[MichaelP]

Depends on the aeroplane you fly.
Cherokee 140, look near to where you are.

In a Cessna 152 once, crossing the mountains late one afternoon, I calculated my glide as we flew on, could I make it to Nelson? To Castlegar?
Over water, and over mountains this can lead to an awareness, and from this a plan for if something goes wrong.

Eight miles north of Pitt Meadows at 3,000 feet you can glide a Diamond DA20-C1 to the runway, but only if you fly at best glide speed. Fly at 65 you won’t make it, at 60 definitely not, 71-73 KIAS that will do nicely, be on the fast side if there’s a few knots headwind.

[Trent772]

So when you ice up, stall at night and probably enter a spin, does that affect the glide ratio ?

[profchrisreed]

In the glider I used to own it was noticeable. Best glide 50 kt @125 feet per minute sink rate. Min sink 45kt @ 100 fpm sink rate. From 2000 ft that's 4 minutes extra airborne.

I've probably done the sums wrong, but I calculate that you'd go 13.3 nm at 50kts from 2000' (16 minutes) but 15nm at 45. (20 minutes). That would make 45kts your best glide speed, wouldn't it?

Chris' numbers may be slightly incorrect, 1.25 kts down at 50kts is 40:1 but 1.00 kts down at 45 is 45:1 so the better glide for those two points is at 45.

My glider has a best glideof 60:1 at 54 knots giving 90 ft per min sink and min sink at 41 and 79 ft per min sink.
At best glide from 2000 ft I'd get 20 nm taking 22 minutes and at min sink a mere 17.3 miles, taking 25 minutes.

I obviously got the airspeed wrong (From memory, and one rarely flies min sink). But the comparative sink rates are close to the actual performance.

One or two posters are using best glide in a different sense from the way it's used in gliding - we calculate it from the polar drag curve, and it's the speed for best distance through the air. Best distance over the ground is roughly the + half the headwind, but in practice your glide computer tells you

[AfricanEagle]

In the middle of the ocean, dead engine, trim all the way back and you'll spend the most time in the air before touching the water. You'll earn that little extra time for mayday calls and identification.

Overland, normally best glide, but speed as required to reach your chosen spot.

[Paul_Sengupta]

Most important is the need to increase the speed above best glide when gliding into wind.

And if gliding with the wind, you might want to slow it down towards best endurance.

trim all the way back

Does this work with most/all aeroplanes or just with the Cessna 172?

[defcribed]

Does this work with most/all aeroplanes or just with the Cessna 172?

Be nice if it did.....

The trim simply sets the speed the aircraft will fly at if the control column is released. So it'd be nice if with zero thrust full aft trim gave you a speed just above the stall and full forward trim gave you a speed just under VNE.

[flybymike]

The Rallye/Koliber is famously referred to as “the tin parachute”

[KeithM]

The Rallye/Koliber is famously referred to as “the tin parachute”

Is that because the engines have often failed?