A student is not expected to question his instructors competence. He is not yet qualified. He is Pu/t, not P2.
Not so - or not necessarily so.
As an experienced helo pilot used to military instructors I was doing my B rating on a Seneca with an outfit at Lydd, thankfully long gone. Next morning at LeTouquet on engine start the aeroplane began to trundle across the apron. Total brake failure. I insisted they replace the aeroplane. Why, said the instructor, we are only doing circuits and bumps, we don't need to stop so why do we need brakes. I kid you not! I had to insist. Really forcefully. It wasn't easy as I was the stude and imagined this paragon, being an instructor, must know something of what he was doing. How wrong I was. He didn't event know there were equivalent tables to see which Mobil brake fluid would do either, nor where to find them. He was a complete numptie. He later nearly killed us later doing a self let down through cloud into Headcorn which I was most uncomfortable with but thought be OK as it was on IR training - until we popped out over high ground somewhere near Cantebury in 400ft cloudbase miles from where he thought he was. I wished I had objected to that too. Stopped the cheque for that day's flying and never heard a peep!
Moral, studes, if in doubt, speak out! Instructors are not necessarily SkyGods.