Hi Folks,
I have a Bridi Big Bee 96" span shoulder wing plane that I want to be able to hang on the prop at my field at 6100' MSL. Will a Zenoah G-62 be enough with a 22-10 prop? Or do I need an 80cc single? I have torque rolled many 40-60 size planes with a Saito 91 (at sea level) but this will be a gasser, and at my altitude I expect a 15% power loss. I'm thinking the 80cc single will be needed. Wing area is 1600sq in, weight is 11lbs plus motor= 16lbs. -Tom in Colorado Springs, CO

50cc on up 80cc would be too much imo

a DLE55 will be fine with a 22x10

G-62 would be OK if it is converted to EI.

DL-50, DA-50 would both work fine

All depends if you keep the AUW to 16 or less. If you get to the 19-21lb range you are going to need a bigger motor.

Thanks for all the replies! I noticed that ChiefAircraft.com lists the DL-55 as having 12.5kg of thrust at 1800 meters which is just about 27.5lbs of thrust at 5904ft. If AUW is kept to 16lbs which I'm sure it would be with the DL-55's light 2.9lbs of engine weight, that would give a 1.71:1 power/weight ratio. Is this enough to blast out of a TR? At sea level it would have 14.2kg or 31.24lbs of thrust, a 1.95:1 power/weight ratio. At 19lbs AUW that would be 1.64:1, probably the bleeding edge of acceptable. The motto around here is "Motor-up and Wing-up" meaning use more motor and increase wing area. I think the Big Bee is already winged-up, I'm just concerned about enough motor. Maybe a 70cc motor if there is one made? -Tom

The DLE-55 is gonna be more than enough on 16lbs at your altitude. I live at 3250ft and 2 guys at our club are pulling 29.5lbs and 30.5lbs of thrust with their new DLE 55's with 23x8 XOAR props on stock exhaust. Props are really what will determine your models thrust and flyability.

Maybe I'll be under 16lbs. Anyone know what a DLE-55 weighs with muffler, ignition, battery, prop, spinner, and mount? Where do you get Xoar props and what's the best place to get DLE-55 engines? I'll probably have to add some surface area to the elevators and rudder, here's the link to the Big Bee ad [link=http://www.bridiairplanes.com/hangar/bigbee.html]Big Bee[/link]. Mine was already built, I will get an as-built weight on it in the next few days. I bought it at an auction for $80, it's covered in fabric and built nice. The auction prices on airframes were low, I got a 72" PT-19 for $70 too, although that's just going to be a scale bird. -Tom

I am just concerned how a 96" wingspan plane is only weighing 11lbs. Sounds like it is built sparingly and will break apart. I just checked the website that has them for sale. $180 new? Dude, you get what you pay for.

11lbs plus engine=16lb? Nope...

11lb airframe, 5lb engine, exhaust. ignition, ignition and receiver batteries, fuel tank, servos, receiver, control horns, pushrods... Then weight loaded with fuel. add tailweight to counder the motor up front.

It adds up really fast.

Get a diffrent airframe. is my .02

We'll see what mine weighs, the Bridi designs have been around for probably 20 or 30 yrs and are pretty well documented. I think it's because the fuselage is so small, it's basically a narrow box, not a scale design. The 96" wing is ONE piece, it's like carrying a surfboard! It barely fits in the roof of my Tahoe. If it holds up as well as the Bridi Kaos, it will be ok. I've done 100mph snap rolls with the Kaos design. I think the DLE-55 is 2.9lbs, looks like a minimal crankcase like the DA-50, with standoffs to mount it to the firewall. I think the wing design is the same as the Kaos, and the fuselage looks like an upside-down Kaos. I believe the $180 price is for an all-balsa kit, it probably takes another $150 in supplies to finish one. Mine has a big tall landing gear, and had a Supertigre 2500 mounted on it. There's no way I'm feeding a 25cc glow engine, I'd much rather feed a 55cc gasser!

Dude, you don't know what you are talking about. Bridi kits are very well built, overbuilt in many cases. This is a good plane and sounds like a very nice deal.

Wingspan99, I used to fly with a guy who built one of these as a "giant scale trainer" for his kids. It was a very sweet flying plane. As i recall it uses the same fat airfoil as the Kaos. It had the same sweet stall characteristics as the Kaos.

