Is a GB type appropriate for us

[Flatliner]

Hi all,

I have a newbie question. My father and I are in the early stages of exploration. We are considering building a pair of Gyrobees but will get them N-numbered as experimentals and get our sport pilot liscenses. We are both BIG guys (I am 6'5" 250 and my dad is 6'1' 300.) My question is if a Gyrobee with a 503 would work for us given our size. If so, what would be any considerations you would throw out there for us.

Thanks
Robert

[WingNut]

I wondered about that. There is a Gyrobee for sale locally with a 582 Bluehead, looks like he has done some extra mods to it tho. Can anyone give a short explaination why it is bad. I was actually considering buying it in the future if it is still for sale when I have the cash, and checks out to be a good buy. Sry for semi-hijacking your post, but I figured it was semi-relevant...

[GrantR]

I dont know what Rick Martin and Jon Carlton weight but they are/ were flying gyrobees with a 447 and 503 with success.

At Bensen days they looked like they performed well.

[Flatliner]

No problem, I will ask another question as well. What other designs are available that we could plans build, we are both capable machinists and are as interested in the building aspect as the flying.

[jcarleto]

I fly the GyRonimo, a gyrobee hybrid at an all-up weight of 250 pounds along with 5 gallons of fuel with a 503 Rotax. It performs very well. Last year, I was at 270 and had some issues in 101 degree (F) temperatures off grass, but otherwise it was OK. I have flown it in winter with a pilot all-up weight of around 300 pounds....the difference being warm clothing and boots.

The key is going to be stripping it down. I have no pre-rotator...no instruments (though I do use a Hall aistpeed tube), and no electrical system. I have considered converting it to an Experimental, and adding a pre-rotator, electrical system and a few creature comforts, but for my weight, I am sure I'd have to up the engine horsepower.

Here are a couple of video links of the GyRonimo carrying me at around a 250 pound all-up weight in fairly warm weather:

http://www.youtube.com/watch?v=LuHDlzTC5WY
http://www.youtube.com/watch?v=hvaqFRoVnVY

A better choice for your weight might be a Dominator UltraWhite (it isn't ultralight). It is available kit or plans.

*JC*

[Flatliner]

Follow-on question. Is the reason the 582 is bad because of the increased power in the case of a lighter pilot. In other words, could we get away with a 582 or comparable engine knowing that we, as big guys, would be the ones flying it. If I understand the stuff on PIO from the gyrobee site, it is already very close to a CLT machine without the gangly (sorry, just my personal opinion) appearance of some of the other designs. If that has something to do with stability, could we use a 582 and increase the stab area?

[GrantR]

I tried to find the thread about using a bigger engine on the GB I could not find it.

If I remember right when you put a 582 on the machine you are adding weight below the engine due to adding the radiator and probably beefed up engine mounting.

I think the other thing was using a bigger prop. I am pretty sure the 582 needs a taller prop than the 447 or 503. That moves the engine up the airframe thus raising the thrustline. The original bee was designed with low power and low rotor disc loading which made it docile yet perform well with the low hp. This makes it’s a forgiving trainer for new pilots.

So sticking a 582 on it results in a higher powered bee with a high thrustline.

[Flatliner]

Thanks for the great response, I hadn't even considered needing a longer prop. Let me ask another potentially stupid question. If the design will handle a 250lb load as outlined in the plans, would a slight increase in rotor disk size increase the useful load or does it not work that way.

[MikeBoyette]

No problem, I will ask another question as well. What other designs are available that we could plans build, we are both capable machinists and are as interested in the building aspect as the flying.
Yes sir you could look into a Dominator. www.rotorflightdynamicsinc.com plans are $175.00 and there is an assembly manual too. I am not sure of cost of manual.

[jcarleto]

There is another issue with putting a 582 or similar engine on a Gyrobee. The torque is going to be quite a handful on take-off. For that matter, it will probably be an issue anytime there is a significant power change. Additionally, the stock bee motor mounts won't be heavy enough.

Being large-frame is a problem with most gyros. For that matter, it's a problem form most light aviation equipment. You almost have to abandon the lightweight stuff and go right for the step-up model. Just an aside...most lightweight two-place machines make a really nice machine for a large-frame pilot. Take out the second seat and add more fuel capacity!

*JC*

[RICK MARTIN]

The original gyrobee had 25' Rotordynes.

The Monarch in our hangar uses a 582, B box and a 60" Powerfin. It flies great. I just wanted to point out that a 582 doesn't have to swing a larger prop.

[GyroRon]

You could put together and fly a gyrobee with a Rotax 582. Also a alternative engine that seems to have a few satisifed owners is the MZ202 which should give you more power than a 503 but a little less than the 582, with much lighter weight and a more simple installation.

There has been Rotax 618's installed on Gyrobees successfully, so I have no doubt a 582 would work on one.

[Dean_Dolph]

Ron, has a ton of experience so I wouldn't dare take exception to what he says. However, I think there is a thread here somewhere that talked about Jay Boyce's 582 powered 'Bee and that it could be handful. But, I'm not sure what that means other than apparently it would get your attention when taking off or on adding throttle.

[giro5]

I am wondering if one buys an already assesembled unregistered plane can you register it experimental. I thought the builder had to register it. One can certainly buy an already registered experimental. Am I out in left field on this??

[Chuck Roberg]

I am wondering if one buys an already assesembled unregistered plane can you register it experimental. I thought the builder had to register it. One can certainly buy an already registered experimental. Am I out in left field on this??

The general answer is Yes. If you can show it was built either by showing the original builders building log. Of if it's on the FAA's 51% list. Or you have an understanding DAR.

If you are able to get it registered Experimental. (You should be able to) You will not be able to apply for the Repairman's Certificate. The conditional Inspection will have to be done by the original builder (If he applied and got the Repairman's cert.) Or at a Minimum an A&P.

[kiwirebel]

[QUOTE=GyroRon;305688] Also a alternative engine that seems to have a few satisifed owners is the MZ202 which should give you more power than a 503 but a little less than the 582, with much lighter weight and a more simple installation.QUOTE]

There was up until recently a gyrobee (Starbee I think...) flying here in New Zealand that used the MZ202, and the pilot absolutely loved it! It was great to see it fly, and seemed to have quite a bit of power available. Another consideration too is that the MZ engine is only around 2/3rds the price of a rotax.

There are a few issues that have come to light recently with the MZ, but they relate to the installation in the mosquito helicopter, and running the engine at flight rpm (6100rpm) with no load on before the pilot pulls pitch. In an application with a prop that always provides load to the engine, it does not have the problem.