ducted fan gyro

[Sapientino]

In your opinon does a ducted fan gyro require an orizontal stabilyzer or not?
I think it does not require since the duct should work as a stabilyzer but I'd like to hear your opinions, especially concerning engine switch off situation

[birdy]

If it dosn't need a horisontal stab, it won't need a virtical one either [ fin], theoreticaly.

[enewbold]

In your opinon does a ducted fan gyro require an orizontal stabilyzer or not? I think it does not require since the duct should work as a stabilyzer but I'd like to hear your opinions, especially concerning engine switch off situation Well, I'm also not certain at all about it, but I would hazard a guess that it WOULD require additional stability, over and beyond what a ducted fan shroud can offer, especially considering that the shroud is located around the airflow the engine is producing. The stabilizers (HS and VS) would be situated IN the airflow.

But remember... this is a guess on my part!

Ed in Columbus

[SamL]

http://www.sciencetech.technomuses.ca/nam/Digital_archives/english/search.cfm?&records_to_display=34&model=Avian%202/180%20Gyroplane&designer=Avian&searchtype=designers

Sorry mate, but it has already been tried.

Try the above link, or search under Avian Gyroplane.
Regards Sam.

[enewbold]

http://www.sciencetech.technomuses.ca/nam/Digital_archives/english/search.cfm?&records_to_display=34&model=Avian%202/180%20Gyroplane&designer=Avian&searchtype=designers
Sorry mate, but it has already been tried. Wow. Thanks for the link. If you look inside the shroud, you'll see the vertical stabilizer built right into it.

I wonder what ever happened to this design. It looks really interesting! Kinda like a Barnett.

Ed in Columbus

[enewbold]

I wonder what ever happened to this design. It looks really interesting!The Avian gyrocopter was a pusher design with a ducted Hartzell propeller. The rotor was an articulated 3 bladed semi-rigid, high inertia design. For this reason, a substantial drive system was required for rotor spin-up. On the original prototypes there was a 3 inch wide, heavy duty,square toothed belt that transmitted engine power from a smaller driver sprocket to a large driven sprocket at the base of the rotor hub. Occasionally, during a spin-up, this belt was stretched by some horrendous load so that the belt teeth would no longer engage the teeth on the driven sprocket causing the belt to ride up on top of the sprocket teeth. The resulting high load on the sprockets caused the structure that supported the bearings to collapse (A round toothed HTD type belt would have eliminated the riding up problem of the square tooth belt but it had not as yet been developed in the early 60's.)

About this time, Avian started to develop and build their last prototype. It was totally redesigned and much improved in every way over the previous prototypes. One area of improvement was the rotor spin-up system The upper belt width was increased to 4 inches and the structure that supported the sprocket bearings was made more substantial. A new hydraulic multi-plate clutch was designed with more torque capacity and mounted over the engine near the propeller end. This improved drive gave the new prototype absolutely phenomenal jump take-off performance. The gyroplane was capable of jump take-off to 50 ft. The problem of the upper bed drive had been solved by the brute strength approach, using a stiffer support structure along with a wider belt and sprockets. Nevertheless, as time went on other problems started to show up. The lower belt drive, that took power off the engine seemed to flop a lot at various times. After a few spin ups the clutch would become very hot and eventually turn blue in color. If the cowling was removed, immediately after a spin-up the clutch would appear to have been red hot. The torsional loads going through the drive system appeared to be much higher than the original analytical numbers indicated. I had heard about torsional vibration during my college years but at the time it never hit me that the problem with the drive system involved torsional vibration. As far as I know, the clutch problem was never solved.

[Sapientino]

[url]Sorry mate, but it has already been tried.

Try the above link, or search under Avian Gyroplane.
Regards Sam.

I knew Avian (infact I was thinking about it) but I wonder if it stable or not?
remember that in thouse years also for common gyro the orizontal stabilyzer was an optional!!!

[enewbold]

Whatever happened to this design?

It turned into:

Pegasus Rotorcraft Ltd.
http://www.pegasusrotorcraft.com/photos.html
reinhard@pegasusrotorcraft.com

This is just a small sampling of the Pegasus MkIII photos. As one can readily see, the design is aerodynamic with clean, modern lines. Note the contour of the fuselage which allows for unobstructed visibility below. The large windows are also contoured and great care was taken to make sure that all are optically correct (no distortions). Notice the uniqueness of the ducted propeller. This design results in four things:

1) 1320 Pounds of static thrust
2) More rudder authority
3) Less noise
4) Increased safety

[Brent_Brown]

I think all of the troubles with this gyro can be fixed. No real need to jump 50 feet each time anyway. This thing had loads of thrust and flew great as seen in the videos off the web site. I emailed the guy who has all rights to this gyro. He would like to get it in production but we all know that is $$$$$$$. He said he still has one of the last ones tested.

[jdalexa]

Hmmm.. how would this thing handle if yawed considerably? the A&S 18A can't take much yaw at all.

Seems like with the engine running, this thing would do well, but how about with the "pilot cooling device" (prop) stopped???? That's a lot of area along the side.

Hmm... they call it Certified and show a Type Certificate... I thought there were only two... Attached is the Type Certificate Data Sheet from the FAA site.

[Sapientino]

Hmmm.. how would this thing handle if yawed considerably? the A&S 18A can't take much yaw at all.

Seems like with the engine running, this thing would do well, but how about with the "pilot cooling device" (prop) stopped???? That's a lot of area along the side.


That's my biggest concern about this design even if it is very interesting,
Maybe could be interesting to build a model to investigate