ORIGINAL: cfircav8r
ORIGINAL: TimT2000
ORIGINAL: brad59
Highhorse is correct but only addresses an aircraft in a constant state. As a pilot of RC aircraft and full scale planes for many years I know that one can see obvious effects when you turn away from or into the wind. The factor not addressed is acceleration. An plane flying in a strong wind which quickly turns 'downwind'' will not suddenly accelerate into the new airflow (wind). Depending on variables such as mass and drag the plane will take some time to accelerate to the new speed. During this time there can be a loss of speed and a resultant loss of lift. It is usually easily corrected with elevator application but the effect is real. The same thing can happen in reverse which is why many planes will climb as they turn into the wind.
Yes, a plane does not care what direction the wind is going, but it does care about changes in airspeed/lift. Nearly all of us have taken off into a strong wind and felt the plane try to sink out when we turn downwind. It's not imagined.........
Brad
<div><span>Good job Brad, while highhourse is correct, it is not complete. Your post finished it. This problem with acceleration in the big planes (like the B-52)
can take some time. Even with our RC's on very windy days, you can see the acceleration when you yank it down wind. It does take time though.
A 200 ton object can not instantly go from 200mph to 220mph through a space, there is time involved.
Likewise turning into the wind does not magically dissipate the inertia,, it takes some time.</span></div><span>
Tim
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I'm sorry but what "new airflow" are you referring to? Gusting? In a steady wind there is only one airflow. When you change direction the inertia is seen in the different ground speeds. The speed changes you are referencing is relatable to ground speed not airspeed. If you want to maintain groundspeed then yes what you are saying is true, but air speed is in relation to the airmass and not the ground. The inertial changes seen at the A/C are the same with wind or without. These are acted upon by the turning componant of lift and are counteracted by the increased drag. when you add wind the inertia from the wind direction is directly translated into ground speed. When you go from a 20 knot tail wind to a 20 knot head wind you have a 40 knot reduction in ground speed, that is the inertia you keep referencing.
This is all very true,, I was just trying get the time point across. My powered parachute might show this the best because of the low airspeed (30mph).
If I turn down wind fast, (15mph wind) , it takes some time for the craft to get to the new 30mph airspeed (45mph ground speed) and I can loose
50 feet or so. We fly at 50 feet a lot so it isvery important to us. note: we make level turns in 0 wind, but it is hard to do in 15mph winds. Of course this
would never be felt in a 300,000lb jet going 300kts.
Tim