Glide ratio help

James331

James331

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James331
so maybe I'm just not doing my math right, but what would the glide ratio on this be?

IMG_1406.jpg


Thanks!
 
About 7.6:1, by my math.
 
10nm at 8,000
60,760 to 8,000
=7.6
 
Sweet

Thanks guys!
 
Simple way to read it, 6000 feet is about 1 mile up. Looks like about 7.6 to 7.8 to miles for 1 mile up.

Brian
 
That is with the standard Cessna 3 blade. If you have one of those monster P-Ponk props, the glide will be less.
 
Doesn't that work out to a 7.5 degree glide slope? If so that'll be easy to remember. 7.6 ratio, 7.5 deg. slope.
 
How much of a difference is there in stopped prop vs. windmilling? The manual above assumes the prop is windmilling. It would be interesting to see what the difference is.
 
A stopped prop has considerably less drag than a windmilling prop.
 
A windmilling prop, depending on number of blades, etc., can have the equivalent drag as a solid disc of the same diameter, or a bit larger. Probably not/not nearly that bad on a two bladed prop, maybe as bad or worse on a four bladed prop?
 
If you have your glider ticket then the whole calculation is off. Log it as glider time and you're allowed to catch thermals. Declare an engine out emergency with ATC and you'll never make the end of the runway.
 
Lachlan said:
If you have your glider ticket then the whole calculation is off. Log it as glider time and you're allowed to catch thermals. Declare an engine out emergency with ATC and you'll never make the end of the runway.
Click to expand...

I was taking my commercial airplane checkride and the examiner pulled the engine failure trick. I passed through a thermal and turned within it, zeroed out the sink rate. I looked at the examiner and commented in jest, "if this keeps up we just may make that runway over there." He grumbled something about %#&@ glider pilots.
 
Dana said:
A stopped prop has considerably less drag than a windmilling prop.
Click to expand...
A stopped prop shows the correct time twice a day.

Lachlan said:
If you have your glider ticket then the whole calculation is off. Log it as glider time and you're allowed to catch thermals.
Click to expand...
Climbing in a thermal with a 185 on floats would be an impressive trick!
 
Serious question. Is this for the new ForeFlight function which, understandably uses feet:feet for calculations.

I ask because I think of glide ratio the same way as the chart: in feet:nm format. "That airport is 5 miles away, I think I'll make it" is difficult enough. "That airport is 30,380 feet away" doesn't compute mentally for me at all.
 
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