Rick asked:
> What is the Glide Ratio of the 415-CD and best Glide Speed?

We don't have an accurate set of numbers for this.

I did very careful glide testing and would have been able to give an
accurate answer except that my airspeed indicator was WAY off accurate
back then - and I don't know by just how much.

In the process, I did learn something about gliding in the Ercoupe.  I
had an extra interest in this subject after my one forced landing.
http://ercoupe.org/Fly-in%20Reports/Gas-line-ice.htm 

Testing confirmed what we all know - at low airspeeds the short, thick
wings on the Coupes produce a high sink rate.

The surprise was that at higher airspeeds, the gliding sink rate wasn't
bad at all.

Making a correction for the faulty airspeed indicator, I found that the
best glide ratio occurred in the 75-85 range with the higher speed tail
of the curve being only mildly sloped.  I'm guessing the true glide
ratio at about 78-80 mph was about 10:1.  At 10 mph faster, the glide
ratio was only a little bit less.  At 10 mph slower, the glide ratio was
a LOT less.

What you need to do FIRST is to calibrate your airspeed indicator to be
sure it's correct.  We've found that a LOT of ASIs can be in
considerable error, usually on the high side.  I was very happy with the
115-118 mph my Coupe flew but eventually got suspicious when it I always
took lots longer to go both directions in an out and back flight
compared to my flight plan.  It turned out my Coupe, with its climb
prop, was really flying 100 mph at that rpm.

Here's more about ASI errors and calibration:
http://edburkhead.com/Ercoupe/airspeed_indicator_errors.htm 

Ed

Ed Burkhead
http://edburkhead.com/Ercoupe/index.htm  
ed -at- edbur???khead.XXX        change -at- to @, remove ??? and change
XXX to com


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