Why does an aeroplane fly?
 

Ah - I understand the basics just!

What about an Extra though - the wing section is completely symmetrical and therefore does not produce lift in a conventional way. I realised I couldn’t explain very well how this type of aircraft generates lift. I would appreciate an explanation.

Aeroplanes fly because they want to. Helicopters, becuase they have to ;~))

(Sorry Whirly!)

Seriously - forget that cr*p about curved upper surfaces they serve out in O Level physics. A wing generates lift because it displaces air DOWN. The equal and opposite reaction is that it goes UP. Stick your (simetrical) hand out of the window of a moving car (you never did this as a kid? And you are a Pilot???). Tilt it (give it some A of A), and it goes up. Just like the Extra. Give it negative A of A, and it goes down. Simple.

SSD

The difference is that a conventional wing will produce lift at 0 angle of attack but with a symetrical section you need to fly a + angle to produce lift. The advantage is of course that it will do it as well whichever way up the aircraft is flying whearas with an asymetrical wing it will work very well erect, but NOT inverted.
If you think about a vertical climb the assymetric wing will produce lift and hence needs to be flown forward of the vertical to go straight up but the Extra will fly straight up when pointing that way.

They got a circular pole to generate lift! Seriously there is an excellent link to a site that explains it all really well on my thread about aerofils in tech log. Also if you want to experiment and understand it fully, NASA's website has a downloadable program called foilsim on their education page, lets you design and test aerfoils.

Enjoy,
Rusty.

What makes an aeroplane fly? Pound notes, me old..! :D

I recommend a read of John Denker's See How It Flies