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These pusher designs were marketed featuring high cruise efficiency.

No doubt the pusher configurations offered advantages in propulsion efficiency and cabin comfort, but how did this compare to aerodynamic efficiency?

What was the Vbg and glide ratios of the Rutan VariEze and Beechcraft Starship aircraft as compared with, for example, a Beechcraft Model 18 or a Piper Cheyenne?

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Below is the glide distance diagram out of the Varieze POH. enter image description here

As I read this, it looks to be about 10:1 with engine out and a windmilling prop.

The Long EZ is a tad better:

enter image description here

It looks to be about 14:1 with engine out and windmilling prop. In idle it is about 17:1. That works out to be about a 3.2 degree glide slope, only slightly steeper than the standard 3 degrees.

I fly a Long EZ, and I can tell you from experience, one of the hardest things (not that anything is hard, it's a joy to fly), is to control airspeed in the traffic pattern, the airframe just wants to go fast. In idle power, on a normal glide slope, unless you have a stiff headwind, you almost always have to either slip it a bit, deploy the landing brake or fly a lower, shallower final to keep the speed down.

For all canards, this is because, unlike conventional tailed aircraft, where the horizontal stabilizer must be generating a downwards aerodynamic force in order to create the pitch up moment necessary to compensate for the pitch down moment of the lift on the wing, the canard, being at the front of the airframe, is also generating an upwards aerodynamic force to do that. So the total aerodynamic force, (and corresponding trim drag) is less.

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  • $\begingroup$ Good data to start. Improvements with the gear up Long, and where these really shine is in cruise. Yes, I think I would use that speed brake and come in a little steeper. Need info on the Starship, these first 2 are holding their own. $\endgroup$ Commented Dec 2, 2022 at 19:57
  • $\begingroup$ @Robert, Exactly! In case of engine failure on final! Nice to be able to just raise the speed brake and have extra glide distance available. Also, for need to go-around. In T-37's in UPT, we used speed brakes on final so we could carry higher rpm for go-arounds because of long spool-up time required on centrifugal flow turbojets. And sorry, don't know about Starship... $\endgroup$ Commented Dec 2, 2022 at 22:00
  • $\begingroup$ I fly gliders, but not a LongEZ. However, I believe the reason why the LongEZ is efficient is the same as the glider, and has nothing to do with the canard vs empennage. It is due to the very narrow fuselage profile, attained by having the pilots be practically prone. There's a great site on this, created by someone who was developing a canard homebuilt: apollocanard.com/4_canard%20myths.htm $\endgroup$ Commented Dec 3, 2022 at 14:09
  • $\begingroup$ Well, I guess any and all performance metrics are affected by all airframe characteristics, no single characteristic can be held to be accountable. But given the same other general characteristics, the greater the drag, the worse the glide ratio will be. And an airframe with a canard has lower trim drag than the same airframe would have with a conventional tail. $\endgroup$ Commented Dec 3, 2022 at 14:52
  • $\begingroup$ And, in reading the referenced article, it has some clear obvious mistakes. It mentions, several times, that canards limit AOA, and therefore cannot reach their maximum lift coefficient. This is irelevant. Minimum drag (L/Dmax), occurs at significantly lower AOA than at the maximum or stall AOA. $\endgroup$ Commented Dec 3, 2022 at 14:57

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