Content Wrapper

[Mr. Plow]

Well I took the time to read all 11 pages, and being a pilot I will put in my 2 cents (whether my thoughts are worth that much is up to debate). I agree w/ the air flow guys in that the plane WILL NOT take off w/out the sufficient airflow over the wings to produce lift. It does not take too much thrust to get a plane moving so it can be reasoned that the friction created by the wheels against the movement of the plane is low. It therefore doesn't matter if the plane is on a treadmill going 100mph, it will take very little thrust to keep it in a relative position on the treadmill and by adding thrust the plane should accelerate through space while riding along on the treadmill. Now if you have a treadmill as long as a runway, then I agree that a plane should be able to accelerate to take off AIRSPEED even w/ the treadmill moving in the oposite direction; however depending on the speed of the treadmill, the wheel bearings would eventually give out. On the plane I fly the wheels are limited to 170kts Ground Speed. I think it can be agreed that if a plane is maintaining the same speed as the treadmill but is not moving through the air that it will NEVER takeoff because there is no airflow over the wing. In aviation there are two basic speeds: airspeed and ground speed. With absolutly no wind airspeed = ground speed, but say you are flying at 100 knots airspeed into a 10 knot headwind. Your airspeed is still 100 kts, but your groundspeed is now 90 kts as the speed you are going over the ground has been reduced 10kts by the headwind. Takeoff speed has 100% to do w/ airspeed not ground speed; that is why it is prefered to takeoff into a headwind, because through the air you are going say 100 knots at takeoff, but you are only going 90knots over the ground and therefore not traveling as far to get up to 100knts airspeed and therefore not having as long a takeoff distance.

Also, a plane does NOT have to be at maximum power to takeoff, we do it all the time to save the aircraft turbines; its called a reduced power takeoff. So basically it is all about airflow over the wings, not how fast the wheels are moving that determines if a plane will take off. I could go into a big aerodynamics discussion, but it sounds like everyone is sick of this thread as as, so I hope this helps w/ the discussion, and has put some misunderstandings to rest. I guess I put about $2.00 in istead of 2 cents, sorry about that.