John Miller wrote:
...I am just requesting IFLY take the GPS forward speed and descent rate and present the CURRENT glide ratio on the screen so the pilot can adjist pitch to maximize the glide ratio realtime.
Aha! Let's see if I have that right. You're asking for the "CURRENT glide ratio," right? That's not a glide ring, but a numerical statement, like "9:1" or "42:1"--yes? If so, then I agree: I'd like it, too. it needs only a simple "Glide Ratio" instrument. And it doesn't seem like difficult coding.
We already have a "Vertical Speed" instrument--which I'd never installed because my airplane has a barometric VSI that is more accurate and doesn't need electricity. (I've just added "Vert. Speed" now on my iPhone to see what it does for me.)
A "Glide Ratio" instrument would combine the Vertical Speed and the Ground Speed instruments to display the descent/ascent ratio. That should be very simple coding, because iFly already uses the two data streams, and combining them for the ratio should be dead simple coding. (Really! Copy one of those two speed instruments, add the formula, and change to the new Instrument name.)
So I join you in requesting a new Glide Ratio instrument for the very next iFlyGPS upgrade.
Going from glide RATIO to glide RING--the ideal goal--would be a lot more complicated, both in the coding and the computing power required. It would need to factor in the aircraft's preset glide ratio, the height AGL, and the surrounding terrain. And it would need to display the constantly changing "glide ring" over the map. Adding wind to that would be lovely; but as you pointed out, more difficult. (But probably not as difficult in iFly as in some other GPS apps because it already can display wind speed at various altitudes (1500 ft, 3k, and on up in 3k increments), in the Hi-Res Winds Aloft feature.)
While we're discussing the iFly instruments, I'd like to plead for a clear indication in the Inst Group lists of which instruments require additional hardware. Frankly, the current practice stinks! It's impossible to tell whether an instrument will work until you try it in the air.
Unless I'm missing something extraordinarily obvious. (And if I am, it isn't obvious enough.)