I find Climb Maximizer to be pretty useful. It appers
to work on the same basic principle as Tom describes
for Themi though I suspect each uses its own algorithm.
Having looked at the Themi, I personally find the blinking
lights to be a bit non-intuitive compared to the 'cut
soda can' display Winpilot uses to depict climb rate
around each turn, the arrow pointing to the strongest
lift and the beep when it's time to shallow your bank.
The beep is great because you can be looking in any
direction and still make use of the advice.

I know one person who installed a Themi and took it
out after finding it too hard to decipher. That's only
one example, so don't draw too much from it. Other
pilots seem to like theirs. It certainly doen't take
up any space if your panel is already full. On the
other hand WinPilot is also a full flight computer,
so if you're setting up a new panel there may be some
cost benefit.

One shortcoming for me is that you need to fly a complete
circle before climb maximizer can give any advice.
The first turn is often the most critical in terms
of centering - or leaving - a thermal. For that decision
you're on your own.

9B

At 14:30 27 January 2005, Thomas Knauff wrote:
First of all, I am a dealer for Themi in the USA.

Bernd Scheffel, the designer of Themi, came to our
gliderport several years
ago with his Themi device and installed it in our Duo
Discus. We flew
together for an hour or so, and I considered the device
as 'interesting.'

With my vast hours of thermalling experience, I had
developed certain
Pavlovian responses to bumps in the air and beeps of
the audio. I considered
my thermalling methods to be at least above average,
fully understanding the
typical turmoil of the thermal air-flow. I doubted
if Themi would be a
useful tool - at least for me or any experienced pilot.

One day, I decided to find out just what Themi was
capable of. I doggedly
followed the blinking lights and discovered to my amazement
that it was
unerringly correct. Often, my resposnes to bumps and
beeps would have been
different than Themi indicated.

One must understand Themi does not look out the window.
Using simple
variometer and GPS signals, it only tells the pilot
where the center of the
lift was as experienced during the last turn.

For this reason, I find Themi most valuable when there
are no clouds, or
iwhen low and disassociated from the clouds. At these
times, Themi is
invaluable.

Themi uses two bright LED lights to signal when to
steepen, shallow turns or
fly straight to the better lift. When the pilot is
centering correctly,
there are no light signals. No distracting audio, nothing
to distract the
pilot. There is no reason to look anywhere except outside
the glider,
observing conditions outside for visual clues and collision
avoidance.

The trend towards devices inside the cockpit which
can be distracting, and
often provide lots of 'interesting' information rather
than the few things a
pilot really needs to know is an important issue when
considering adding any
device to your cockpit.

More information about Themi can be found on our web
site.

Tom Knauff
Knauff & Grove Soaring Supplies
www.eglider.org