Emergency instrumentation for cloud encounters

I'd buy one of those turn coordinators if someone would buy my TruTrac...

On 4/20/2015 11:55 AM, wrote:
why not have one of these:

http://store-vllhq23n.mybigcommerce....-in-enclosure/
http://store-vllhq23n.mybigcommerce....dback-systems/

This is portable and powers up in seconds in any attitude or flight condition.

Contrary to the label this is a pure yaw rate indicator, plus a slip-skid indicator. It does not behave quite like a "turn coordinator".

There are of course more comprehensive ways to go, but this is a whole lot better than nothing. I'm speaking specifically to those pilots who are currently flying with nothing. We all know that in some circles, partial-panel flying of sailplanes in clouds is, or used to be, considered a perfectly normal thing to do.

Some dual practice under the hood would be extremely beneficial of course. It's crucial to respond to the direction the ASI needle is trending, more than to the actual airspeed indication. This doesn't come intuitively.

Likewise this particular instrument has in my opinion a significant possibility of being read backwards. The fixed aircraft symbol on the front of the device has no significance and in my opinion should be covered up with a blank label, or with some design of the pilot's own creation, so the pilot is not tempted to interpret the instrument like an artificial horizon. which would be backwards. The LED's represent the wingtips of an imaginary aircraft which tips left and right to indicate turning-- not a horizon line.

But I can attest that it works.

The compass-on-a-southerly-heading trick works too, as discussed in a related thread recently. ("In wave, in blue hole at cloud level, hole closes, in IMC, then what?"). But you are utterly and thoroughly hosed if you let the compass swing out of the "sweet spot" that extends for about 45 to 60 degrees on either side of the the due magnetic "south" indication. You had better be established and stabilized on this heading before losing visibility. I'm speaking for mid-latitudes in the northern hemisphere here.

I once had an experience where I was unable to hold heading in a cumulus cloud using GPS + rudimentary turn rate indicator. I was able to keep out of a spiral dive, but not able to hold heading well enough to make good progress out of the cloud. However, I was able to keep the turn rate low enough that I could successfully "capture" a southerly heading and then I switched over to using the compass as my primary instrument, and I was able to hold heading indefinitely. On a southerly heading, the compass actually did a prompter and better job of signalling small heading deviations, than did the rudimentary turn rate indicator. It would be pretty much suicidal to try this without having the turn rate indicator to fall back on in case a spiral dive started to develop due to a strong jolt of turbulence or a wrong control input on the pilot's part.

In thermal conditions, there's no excuse for accidentally getting into clouds, and an untrained pilot is likely to be in a world of hurt. But in the (sometimes) smoother wave environment, I think there's a real case to be made for routinely carrying a turn rate indicator for emergency use. And a freshly packed parachute of course.

S

--
Dan Marotta

On Monday, April 20, 2015 at 4:34:11 PM UTC-7, Dan Marotta wrote:

I'd buy one of those turn coordinators if someone would buy my
TruTrac...

Dan Marotta

I'll keep my TruTrac. It doesn't have pitch, but with instrument training, it has what it takes with a familiar AH like display to keep wings level or to do a turn. I leave it off unless in "the vicinity" of clouds. When powered up, it "erects" in a couple of seconds, even in the middle of a steep turn. I'll add the Butterfly - redundancy.