Glide Ratio

[mulro767]

I'd like to see ForeFlight add a glide distance calculator to the next software update.  Imagine just entering a glide ratio (12:1) in the settings, and once you start climbing a ring surrounding your airplane expands showing your glide distance based on zero winds. I think for situational awareness it would be a great tool as you could see immediately airports within safe gliding distance.  There would have to be a calculation of GPS altitude against a grid mora or AFE, but I think it could be done. If you like this idea, send them an email supporting it.  Also, urge ForeFlight to add a split screen similar to WingX Pro. Customer opinions matter there.

team@foreflight.com

[Stephen]

On 12/19/2011 at 2:20 PM, mulro767 said:

I'd like to see ForeFlight add a glide distance calculator to the next software update.  Imagine just entering a glide ratio (12:1) in the settings, and once you start climbing a ring surrounding your airplane expands showing your glide distance based on zero winds. I think for situational awareness it would be a great tool as you could see immediately airports within safe gliding distance.  There would have to be a calculation of GPS altitude against a grid mora or AFE, but I think it could be done. If you like this idea, send them an email supporting it.  Also, urge ForeFlight to add a split screen similar to WingX Pro. Customer opinions matter there.

 

team@foreflight.com

 

Zombie thread resurrection. Forflight just added the feature. 

[tony]

So the glide ratio is 12:1?  At what speed?

 

[Hank]

4 hours ago, tony said:

So the glide ratio is 12:1?  At what speed?

 

In my C, it's 105 mph. Should be in your Owners Manual like this (at the bottom of fhe page):

[tony]

Hank, I found it.  105 for me too.  Thanks!!

[Bob_Belville]

Of course Vg varies with weight and should be close to Vy.

In my E 105 mias (91 kias) at 2575#; 97 mias (84 kias) at 2200#.

I round all that off for simplicity: In an emergency, I would quickly trim to ~90 kias and concentrate attention to other matters - engine problem? choose landing site? declare emergency and get help? Find fire extinguisher?  

[Browncbr1]

My 67 F poh says 2.2 miles per thousand at gross (2740lbs), 100mph, Clean, prop pulled. 

[MB65E]

I like that 2x factor number in a short body. It matches the C model chart well. So in a short body. Say altitude you have to loose i.e. 8500ft. (8.5)  x 2 = 17sm worth of glide. But....

That's one reason to keep everything in MPH or at least  convert the chart because your GPS says you have a good airport at 15.7NM!!! But your only going to glide 14.7nm on a good day. Darn! Lol. 

-Matt

 

[tony]

or just put put the parameters in foreflight and see it represented graphically on the map

[Stephen]

22 hours ago, tony said:

or just put put the parameters in foreflight and see it represented graphically on the map

Yes, it is a circle on flat land and a partially eaten cookie if there is any terrain

[Hank]

On 10/4/2017 at 4:05 PM, MB65E said:

I like that 2x factor number in a short body. It matches the C model chart well. So in a short body. Say altitude you have to loose i.e. 8500ft. (8.5)  x 2 = 17sm worth of glide. But....

That's one reason to keep everything in MPH or at least  convert the chart because your GPS says you have a good airport at 15.7NM!!! But your only going to glide 14.7nm on a good day. Darn! Lol. 

-Matt

 

The Book for my C says 2.3 miles per thousand feet, which is coincidentally 2.0 nm per thousand feet . . .

Just saying.

Sometimes what we engineers call "significant digits" are actually significant. Either someone rounded to get 2 miles per thousand, or somewhere along the line the "nautical" was lost. 1nm = 1.15 sm

[Ned Gravel]

This is why crossing Lake Michigan is possible at 12,000’ without life jackets at the 45 nm crossing between Sheboygan and Little Sable Point.  At no point would we be beyond gliding to shore.  

[Hank]

8 hours ago, Ned Gravel said:

This is why crossing Lake Michigan is possible at 12,000’ without life jackets at the 45 nm crossing between Sheboygan and Little Sable Point.  At no point would we be beyond gliding to shore.  

But the chute, Ned! The chute will save you . . . Like it did the 182 when his door popped open on departure. Wonder if BRS will count that as a save, too?

[Ned Gravel]

1 hour ago, Hank said:

But the chute, Ned! The chute will save you . . . Like it did the 182 when his door popped open on departure. Wonder if BRS will count that as a save, too?

Ya, right............

[MyNameIsNobody]

Garmin Pilot has pilot settable glide ratio rings.

[MyNameIsNobody]

I set mine in Garmin for 10.3 the pessimistic prop windmilling.  Still almost 15 miles at 7500 feet.  100MPH best glide if prop stopped and 105MPH if windmilling in my M20E

[gsxrpilot]

4 hours ago, MyNameIsNobody said:

Garmin Pilot has pilot settable glide ratio rings.

Same in ForeFlight

[Hank]

7 hours ago, MyNameIsNobody said:

I set mine in Garmin for 10.3 the pessimistic prop windmilling.  Still almost 15 miles at 7500 feet.  100MPH best glide if prop stopped and 105MPH if windmilling in my M20E

Same numbers for my C. No idea if they changed when the Hartzell 3-blade was put on.