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**Bertie the Bunyip[_25_]** · April 25th 08, 12:58 AM posted to rec.aviation.piloting,rec.aviation.student

WingFlaps wrote in news:80a95935-4492-4d7d-95c1-
:

On Apr 25, 10:48*am, Stefan wrote:
WingFlaps schrieb:

Try reading the statement again, here it is:

"Now we add in the energy losses from having to accelerate with the
wind and to glide speed."

Now perhaps you would like to revise some physics and try to
critcise
it for us?

It's the "having to accelerate with the wind" part which is complete
BS
unless I completely misunderstand what you are trying to say.

The latter I think. The imposed accelerations associated with the
change in direction (from upwind to downwind) require control inputs
that add drag and increased energy loss (from drag).

To summarise your missed point, the pilot control inputs cost energy
that is not factored into simple glide/time analysis.

Nope, the wind is going to help you in almost every way if you're
turning back. Firstly, your climnb gradient will have improved from the
headwind, leaving you higher for a given distance from the field. Also,
your glide is going to be improved by the tailwind when you do turn
downwind. also, your best LD speed is going to occur at a lower
airspeed, which will give you a couple of extra seconds if you have the
presence of mind to take advantage of it. You'll probably be a little on
the slow side after having made the turn anyway, so that's a help there.
If there is any crosswind element to the wind, you have another plus if
you turn towards the wind. The x-wind will minimise the radius of the
manuevering turns you will have to make.
There is no inertia involved in making a downwind turn. None. What does
cause trouble during a climbout is twofold. the wind gradient can cause
trouble, as it will for any tailwind/climb situation because inertia
does play a role there, and two, the perceived acceleration to the
eyeball can cause the pilot to do some untoward things. That's how that
particular old wive's tale came about.
However, the gradient is also your friend in the turnback/tailwind on
approach situation. the decreasing tailwind will bump your airspeed up
on approach and cut your G/S as you descend back to the runway.
I'd consider a turnback with some headwind on takeoff and the calmer it
is the less consideration I'd give to that avenue, depending of course
on the other circumstances.

Bertie