density and glide range

[baleares]

Am I right that glide range will be unaffected by a higher density altitude but that time in the air will be shorter ?

thanks!

[funfly]

Wow, that's got us thinking !

[thing]

I'm pretty dense, just threw myself out of the window, didn't glide far at all.

Would it be similar to the weight conundrum? I seem to remember that a heavier a/c will glide just as far as the same type but lighter but not take as long.

[Heston]

Or maybe more importantly, will the best glide speed in terms of IAS be the same or different at different density altitudes?


Mind you when the engine stops you will have more pressing things to worry about first.

[Piper.Classique]

You won't notice any difference in the real world.

[baleares]

(IMVHO)

I think that you always will glide at max L/D ratio which will not change with density.

Because there is less drag you will glide faster along the same glide slope: same range, less endurance.

But I am not sure!

[Genghis the Engineer]

It density altitude is greater, TAS is greater.

If (and it is a bit of an IF) best glide speed and L/D.max are fixed, then the OP is quite right - it'll be the same glide ratio at a higher true speed. So, same ratio, less time.

G

[baleares]

many thanks!

[AirborneAgain]

Am I right that glide range will be unaffected by a higher density altitude but that time in the air will be shorter ?

Yes and yes.

Best L/D ratio is obtained at a particular angle of attack. It does not depend on air density.

At higher density altitude you will have to fly faster to maintain lift at the best L/D angle of attack, thus sink rate will increase, while glide range will not.

(But note that only the true airspeed will increase. The indicated airspeed will stay the same.)