<span class="Apple-style-span" style="font-family: Verdana, Arial; font-size: 13px; -webkit-border-horizontal-spacing: 1px; -webkit-border-vertical-spacing: 1px; ">Will this plane fly? This is just the initial sizing.

Chord = 5.5"
Wingspan = 42"
Rectangular wings.

fuselage = 8.5" x 4.5" x 3.5"
estimated empty weight = 1.5 lbs

Here's a rough sketch....

Question: Will this be able to carry a payload of around 2.5 lbs based on the wing design? AR ~ 7.2
I'm afraid the chord is too short but thats the max i can do.

Any Iputs?

Thanks.</span>

It could fly, but with a wing loading of 40 oz/ft^2 it will need high take off and landing speeds.

An outhouse will fly if you give it enough power. It won't fly well mind you but it will fly. Your talking a wing load of nearly 40oz per sq foot. My bet is it's not going up.

You want a 1.5 pound plane to carry an additional 2.5 pounds of payload? You will be asking a lot of this airframe. Your wing does seem to have a very short chord and span to carry 4 pounds. Your wing area adds up to 231 sq inches or 1.6 sqft. This would give you a wing loading of 15 oz/sqft empty (very light and fliable) and 40 oz/sqft with your 2.5 lb payload (a brick with wings). Sure you can get it to fly with sufficient power and maintaining a pretty high airspeed. Then you may run into structural problems with a model this small. Try to get your wing loading not to exceed about 25-30 oz/sqft. You can increase the wing size or reduce the payload to accomplish this. To fly 4 pounds with a 30 oz/sqft wing loading you would need a wing with about 307 sq inches of surface area or 2.13 sqft. Increace the wing size to 6.5 inch chord and 48 inches and you'll be in there. I am also assuming your fusalage length is just the box up front and not the boom (This overall length should be included). For reasonable stability you will want at least a 36 inch fusalage (including the boom) but a longer tail moment will be more stable at about 40 inches. This is just a quick assesment, I hope it helps.

EDIT: I thought I should include the formula for calculating wing loading.

Wing loading = Flying weight ounces / (Chord inches x Span inches /144)

If i extend the wings to 50" span and chord of 8", and construct the plane with 4 equal pieces wings, will that be feasible? Like my original plan was 3 pcs wings. Im limited in terms of sizing.

You might want to give a little fuller explanation of just what it is you are trying to accomplish.

In addition to what the other guys have said, my first thought on seeing your drawing is "tail heavy". Unless you're using an unusually heavy power source (electric motor?), or your tail is uncommonly light, my gut says that your CG will wind up too far to the rear.

Also, are you using a squared-off back to your fuse pod? that creates a ton of drag. If you can find a way to taper the pod down to the boom, you'll get much better performance. Of course, this varies with airspeed, the higher the speed, the more pronounced effect this will be. At a low enough speed, it may not matter much. (for reference I've tried out the difference with a 2"x2" wide squared off fuse on a 55mph .15 powered plane. tapering the fuse made a big difference)

I think this same thread came up last week. Basically the same answers too.

To the OP: There is a alot of information available about RC airplane design. Some good stuff online, and lots of good stuff if you're willing to buy a book. If this is just for you to have an airplane to enjoy, then buying an ARF or RTF plane is the cheapest, safest, and easiest route to go. It would be smart to at least start with a proven design and learn flying before trying to design and build something from scratch.

<span class="Apple-style-span" style="font-family: 'Times New Roman'; font-size: medium; "><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; background-image: initial; background-repeat: initial; background-attachment: initial; -webkit-background-clip: initial; -webkit-background-origin: initial; background-color: rgb(255, 255, 255); font-family: Arial; font-size: 12px; background-position: initial initial; ">Thread locked to prevent original content from being deleted<div></div></div></span><span class="Apple-style-span" style="font-family: Arial; ">Ken</span>