[wingnut]

Hey gang:
I'm building a 2m. me262 from plans i got from mwavesdave.I built it with electric ducted fans,the batteries and fan units pushed the final weight up to14lbs.4oz. which I thought was not too bad but when I did the calculations for wing loading it comes out to around 44 oz /ft sq. I think this is very high.I am waiting for 2 ESC s I ordered a while ago so I have not flown it yet.Are those skinny wings going to be trouble.Any thoughts? Regards

[Mike Sebastien]

Don't fly it slow

[wingnut]

You gotta land sometime Mike.

[Mike Sebastien]

Originally Posted by wingnut

You gotta land sometime Mike.

And that where the problems could start. I am sure there is info out there that could give some guidance.

[mwavesdave]

I'd say the four flaps will be a requirement, the 262 is a jet after all, so high wing loading and higher landing speeds will come with the turf. Mine, with twin nitro .45s might hit around 10 pounds, but I built her very light, and I'm not hauling the weight of EDF unit and batteries. I'll do some digging though, off the top of my head, 44 oz wing loading might not be too bad for it.

[mwavesdave]

First bit of research:

The BVM Mig has a wing loading of 50 oz/sq ft. Most of their other scale jets are similar. Stall speed increases with the square root of wing loading so it goes up slowly with weight. Stall speed is therefor not the big problem - it is drag or having enough of it to land easily.

[mwavesdave]

Typical jet wingloadings are in the 50-60 oz. / sq. ft. range. IMHO, I think you should look for a trainer in the 40-50 oz. / sq. ft. range to get a real introduction to the jet experience. In jets, its all about the landing, and the higher wingloading is one of the factors that makes that a challenge. Anything in the 25 oz. / sq. ft. range is really too much like a sport model to really prepare you to fly jets.

[mwavesdave]

Another one, from JetCat USA:

Wing loadings are different on the type of jets out there on the average. Aerobatic/sport jets have the lower wing loadings where as the scale birds get a little crazy. I personally fly the BVM line and can only comment on those. A KingKat is about the lightest loaded jets there currently is available in the conventional design. I has a cool 1600 square inches of area and come in around 37 - 38 ounces per square foot for the wing loading. This plane is very light on the sticks (for a jet mind you) and is very aerobatic. The BVM Mig 15 is one of the nicest flying birds out there and the wing loading on mine tips out at 73 ounces per square foot at takeoff. It weighs in at 28.25 pounds ready for takeoff wet and has a 900 square inch wing. I personally love the way it flies. It is heavy on the sticks, but not extremely heavy, and does not get pushed around by the wind. I have flown BVM F-100's that have hit the wing loading scales at over 80 ounces and I love them as well. You need to carry power on final with these birds and they definitely are not for the begining jet pilot. But once you have some time, most guys fall in love with them as they are very positive and honest in how they fly.

Flying a few heavy WWII type models will help you get ready for the jet world. Most people get into the speed thing, but that is only a small portion of it. Wing-loading as you have thought about is the key. This will kill you in a heart beat if you get behind the power curve. Learning how the flaps will work for you in how they affect the way a heavily loading bird flies and changes with the application of flaps is another part of the equation. All in all the large aerobatic birds don't really prepare you for the jet world at all. They fly like big kites compared to a jet, and the landing speeds are another area where they are lacking.

Try to keep the wing loadings down under 55 ounces for the aerobatic arena and under 45 ounces for your first one. These should give you a higher possibility of success. The new Composite Bobcat would be the perfect jet when coupled with a JetCat P-60. Weights are down, flying times are up and the wingloading is about a sweet as it can be.

[mwavesdave]

Forgot to mention as well, while you can't accurately take into account the "lifting body" area of the 262, there definitely will be. The flat wide bottom, with curving narrow top, will indeed provide lift, that was part of the design shape of the real deal. A wild ass guess, would be about an additional 2 square feet of wing area, taking into account the fuse. I also have the exact same airframe, built with two OS .46 nitro DF units, tuned pipes, and very heavy air retracts, a friend of mine gave to me. It was used for many years, and flew in many scale competitions, you could compare thrust output of the two nitro units to thrust of your EDFs, think you've probably got more thrust, and less weight. I'd keep the speed up on the first few flights, as well as testing out the stall, with and without flaps, at altitude that you can easily recover from.

[Trumpetman]

What he said!