Registered: 23/03/01
Posts: 1906
Loc: San Jose, CA
Great. On a windless day, if the engines are off the aircraft has neither airspeed nor groundspeed.
OK, now, let's place a conveyor belt under the aircraft's wheels, and bolt the plane to the ground by its nose, tail,and wingtips. Now, let's fire up the conveyor belt to 30mph.
It's still a windless day. Answer these questions: 1) What's the aircraft airspeed? 2) What's the aircraft groundspeed? 3) What's the aircraft's wheelspeed on the conveyor?