Bill Daniels wrote:
"Ralph Jones" wrote in message
...
On Thu, 06 Dec 2007 16:25:30 -0700, Ralph Jones
wrote:

On Thu, 6 Dec 2007 15:28:23 -0700, "Bill Daniels"
bildan@comcast-dot-net wrote:

I was very pleased to see the advert in the December issue of "Soaring
Magazine".
See: www.safeflight.com

Does anybody know more about this device - especially the price?

Hope it works out. A design for an AoA indicator appeared in _Soaring_
twenty or thirty years ago, but it was really crude. IIRC, it had its
own separate pitot and static sources, and connected them across a
vertical, tapered tube similar to one side of a pellet vario. A solid
metal ball rode in the tube, its mass serving to sense acceleration,
and its vertical position gave a measure of AoA.

The vane types found on jets work splendidly, but they're mounted high
up on the airplane where people and vehicles don't bump into
them...the equivalent on a glider wouldn't last long!

I presume the Safeflight device uses the pitot/static/acceleration
principle...that should be relatively easy with contemporary sensor
technology and chips.

Oops, no, I see on the website that it uses a vane. That's likely to
be a problem...

rj

Note that they say the vane is removable. You would probably install it as
you would a TE probe just before flight and remove it just after landing.

Pity they don't say which sensor they use on the glider AOA instrument.
If its the type with 360 degree rotation, it could easily be using an
optical sensor (Grey encoded rotary position sensor or similar), in
which case the system could be quite robust and friction-free,
especially with a removable vane.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |