Mailing List lml@lancaironline.net Message #54130
From: Keith Smith <keith.smith@gmail.com>
Sender: <marv@lancaironline.net>
Subject: off topic: RC gliders doing 399mph GS
Date: Wed, 06 Jan 2010 16:15:37 -0500
To: <lml@lancaironline.net>
I post this here only because Lancair folks tend to be interested in
speed and performance.

Picture a radio controlled glider, flying around in slope lift on the
traditional 'front' side of the mountain.  Historically, speed records
were set by climbing as high as possible, pointing straight down, and
reaching terminal velocity, at best.  This is how it was for many
years until a pilot, Joe Wurts, accidentally flew onto the 'back' side
of the hill where glider pilots were "never supposed to go."  He
popped back out of there going faster than he came in.

Dynamic soaring for RC gliders was born (stolen from the albatross,
which has been doing a form of this for quite some time).  Years
later, the speed records have fallen, 200mph, 300mph, and just a few
weeks ago, a glider hit 399mph ground speed.  Front side wind speeds
were measured at 45-50mph, meaning that, at certain times, the plane
was seeing close to 450mph over the wings.

If that doesn't blow your mind, imagine completing 2 180 degree turns
(picture a racetrack hold) at that speed, inside _3 seconds_.

The g-loading is obscene....small wonder that for many years, gliders
not built for the task (there were none, of course) turned to confetti
during some of these turns. Very early on (in the 200mph days),
someone installed a g-meter, good for up to 40g in their plane.  After
a pretty quick run, they landed and pulled out the unit to check the
peak reading. It read '40', the maximum it could capture.

I personally flew my airplane to 165mph (the only time I had it
measured with a radar gun, anyway), and that was plenty for me. I can
only imagine the reflexes needed to fly a tight profile, in and out of
a 45mph shear layer at 350-400mph, all the time, keeping the plane in
visual range.

I've been out of the scene ever since I left Northern California for
New Jersey, but while I was there, it was a life changing experience
doing that kind of flying.  The sound that a glider with a 90-120"
wingspan makes when it blasts through the air at those speeds is not
unlike a jet. You feel it in your gut when it goes by. The sounds on
the video do not do it justice.

When you watch the video, please believe me when I say that the plane
does not have an engine:
http://vimeo.com/8356047

That video is actually TOO fast to really appreciate or even
understand what's going on.  There are plenty of slower vids on
youtube, though.

After all these years, it still amazes me that it's so easy to extract
this much energy from the air.
Subscribe (FEED) Subscribe (DIGEST) Subscribe (INDEX) Unsubscribe Mail to Listmaster