I saw a video of a small propeller plane hovering over the ground due to strong headwinds but then turns 180 degrees and flys away. I was trying to figure out if the plane shouldn't be stalling because at some point in the turn it doesn't have lift from the headwinds anymore and also doesn't have speed to produce the necessary lift (unlike a turn in a typical scenario with no such headwinds where the airplane has speed from its inertia) so my conclusion was that either the speed it slowly picked up during the turn was sufficient or I have a mistake in my understanding of physics.
$\begingroup$
$\endgroup$
10
-
5$\begingroup$ If you remove the ground from the scenario—and after all, the plane doesn't know or care how the ground is moving at some distance away—and operate in the rest frame of the air, the plane simply executed a U-turn, likely at near-constant speed. Does the confusion remain after considering this? $\endgroup$– ChemomechanicsCommented Aug 27, 2023 at 6:50
-
$\begingroup$ @Chemomechanics is that the correct way to think about it? If headwinds suddenly stopped to 0 would the plane be flying at the same airspeed immediately? $\endgroup$– salmoreCommented Aug 27, 2023 at 6:54
-
$\begingroup$ In rest frame of the air the plane as non zero headwind if and only if it has a non zero velocity in its normal direction. We can assume that this is always the case. Seems like you mix up that headwind which carries the plane with the wind that goes over the ground. Ignore the latter as the first comment has recommended. $\endgroup$– Kurt G.Commented Aug 27, 2023 at 8:44
-
$\begingroup$ @salmore, the air mass could never "suddenly stop to 0." Air has inertia too. $\endgroup$– Solomon SlowCommented Aug 27, 2023 at 9:28
-
1$\begingroup$ @salmore The scenario you're describing is known as a microburst, a localized downward air flow that spreads radially as it approaches the ground. An airplane flying at low altitude into a microburst first experiences a headwind. When it passes through the core of the burst, the wind suddenly reverses direction. The sudden loss of lift may cause loss of control and a crash. en.wikipedia.org/wiki/… $\endgroup$– John DotyCommented Aug 27, 2023 at 18:23
|
Show 5 more comments
1 Answer
$\begingroup$
$\endgroup$
2
The behavior of an airplane traveling through the air has only to do with its speed relative to the air, not its speed relative to the ground- as far as the airplane's wings are concerned. To see this, imagine the the plane is flying at 60 MPH through the air straight into a headwind of 60 MPH over the ground. Its net speed over the ground is zero yet it doesn't fall out of the sky because as far as the wings are concerned, it is moving through the air at 60 MPH.
answered Aug 27, 2023 at 17:47
-
$\begingroup$ This is obvious and isn't answering the question. $\endgroup$– salmoreCommented Aug 29, 2023 at 15:55
-
$\begingroup$ then I fail to see what exactly your question is. $\endgroup$ Commented Aug 29, 2023 at 16:13