flight computer ergonomics and function

I'm curious.

After two successive near-midairs about 5 years ago, I installed PowerFlarm and a transponder that wouldn't deplete my battery during flight.

This required, due lack of panel space, that I give up my beloved ILEC S-10 flight computer (and its remote control). An Oudie IGC and and S-80 were recommended to replace it. The change has led to some conclusions about what flight computers should do in the cockpit.

1: Speed to fly
Flight computers all seem to calculate wind, and to be able to use the glider's polar. Not all use wind to revise STF.
It seems to me that we could use two rather different STF indications:
A: expected arrival altitude at next waypoint given polar, altitude, wind, and and optionally achieved mean L/D
B: best immediate speed for optimal L/D given polar, wind, and lift/sink over the last X seconds (user selectable)

(does any current flight computer offer these sorts of enhancements?)

2: Waypoint modification
Requiring the pilot to make an alphabetic search during flight to make a waypoint change is beyond stupid (it's a dangerous distraction).
- There are too many options for naming waypoints - recalling which name it was given is sometimes impossible.
- seldom are ICAO designations used, which aren't in any case easier to recall.
It seems to me that the best UI would have the ability to quickly limit the waypoint choices and swiftly move through the limited choices by spinning a knob or touch-pressing a knob-equivalent.
One is faced with either
- the need to modify one or more waypoints of a task
- the need to create a new task, the simplest of which is direct-to
Logical ways to create a limited set of waypoint choices include:
- distance (I think everybody offers this)
- direction (bearing, heading, or azimuth)
- distance & direction
- waypoints near current leg
- waypoints near current task

Do any current flight computers offer waypoint selection direction as well as distance?

Danl J

On Sunday, June 16, 2019 at 12:05:01 PM UTC-7, danlj wrote:
I'm curious.

After two successive near-midairs about 5 years ago, I installed PowerFlarm and a transponder that wouldn't deplete my battery during flight.

This required, due lack of panel space, that I give up my beloved ILEC S-10 flight computer (and its remote control). An Oudie IGC and and S-80 were recommended to replace it. The change has led to some conclusions about what flight computers should do in the cockpit.

1: Speed to fly
Flight computers all seem to calculate wind, and to be able to use the glider's polar. Not all use wind to revise STF.
It seems to me that we could use two rather different STF indications:
A: expected arrival altitude at next waypoint given polar, altitude, wind, and and optionally achieved mean L/D
B: best immediate speed for optimal L/D given polar, wind, and lift/sink over the last X seconds (user selectable)

(does any current flight computer offer these sorts of enhancements?)

2: Waypoint modification
Requiring the pilot to make an alphabetic search during flight to make a waypoint change is beyond stupid (it's a dangerous distraction).
- There are too many options for naming waypoints - recalling which name it was given is sometimes impossible.
- seldom are ICAO designations used, which aren't in any case easier to recall.
It seems to me that the best UI would have the ability to quickly limit the waypoint choices and swiftly move through the limited choices by spinning a knob or touch-pressing a knob-equivalent.
One is faced with either
- the need to modify one or more waypoints of a task
- the need to create a new task, the simplest of which is direct-to
Logical ways to create a limited set of waypoint choices include:
- distance (I think everybody offers this)
- direction (bearing, heading, or azimuth)
- distance & direction
- waypoints near current leg
- waypoints near current task

Do any current flight computers offer waypoint selection direction as well as distance?

Danl J

XCSoar on an OpenVario, But you have to build and maintain it yourself.

Tophat, which is based on XCsoar but with a different user interface, is all about ergonomics. (Thank you Robert Dunning!) It shows you the arrival altitude at nearby airports and landable points, right on the moving map. And you can tap on any waypoint and then tap "go to" and it becomes your new destination that it guides you to. That's handy if you get low and need to divert towards a safe landing point. If you later want to resume the original task, tap the nav bar and then tap "resume task".

And if you want to edit the task and choose an arbitrary waypoint, you can have it order the waypoints by nearest distance to your current location, or by highest arrival altitude, or alphabetically.

And talking about ergonomics, you can choose the hardware device among many possible - just about anything that runs Android can run Tophat (or XCsoar). I use an old Nook e-reader because the screen is large (6 inches) and the contrast of the e-ink type screen is not affected by direct sunshine. I've arranged for it to communicate with the FLARM but that took some hardware hacking.

BTW the STF does not vary with the wind, unless it's a survival glide to a landing.

