Emergency instrumentation for cloud encounters

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

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

How do you guys avoid midairs when climbing in cloud? Does everyone circle left? I can't see even Flarm saving you.

On Tue, 21 Apr 2015 18:55:53 -0700, mark821ac wrote:

How do you guys avoid midairs when climbing in cloud? Does everyone
circle left? I can't see even Flarm saving you.

1) FLARM still works in cloud, so when you're close under one with no
gliders in sight but FLARM shows a glider above you, that is a
pretty good clue.

2) You should make a radio call on the XC/cloud flying frequency[1]
giving your intentions and position. Anybody else who is nearby
should respond with their details. If FLARM shows a glider above
you in cloud, frankly you're an idiot if you don't make that call
before switching on the T&B etc.

3) Clouds are much bigger than gliders so the chances of a collision
are relatively low (the big sky theory of collision risk): its
your choice whether you take that risk or stay out of cloud.

[1] In the UK 130.4 MHz is reserved for XC message passing and cloud
flying. I don't know if other countries have similar arrangements.


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

With all due respect to the poster below who argues the big sky theory applies to clouds (or anywhere for that matter). While not a highest time pilot, I have multiple thousands of hours between gliders, airplanes and helicopters I have actually swapped paint once with another aircraft and have at least 10 near collisions (20 feet or less of separation). Three times were while ATC was providing separation! One time is a story in itself and only a miracle/angel kept it from being a tragedy that would have killed 110 people (this one was on take off, same controller cleared two aircraft to fly into each other). I am not a big fan of the big sky theory, I frankly think it is as out dated as Flat earth.



On Wednesday, April 22, 2015 at 5:16:31 AM UTC-7, Martin Gregorie wrote:
3) Clouds are much bigger than gliders so the chances of a collision
are relatively low (the big sky theory of collision risk): its
your choice whether you take that risk or stay out of cloud.

[1] In the UK 130.4 MHz is reserved for XC message passing and cloud
flying. I don't know if other countries have similar arrangements.


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