Lancair crash at SnF

tman inv@lid wrote in
:

Hold on while I try to correct some nits in what Bertie said and see
what happens

Bertie the Bunyip wrote:
Nope, the wind is going to help you in almost every way if you're
turning back.
[ many good points supporting this assertion, but... ]
also, your best LD speed is going to occur at a lower
airspeed,
Well, technically, your best LD speed is related to angle of attack,
and
not the groundspeed, so that won't change. Your best glide speed
certainly will be less...

OK, not the LD, you're right. but your best glide speed is realted to
your ground speed. To take an extreme example to illustrate this point,
imagine that your published best glide is 70 and you're trying to glide
into a 70 knot headwind. You're going nowhere. Increase your speed and
you will make headway.
In the tailwind scenario, your best glide distance over the ground will
be better at a lower speed than published. the stronger the wind, the
lower the speed required until you arive at your min sink speed.

There is no inertia involved in making a downwind turn. None.

Here's why I wonder about that. Let's suppose 65 KAS before and after
a
180 turn from a 10 KT headwind. OK, before the turn, your groundspeed
is 55KTS and after the turn your groundspeed is 75KTS. Your intertial
frame of reference is tied to the g/speed, not the a/speed. So -- the
kinetic energy of the aircraft and contents is about 33% higher
(75/55)^2. That energy is only going to come from one place with no
power -- trading in altitude (potential energy) for kinetic energy.

Nope, your inertial frame of reference owes nothing to the ground
whatsoever. None. Zero, nil zilch zippo. You ar entirely a creature of
the air and owe nothing to the ground whatsoever ( except in the
vertical, of course) The earth simply isn't that important in the bigger
scheme of things! If it were, you'd have trouble making left or right
hand tunrs in your car....


Bertie