SeeYou Mobile.

Your exsisting S80 and Oudie does all you require, have you read the manuals?

On Sun, 16 Jun 2019 12:04:58 -0700, danlj wrote:

Do any current flight computers offer waypoint selection direction as
well as distance?

Add LK8000 to the list. It shows the next turnpoint in the declared task
in the top left cornet. Tapping it cycles through the declared turnpoints
in task sequence, followed by HOME and the two closest landouts to your
current position.

Each item in the list automatically becomes the next selected TP when it
is displayed, so just stop tapping when your next destination is shown.


--
Martin | martin at
Gregorie | gregorie dot org

Yes.
Just a matter of learning the new stuff. The old isn't particularly great, just familiar.
Jim

On Sunday, June 16, 2019 at 2:05:01 PM UTC-5, danlj wrote:
I'm curious.

After two successive near-midairs about 5 years ago, I installed PowerFlarm and a transponder that wouldn't deplete my battery during flight.

This required, due lack of panel space, that I give up my beloved ILEC S-10 flight computer (and its remote control). An Oudie IGC and and S-80 were recommended to replace it. The change has led to some conclusions about what flight computers should do in the cockpit.

1: Speed to fly
Flight computers all seem to calculate wind, and to be able to use the glider's polar. Not all use wind to revise STF.
It seems to me that we could use two rather different STF indications:
A: expected arrival altitude at next waypoint given polar, altitude, wind, and and optionally achieved mean L/D
B: best immediate speed for optimal L/D given polar, wind, and lift/sink over the last X seconds (user selectable)

(does any current flight computer offer these sorts of enhancements?)

2: Waypoint modification
Requiring the pilot to make an alphabetic search during flight to make a waypoint change is beyond stupid (it's a dangerous distraction).
- There are too many options for naming waypoints - recalling which name it was given is sometimes impossible.
- seldom are ICAO designations used, which aren't in any case easier to recall.
It seems to me that the best UI would have the ability to quickly limit the waypoint choices and swiftly move through the limited choices by spinning a knob or touch-pressing a knob-equivalent.
One is faced with either
- the need to modify one or more waypoints of a task
- the need to create a new task, the simplest of which is direct-to
Logical ways to create a limited set of waypoint choices include:
- distance (I think everybody offers this)
- direction (bearing, heading, or azimuth)
- distance & direction
- waypoints near current leg
- waypoints near current task

Do any current flight computers offer waypoint selection direction as well as distance?

Danl J

Comments below force a response.
1: the most efficient calibrated airspeed for progress over the ground DOES vary with the wind. A published rule of thumb is with a headwind, add 1/3 the headwind component to best glide; with a tailwind, fly at minimum sink.
Jean Marie Clement has created a beautiful graph showing that the most efficient CAS against headwind is a curve -- it looks like it's an hyperbola. It's reproduced on page 51 of Brigliadoris' Competing in Gliders.

2: The Oudie IGC manual is quite clear that ONLY polar and pre-set MacCready are used in calculating speed to fly and arrival altitude. Wind is specifically not used in their calculation, and you can of course set your MacCready to the mean climb in the last thermal if you like.

The S8x manual does not indicate whether current lift/sink is used to modify the instant STF arrows indication, nor whether wind is taken into account.. The STF *is* based on the next waypoint, polar, and (I think) MacCready. I haven't used this, and will reconfigure my S80 now that I've updated the firmware and watch its behavior.

3: Does anyone on this forum actually ever do the research before replying? Just curious. The B/S ratio applies to more than thermals...

While Oudie does not take account of wind in determining STF it most definitely does in determining arrival height.

Wind affects STF to reach a fixed point on the ground as high as possible after your last climb. However it does not change STF for best progress on task - fly Mcready and accept what the wind does to your ground speed.

"The S8x manual does not indicate whether current lift/sink is used to modify the instant STF arrows indication, nor whether wind is taken into account. The STF *is* based on the next waypoint, polar, and (I think) MacCready."

Lift/sink does drive the speed up slow down arrows. Wind does not, nor does the next waypoint. As well as polar and Mcready it also considers wing loading. When changing Mcready ballast or bug settings LX devices tell you the zero lift figures for Mcrwady STF and glide ratio.

By the way, if you want to look for a waypoint in a particular direction on your Oudie drag your finger in that direction on the screen - sort on any column heading by touching it, touch the wp you want and goto. But you surely know all this.