[MaggieL]

My opinon of a lot of posters' intelligence has been confirmed by some of the posts on this thread.

Perhaps some folks will find it enlightening to hear about the time I did an engine run-up before departure on an ice-covered runway at Hazelton, PA. (The ice serving as a pretty fair analog of the aformentioned conveyor.) Engine run up involves locking the brakes and applying something close to crusing power to make sure the engine is running OK...and also involves testing other things that need to work when the engine is at cruise, like making sure both sets of magnetos are firing plugs, that the auxiliary fuel pump pumps fuel, that the prop pitch control controls the prop pitch, the vaccum pump pumps vacuum...I mean air...etc.

Anyway, usually you lock the brakes and apply power, engine revs up and various needles move as appropriate...and nothing else happens. In this case, the tire s had very little friction on the runway (well, taxiway, this was) and started moving forward, much to my chagrin, as I was not quite ready to get out on the runway yet.

So that day I took off without a runup...since I couldn't actually do one.

If I'd been lined up with the runway, had advance the thrust to full power, and had used a little bit of extra runway length to allow for the small amount of friction there was, I woudl have ended up flying without ever releasing the brakes.

It's all about the air moving past the wings...and the engine thrust will most assuredly move the airplane through the air quite handily unless something prevents it...like friction in the brakes and of wheels against dry pavement.