SIG Kobra going Ducted fan, possible?

[Coyote24]

Good day,

So there is this SIG Kobra kit box sitting around (kit # RC53) and I was now wondering if I could put a ducted fan in it instead of prop on the nose.

The initial idea is to make openings on each side of the fuse somewhere under the cockpit to feed air to a fan inside the fuselage with a tube leading to an open tail.

I have no idea if this is feasible, but the reason the kit was never built is because of the idea of having a prop on the nose (or tail) of a jet is not appealing.

If you are not familiar with the kit it is a F-16 type of plane.
45" ws
390 sq inch wing area
weight 3.25 to 3.50 lbs
usual engine recommended is .19 to .35

http://www.sigmfg.com/cgi-bin/dpsmar...FV5.html?E+Sig

Any idea suggested would be greatly appreciated.

Cheers,

al

[tampaflyer]

anything can be done...

it is not going to be easy. a d/f needs alot of air intake . at least 100% fan sweep area. you will have to make inlets, a tail tube. reroute any pushrods, or anthing els in the way. plus you will have to make sure you don't make it any hevier.

and to be honest, even with a High KV motor.. it would be a great propdrive. once spinning you wouldn't see it, what ruined it nitro was a muffler hanging down.

[JetPlaneFlyer]

While not 'impossible' this would be very difficult. Looking at photos of the Kobra it's basically a standard i.c powered aerobatic model with some superficial jet stying. the fuselage would not be wide enough to take a EDF outlet and the nose would be too short to get the plane to balance without an engine up front or a load of lead. You would also need ducting on the inlet to the fan and as noted by Tampa the area of the duct needs to be about the same as the fan area.
Basically you would have to design a new fuselage if you wanted to go EDF. EDF's are much less efficient than normal props requiring much more weight and power to make the same thrust as a normal prop. You would end up with a model that was a lot heavier than the prop version so handling and manouverability would be worse.
I honestly cant see a reason to do the conversion. This is not a jet model, it's a normal aerobatic prop model with a little jet styling, once it's in the air you wont see the prop anyway.

[Coyote24]

Thank you both.

I was afraid this would be the situation!
It is still a nice plane.

Cheers,

a