[P/O W. 'Moggy' Cattermole]

If your airspeed is only 21 knots how is the aircraft flying, I beleieve that your speed over the ground is 21 knots. Under your way of thinking if you are flying your 1964 Cessna 172 which you own at 91 knots into a 91 knot headwind then your TAS is 0, I ain't buying it

He's right, leastaways i think so. The Fiesler Storch could practically hover in a strong headwind.

If you fly into a 30mph wind, your will travel 30mph slower than if there was no wind. And aircraft could fly at 0mph in a strong wind; it has happened. Indeed, an old british first world war trainer, the Farman Shorthorn, could fly at about 25mph or there abouts. When the wind picked up over Salsbury Plain enough, it flew backwards. One instructor even landed it backwards (and snapped off the tail skid for his efforts).