I've got one of these at the airport. Had it in a box for almost 40
years and it still works! Too bad I don't have the space, battery
power, or weight allowance to mount it...

http://www.aviation-dream.com/images...21_Horizon.jpg
http://www.aviation-dream.com/images/Alb_inst/130621_Horizon.jpg

On 4/21/2015 7:55 AM, wrote:
On Monday, April 20, 2015 at 11:43:17 PM UTC-5, wrote:
WARNING: SIDETRACK--TANGENT--WAY OFF COURSE HERE

Whoops, I was in error. I labelled my fingers with "left" and "right" and flew it through with my hand again. Postively-loaded case, wings-level, inverted flight-- you won't be there for long, but if you try to keep the turn rate indicator needle centered, you'll give inputs that tend to roll the glider back to inverted wings-level flight after any deviation. Maybe not such a great thing. Negatively-loaded case-- if you move the stick against the direction of any indicated turn, you'll tend to roll toward a steeper bank angle. Sustained negatively-loaded flight would theoretically be possible by moving the stick in the same direction as any indicated turn-- just like one does when flying inverted visually. Obviously this is all theoretical.

For the most cases in cloud I don't think it's ending up in genuine aerobatic scenarios that the main concern. It's losing control of the pitch phugoid. A rapid increase in bank angle can put you through the redline long before the bank angle reaches sixty degrees. Likewise, a rapid decrease in bank angle during high-speed flight can pitch you up into the start of a loop if you don't react to the decreasing trend of the airspeed needle fast enough.

So yes, I absolutely agree that an artificial horizon is the best way to go. I guess that I've had enough exposure to what is possible with just a turn rate indicator, that I have a hard time believing that an artificial horizon wouldn't give the average pilot a good fighting chance without all sorts of special training. But, that's just me. I suppose the statistics say otherwise.

I'm sure a pilot with Chukar's experience would have done very well with either an artificial horizon or a turn rate indicator.

And I still like the idea of the redundancy provided by a simple, self-contained instrument that will power up in just a few seconds regardless of the aircraft's attitude and flight path. It seems like a good thing to have if the only other other thing one has is something that is built into a vario system.

By the way, an older generation of this same instrument needed to be flown for several seconds in wings-level flight during a calibration phase immediately after the initial start-up. I think they've made a great improvement in modifying the design to eliminate this.

Thanks much for all the various comments so far. It's a topic that I find quite interesting.

S

--
Dan Marotta