PowerFlarm Warnings Display Comparison

On Friday, November 21, 2014 3:30:50 PM UTC-8, Sean Fidler wrote:
Great stuff! Thanks!!!

Slightly of topic but I wonder why we are still using clock to tell directions. Yeah it sounds cool but is it really necessary?
In the age of digital clocks, it takes time for most people to interpret it.. Case in point is tow pilots. I noticed about 20% of tow pilots turning opposite direction when I say for example turn to 9 oclock instead of turn left. The rest take few long seconds to interpret.
How about front, back, left, right, front left, back right etc, similar to car GPS? Or 20 degrees left etc? Yeah I know its not perfect either and some people mix left and right as well, but maybe something to consider.

Ramy

If 12 o clock is at the nose, they'll be spinning circles until they run out of gas.

"Turn heading 230" is more specific.

On Friday, November 21, 2014 7:42:53 PM UTC-8, Ramy wrote:
On Friday, November 21, 2014 3:30:50 PM UTC-8, Sean Fidler wrote:
Great stuff! Thanks!!!

Slightly of topic but I wonder why we are still using clock to tell directions. Yeah it sounds cool but is it really necessary?
In the age of digital clocks, it takes time for most people to interpret it. Case in point is tow pilots. I noticed about 20% of tow pilots turning opposite direction when I say for example turn to 9 oclock instead of turn left. The rest take few long seconds to interpret.
How about front, back, left, right, front left, back right etc, similar to car GPS? Or 20 degrees left etc? Yeah I know its not perfect either and some people mix left and right as well, but maybe something to consider.

Ramy

I sort of agree. The first time I heard the lady my reaction was where is that. I had not looked at a hand clock for at least 15 years. But after some use it came back.

Richard
www.craggyaero.com

Today we use cell phones to tell time. The direction commands should be.

Traffic in your hand.
Traffic in your pocket.
Traffic by the toilet.
Traffic under the car seat.

Lane

At 08:36 22 November 2014, Richard wrote:
On Friday, November 21, 2014 7:42:53 PM UTC-8, Ramy wrote:
On Friday, November 21, 2014 3:30:50 PM UTC-8, Sean Fidler wrote:
Great stuff! Thanks!!!
=20
Slightly of topic but I wonder why we are still using clock to tell
direc=
tions. Yeah it sounds cool but is it really necessary?

Remember, if you're flying too slowly into a strong headwind in wave and
thus proceeding backwards over the surface of the earth, when Flarm calls a
conflict at 12 o'clock it's behind you....

On Saturday, November 22, 2014 4:15:04 AM UTC-6, Z Goudie wrote:
At 08:36 22 November 2014, Richard wrote:
On Friday, November 21, 2014 7:42:53 PM UTC-8, Ramy wrote:
On Friday, November 21, 2014 3:30:50 PM UTC-8, Sean Fidler wrote:
Great stuff! Thanks!!!
=20
Slightly of topic but I wonder why we are still using clock to tell
direc=
tions. Yeah it sounds cool but is it really necessary?

Remember, if you're flying too slowly into a strong headwind in wave and
thus proceeding backwards over the surface of the earth, when Flarm calls a
conflict at 12 o'clock it's behind you....

So true, but it's also making the beeping sound to indicate you are backing up, dead giveaway.
beep, beep, beep

Remember, if you're flying too slowly into a strong headwind in wave
and
thus proceeding backwards over the surface of the earth, when Flarm
calls
a conflict at 12 o'clock it's behind you....

More importantly, when it shows "on your left" it means "on your right" -
and that's not just a theoretical
nicety!

On Saturday, November 22, 2014 5:15:04 AM UTC-5, Z Goudie wrote:

Remember, if you're flying too slowly into a strong headwind in wave and
thus proceeding backwards over the surface of the earth, when Flarm calls a
conflict at 12 o'clock it's behind you....

So more generally, 12 o'clock on the Flarm warning circle aligns with bearing rather than heading?

On Saturday, November 22, 2014 10:03:18 PM UTC-5, son_of_flubber wrote:
On Saturday, November 22, 2014 5:15:04 AM UTC-5, Z Goudie wrote:

Remember, if you're flying too slowly into a strong headwind in wave and
thus proceeding backwards over the surface of the earth, when Flarm calls a
conflict at 12 o'clock it's behind you....

So more generally, 12 o'clock on the Flarm warning circle aligns with bearing rather than heading?

You are kidding, I hope.
UH

On Saturday, November 22, 2014 9:03:18 PM UTC-6, son_of_flubber wrote:
On Saturday, November 22, 2014 5:15:04 AM UTC-5, Z Goudie wrote:

Remember, if you're flying too slowly into a strong headwind in wave and
thus proceeding backwards over the surface of the earth, when Flarm calls a
conflict at 12 o'clock it's behind you....

So more generally, 12 o'clock on the Flarm warning circle aligns with bearing rather than heading?

OK, time for some basic FLARM theory:

FLARM uses GPS and pressure altitude exclusively; it has no heading input. So the warnings it sends are based on pressure altitude, GPS position and GPS track - and it assumes you are moving forward. It has no way of knowing which way your fuselage is pointing.

So FLARM warnings are aligned to your TRACK, not your HEADING. And in most cases, this is sufficient, as you are not trying to nail down a bearing to another glider within a few degrees - each clock sector is 30 degrees, remember.

That's why a FLARM display on a moving map (like an Oudie) is nice - it will be based on the GPS position of the other FLARM equipped gliders, so even if you are backing up in wave, it will show their true position relative to you (although, you will appear to be flying backwards on your Oudie!).

So, to summarize, the displayed BEARING to a FLARM target is referenced to your TRACK, not your HEADING, so if there is a lot of drift due to wind, you will have to compensate for it.

(Any FLARM-smarter guys out there, please correct me if I have got it wrong!)

Kirk
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