explain the 4 stroke combustion cycle...?
That's a question which would clearly demonstrate if someone had a grip on what happens. If they just put "suck squeeze bang blow", 0 marks.
When reading this, I was being reminded of a radio ad we have in the Netherlands right now. The scene is an intern who just joined a nameless company. Mentor asks "Okay, can you copy this document? You know how a copier works, right?"
Intern responds: "Yes. A powerful light illuminates the document. The reflecting light goes through a lens and ionizes the drum. The drum then rotates against a second drum covered in toner. Where the drum is ionized the drum picks up the toner and then rolls this on the paper. The paper then goes through another heating drum which burns the toner into the paper." (Or something like that.)
So... How much time do you get to explain the suck squeeze bang blow principle? There's always a smarta**e who wants to write a 500-word essay (or worse) when asked a question like that. (I would, probably...
)
But to be honest, the principle of a four stroke engine is background information but not exactly directly related to safe flying. A question on how to lean the mixture properly for best economy, without ruining the engine, would be far more relevant. Particularly on aircraft with only limited instrumentation - tacho only for instance.