Glide Ratio

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Years ago, after a partial engine failure in my G-200, I decided to conduct some tests to determine best-glide speed and glide ratio. I didn't end up capturing as many data points as originally planned, but the numbers were still pretty interesting.

--> If anyone has additional data points, please send them to me and I'll happily include them here.

Key take-aways:

  • The G-200's glide ratio is somewhere between Pitts and Cessna
  • The best-glide speed is fast!
  • The descent rate is also fast!
  • The prop setting makes a tremendous difference, especially at higher airspeed

Test conditions:

  • Timing and distance are for a 2000' ft descent, starting at 9000' MSL and ending at 7000' (a downside of living in Colorado -- the dirt is more than 5000' above sea level)
  • Calm winds aloft
  • Gross weight: approx. 1220 lbs.
  • Angle-valve IO-360 engine with 10:1 pistons
  • 200cm MT prop

The results:

Airspeed (KIAS) Distance (nm) Ratio Time (sec.) Descent
Rate (FPM)
Prop
110 1.8 5.94:1 65 1846 Fine
110 2.3 7.59:1 73 1643 Coarse
120 1.5 4.95:1 47 2553 Fine
120 2.6 8.58:1 75 1600 Coarse

 

Glide Ratio

Interesting, i was getting something like 1000fpm inidcated descent rate @90kts  which is around 9:1... At something like 5000' altitude

I think you can double that

I think you can double that glide ratio with the prop stopped.  I did some stall testing with my prop stopped and was impressed with how shallow the nose down attitude was in a normal glide.