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Old October 4th 07, 05:47 PM posted to rec.aviation.piloting
Le Chaud Lapin
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Posts: 291
Default Backwash Causes Lift?

On Oct 4, 6:39 am, Tina wrote:
Still waiting for the conservation of momentum derivation. My husband,
also trained as an engineer, casually remarked he didn't think you
could get from Newton's First Law to the that confirms my memory,
but we are both willing to have that belief rebutted.


My apologies for broaching the subject. Frankly, I would rather save
it for the physicists.

He also pointed out that how a CFI might explain how a VOR works would
not satisfy an engineer. For that matter, the physics of flight as
explained to a student pilot would not satisfy someone who might be
interested in designing, as opposed to flying, an airplane, but I
don't think the manuals you are looking at are in error.


If the manuals are in error, then they are in error. If the manual
issues a disclaimer, saying something, like, "this is not really what
is happening, but this will suffice for us..." that would be ok.
That's not what's happening. The manual mentions things like
Bernoulli, Newtons laws of motion. It even uses vector notation for a
few of the formula's. When one gets that close to the merchandise,
they need to purchase it.

I would point
out that each field has its own language, and you denying the
conventions used in aviation -- drag, lift and so on -- demonstrates
an unbecoming trait for a student, and even a worse one for an
employee. You may want to rething that attitude if you use it in real
life.


There is a difference between convention and errononeous information.
I never discounted drag, lift, or so on...I discounted the
explanations given some of my flight education materials. If it's
wrong, it's wrong. If someone reading it gets comfort from thinking
they understand, or whatever, that's fine for that person. But the
writers of those manuals should know that their audience is broad, and
should not publish erroneous information (after they know that it is
erroneous). There is gross difference between explaining something in
simple terms and being correct, versus explaining something in
moderately-difficult terms, and being incorrect.
I could probably explain VOR to a 10-year-old, without ever mentioning
things like counters, angular frequency, anisotropic radiation,
frequency bands, sub-carriers, convolution, etc....and my explanation
would still be correct.

"When you drink from a straw, there is no suction force."

-Le Chaud Lapin-