I used to have a 90" J-3 Cub. At the time I had a Bronco and the wing just BARELY fit, it was like moving a surfboard as you said. It had a Webra 1.20 and would torque roll. It weighed around 12.5#, and closer to 15# on floats. The DLE-55 would have been a significant increase in thrust.

Back to the Big Bee, the plane was originally designed for up to a 3.7 cu in engine, which is about 60cc (60.63218...). Since you already have a G62 you could use that and it will work great. If you want to buy an engine go for a modern 50cc engine. I think an 80cc engine is definitely overkill in this situation. You could move the firewall back as needed to avoid using tail weight.

This will be a very fun plane!

I'm going to order a DLE-55 from Tower Hobbies. They're $409 but with promo code 014G7 $60 off it's $359. That code is for SS members only, that's $10 more for the membership but that gets you free shipping then. The best price I saw on it was $319 at HobbyKing.com but they must be outside the US or something, they don't have UPS or Fedex as shipping options, and their shipping charge was $35 on it. Sheesh. I wish I had the $100 off $400 order promo code. I tell you what, the TroyBuiltModels.com site offers it for $409 with a free ignition battery eliminator/share/filter device for on/off of ignition with $15 off for a shipped price of $411. I like the device itself!
The Bridi stuff is very well designed and the Big Bee indeed has a fat symmetrical airfoil. The ailerons are probably ok but I'll add some surface area to the tail surfaces, maybe aerodynamically balance them a little. It was covered in fabric and painted yellow with black stripes and it says Seabees on the side, a tribute to someone's Seabee service no doubt. I think it's just really cool. I want to mount the engine upright so the head sticks up like the glow motors used to in the old days. I wonder if it would be a problem for the DLE-55 to be mounted upright, I doubt it. The muffler will still be pointed down, I just want to see those big old cooling fins and spark plug sticking up. The cylinder pointed upwards will help the shoulder wing bird hang straighter on the prop too.

Ok after flying this plane for several months (maybe 40 flights) I have come to the conclusion that is is just too ugly!! The DLE-55 pulls it great with a 22x10, not what I'd call 3D, it will hang on the prop but falls out when it starts to TR. My density altitude is typically 8K MSL so that has a lot to do with it. It is 16lbs AUW. It lands very realistically, like an overweight airplane at high altitude. I use flaperons coupled to the elevator for high lift in the flare and it works great. Anyway I'm going to tear the engine and radio out of it, that engine is just too good for it! And the digital servos on the elevators are like shoe polish on a turd. Maybe if I flipped the fuselage over, put the wing on the bottom, a canopy on top? I'll call it the Kaos.

Tom, didja buy that at the Jefco auction? lol, some good (and bad) deals to be had there...I was there on Saturday last year. You could always take it back to the auction this year...

I have a DLE55 on a 16lb 2oz Reactor, and it hovers it just fine. Lots of nice 50cc planes out there today to plug that 55 into...

Yes, I got that at Jefco, for $80 I couldn't pass it up, with that 96" wing. It will back at Jefco this year if you want it! I'm planning on a 6' diameter disc like a Rountuit for the DLE-55. 2" thick foam is soooo easy to work with. The more I look at it, the more I realize I could move the wing to the bottom by cutting a wing opening in the bottom, and avoid having to do anything else to it except close up the top and reposition the servo tray. It would look waaay better and probably fly truer for pattern. Then I need a canister muffler for the DLE-55 because the box muffler that came with it is LOUD. Know any good canister setups? Can I make one up, like a mousse can muffler?

lol, I'm looking for an RC Guys Decathlon. There was very nice one there last year, but I'd already bought a plane and a couple power tools so I had to pass. Didn't know what a Rountuit was, so I googled it. A 6' one with a 55cc would be interesting!

Never messed with canisters, but a commercially available one or a mousse can style would be good. Not many guys around here run them, as most aren't worried about noise in the Rockies, but I did hear a Pitts Python/DA85/canister setup a year ago and it sounded sweet! Much nicer tone than the stock mufflers.

I'd like to make a 6' Rountuit with the DLE-55 and then make a 16' Rountuit with a Rotax 503 or maybe a turbine engine.
I simply cannot believe how electric motors and Lipos have come down in price. I can buy an electric brushless motor that will spin the same prop as the DLE-55, for about $55! 5000mah 6s lipo's are down to $65. It's just off the chart. I'm seeing price drops on Hobbyking.com that just bug my eyes out. Eventually all RC will be much cheaper to do electric than gassers even.