Lancair crash at SnF

WingFlaps schrieb:

A direction change in a
plane is always due to acceleration (and that means more drag). That's
Newtonian physics.

Right.

You go from up wind direction (takeoff is usually
up wind) to turn in the wind direction to land down wind. There's an
acceleration, it is a change in _velocity_

Wrong.

it creates drag, it costs
height and that's the important bit. Now do you understand -TURNS are
not free,

Right.

Your're mixing up two completely different things. Of course, turns are
never "free". They cost energy due to higher drag, resulting from higher
speed, higher wingload and control deflection.

*But*: It absolutely doesn't matter whether you turn from headwind into
tailwind or vice versa. Your airspeed does *not* change. (Of course the
vector does, but not its magnitude.) Your groundspeed changes, but
that's not relevant. Your sentence "Now we add in the energy losses from
having to accelerate with the wind" can only be interpreted that you
think groundspeed would matter because you somehow had to "acceleerate"
to catch up with the wind speed when turning from head to tail wind.
Which is utter nonsense, Newtonianly spoken.

On Apr 25, 11:23*pm, Stefan wrote:
WingFlaps schrieb:

A direction change in a
plane is always due to acceleration (and that means more drag). That's
Newtonian physics.

Right.

Now we are at first base!


You go from up wind direction (takeoff is usually
up wind) to turn in the wind direction to land down wind. There's an
acceleration, it is a change in _velocity_

Wrong.

I see the problem. You don't know what velocity is. It's a VECTOR. It
changes when you turn. If you don't understand this there's not much
point talking about anything that involves physics....

Cheers

WingFlaps schrieb:

I see the problem. You don't know what velocity is. It's a VECTOR. It
changes when you turn. If you don't understand this there's not much
point talking about anything that involves physics....

Actually, I know an awful lot about physics.

In everyday's language, the word velocity stands for the _magnitude_ of
the vector. Now if you want me to realise outside some technical or
scientific environment that you use the word velocity in the vector
sense, you better say so explicitely. Still easier would be to say
"direction".

On Apr 26, 12:12*am, Stefan wrote:
WingFlaps schrieb:

I see the problem. You don't know what velocity is. It's a VECTOR. It
changes when you turn. *If you don't understand this there's not much
point talking about anything that involves physics....

Actually, I know an awful lot about physics.


So much that you mix up speed and velocity? LOL!

In everyday's language, the word velocity stands for the _magnitude_ of
the vector.

Nope. Not even at high school. The magnitude is "speed".

Now if you want me to realise outside some technical or
scientific environment that you use the word velocity in the vector
sense, you better say so explicitely.

Gosh, this isn't a technical forum? Was my post not including
"technical" terms like acceleration?

Still easier would be to say
"direction".

What does "flying with the wind" imply to you, a direction or a speed?
I'd say the former but I'm only a native English speaker.

Cheers

WingFlaps schrieb:

In everyday's language, the word velocity stands for the _magnitude_ of
the vector.

Nope. Not even at high school. The magnitude is "speed".

Maybe where you live. Not where I live.

On Apr 26, 12:57*am, Stefan wrote:
WingFlaps schrieb:

In everyday's language, the word velocity stands for the _magnitude_ of
the vector.

Nope. Not even at high school. The magnitude is "speed".

Maybe where you live. Not where I live.

BS. This is stated in any basic physics text book -even Wiki knows it:

"In physics...The scalar absolute value (magnitude) of velocity is
speed."

Cheers

WingFlaps schrieb:

In everyday's language, the word velocity stands for the _magnitude_ of
the vector.

Nope. Not even at high school. The magnitude is "speed".

Maybe where you live. Not where I live.

BS. This is stated in any basic physics text book -even Wiki knows it:

"In physics...The scalar absolute value (magnitude) of velocity is
speed."

What part of "everyday's language" wasn't clear?

On Apr 25, 7:11 am, WingFlaps wrote:

"In physics...The scalar absolute value (magnitude) of velocity is
speed."

Cheers

But it's relative to space, not the earth, as I posted earlier.
Earth pulls straight down, nothing more. Do this, as we have done many
times: Go out and fly on a day when the upper winds are at 30 or 40
knots and get under the hood, do 30 degree banked turns, maintaining a
constant altitude and power setting, and see if the airspeed changes.
Got to be done over flat land, BTW. Any orographic lift will screw up
the altitude. You won't see any performance changes, but the
airplane's flight path over the ground sure isn't circular. Try 45
degree banked turns. Try it in a glide. See if you can prove me wrong.

Dan

On Fri, 25 Apr 2008 05:00:45 -0700 (PDT), WingFlaps wrote:

I see the problem. You don't know what velocity is. It's a VECTOR. It
changes when you turn. If you don't understand this there's not much
point talking about anything that involves physics....

Talk about thick... you don't even have the slightest clue what velocity
really is.

*snicker*

You've been making a supreme fool of yourself all this time, puffing
your chest and calling other people stupid in your usual self
aggrandizing way. Read this and weep, bitch. Maybe some day you'll learn
to not be such an arrogant jackass.
--
John

On Apr 25, 11:23*pm, Stefan wrote:
WingFlaps schrieb:

A direction change in a
plane is always due to acceleration (and that means more drag). That's
Newtonian physics.

Right.

You go from up wind direction (takeoff is usually
up wind) to turn in the wind direction to land down wind. There's an
acceleration, it is a change in _velocity_

Wrong.

it creates drag, it costs
height and that's the important bit. Now do you understand -TURNS are
not free,

Right.

Your're mixing up two completely different things. Of course, turns are
never "free". They cost energy due to higher drag, resulting from higher
speed, higher wingload and control deflection.

I'm not mixed up, You wanted to read something into what I wrote that
was not there and try to score some point I think Well you were wrong
and you still are. I never said airspeed did I?

One last time, as succinctly as I can: to change direction requires
more energy as extra drag = k.m.dV/dt. dV/dt is acceleration and that
is precisely the term I used. The aircraft does _accelerate_ into the
downwind direction. Airspeed may not change but _velocity_ sure as
hell does -'cos IT'S A VECTOR. Now, the energy needed for the change
in _velocity_ comes from the loss of height during the turn and that's
easy to calculate. It is much harder to estimate the extra drag loss
as this will depend on pilot skill and aircraft design. I hope you
finally understand, cos I'm really starting to find it tiresome trying
to explain to you some basic physics which you seem intent on mis-
interpreting.

I'll give you this last post, any continuance along your previous
lines of putting erroneous words into my mouth I will take as your
being a troll...

Cheers