and Instrument, so who knows... It's important to know all the systems of course, though my personal pet peave is fuel systems. There is still an awful lot of carnage due to folks not understanding their fuel systems or fuel related issues. Anyway; yes, tell them to back off and that you were flying airplanes when they were on the Evenflo!