In the anshu aerospace-about flight-Flight is a relatively simple and widely studied phenomenon. As
surprising as it may sound, though, it is more often than not
misunderstood. For example, most descriptions of the physics of lift
fixate on the shape of the wing (i.e., airfoil) as the key factor in
understanding lift. The wings in these descriptions have a bulge on the
top so that the air must travel farther over the top than under the wing.
Yet we all know that wings fly quite well upside down, where the
shape of the wing is inverted. This is demonstrated by the
Thunderbirds in Figure , with wings of almost no thickness at all.
To cover for this paradox, we sometimes see a description for inverted
flight that is different than for normal flight. In reality, the shape of the
wing has little to do with how lift is generated, and any description
that relies on the shape of the wing is misleading at best. This assertion
will be discussed in detail in Chapter 1. It should be noted that the
shape of the wing does has everything to do with the efficiency of the
wing at cruise speeds and with stall characteristics.
Let us look at three examples of successful
wings that clearly violate the descriptions that
rely on the shape of the wing as the basis of lift.
The first example is a very old design. Figure
shows a photograph of a Curtis 1911 Model
D type IV pusher. Clearly, the air travels the
same distance over the top and under the bottom
of the wing. Yet this airplane flew and was
the second airplane purchased by the U.S.
Army in 1911.