Peter,
Todd wrote:
Pete, in your reply above, you did the same thing Roger did,
(and what I often do too,) you equated the vertical
component of aerodynamic force to "lift."
[zap]
The real issue here is whether lift changes according to airspeed. The
generic idea of lift (as in, the force that keeps airplanes aloft) versus
the specific physics definition of lift is inconsequential in that
context,
and not one I feel is worth nitpicking over.
It is *exactly* worth discussing and it is not nitpicking. Lift as DEFINED
is completely different to the force pointing upwards and there are many
examples where they all completely different; some example: spins, steep
turns, a plane climbing vertically, a flat spin, the F-18 slow pass...
OK, quick question: how much 'lift' (your definition) is an aircraft
producing in a 45 degree bank? Equal to the weight? If so, why does my
stall speed increase? Nitpicking? Well this nitpicking kills a lot of
pilots including very experienced ones.
How would you explain to a pilot that even though lift equals weight in a
steep turn (your definition), the stall speed increases?
Hilton
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