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Old 01-17-2004 | 02:00 AM
  #23  
Flydenfeld
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From: E. Northport, NY
Default RE: WIND!!

Azseattle, here's another tid-bit that might help with winds and what people are talking about here...

Lets say there is no wind, and your plane's stall speed is 15 mph. Well, you apply throttle, and once you are moving along the ground at 15 mph or better, you can lift off!

Now lets say there is a 10 mph from the north, heading south. So, you put your plane on the ground facing the wind, north. Heyyyy, check it out! Your plane is sitting still, but the wing thinks its already going at 10 mph!!! Now you add power, your plane gets up to 5 mph, and you can lift off!!! The wing is seeing 15 mph, but YOU are seeing 5mph. In other words, the AIRSPEED is 15 mph, but the GROUNDSPEED is 5 mph.

See the advantage of taking off and landing into the wind?

Taking this a step further, up till now you may have grown accustomed to eyeballing the appropriate speed to land. Basically you are judging the approach speed by ground speed, not airspeed. Well, lets say again your stall speed is 15 mph. Using the 30% rule you decide to use an approach speed 20 mph. Fine, you come in at 20 mph, come over the landing area, reduce power, flare, land. Niiiccccce.

Sooo, now on a windy day you try to replicate this speed you are used to seeing. But you are landing into a 20 mph wind (what we call headwind). You find you need more power to get to the 20 mph groundspeed you are used to seeing. BUT, your wing could care less about groundspeed, its only interested in AIRSPEED, which is now 40 mph! As a result, the controls are more responsive, and you are getting bounced around.

But if you apply what you know now about airspeed vs. groundspeed, you can learn to come in at slower groundspeeds while your plane is at the appropriate airspeed. Taking advantage of the "headwind" will let you land slower and more precisely.