Jump to content
Sign in to follow this  
electron

wing area of a bi-plane

Recommended Posts

some one know if the added surface area of a bi-plane

is truely supportive of the extra wing loading

i want to support payload and i want light wing loading is a bi plane the

logical answer?

thanks :blink:

sky cam electron

Share this post


Link to post
Share on other sites

YES, it maybe the answer you are looking for. I have used a biplane in very tight places where slow speed and tight turning was needed above ultimate duration.

I think from memory that 2 wings when used as a biplane equal about 1.5 wings and you need to mount them not closer than 2 cord lengths apart if you can help it.

Thats the basics but it can get very involved if you like to argue the t***!

Let us know how you get on.

Terry

UK

Share this post


Link to post
Share on other sites

From my experience, bi-planes tend to have a lot of drag. Ever have to bring one in with a dead stick? They sink like rocks!

Personally I don't think they would make a good plane for any payload.

A trainer is a much better bet. I've put 4 pounds in my 40 size trainer.

Admittedly it also became a sinker... but it still flew quite well.

Also the flat bottom and dyhedral in the wing give it some nice qualities for autopilots and RPV'ing.

I've also use a Modeltech Cessna 182 model... I fly it with 10% flaps with a heavy load in it and it does quite well.

My main "Carrying" machine is a Senior Telemater. It can handle a lot of weight, but considering it's a kit (not ARF) and the flight charateristics are only so so, I don't think I would bother with one again. I would simply look for a 60 size trainer ARF.

Edited by mikep

Share this post


Link to post
Share on other sites

Mikep,

I'm kind of a bipe nut. It has been my experience that Bipes tend to carry alot of parasite drag which makes the excellent candidates for radical aerobatics -- downline braking is incredible. Thus the tendency to fall out of the air like a brick.

There are a few things you can do to improve the parasite drag situation though. First, try to build it out without flying wires. The flying wires tend to create turbulence in the decalage area and reduce the lift of the upper wing. Also, a slight amount of negative incedence on the upper wing (about 1-2 degrees) also causes the pressure between the upper and lower wing to be reduced making the wing area more effective. Finally, if you must use a bipe choose a model with a stagger configuration.

Some candidates that I have found to be have these characteristics include the Waco, Great Lakes, and Hog. Stay away from the Ultimate, Pitts, Weeks, and Stearman if you want payload.

If you are looking for a good ARF trainer that does a great job of carrying payload. Try the Frontier Senior ARF. It is built very light and and a .91 OS or Saito 100 will pull this thing all over the sky. I have used one as a paintball carpet bomber. You can pretty much fill up the fuselage with paintballs and the thing just keeps flying.

Robert

Share this post


Link to post
Share on other sites

Put a bigger tail on that telemaster and it will fly much better. I used to have one of the big ones and that's what I did and I flew the wings off it till it went deadstick into that powerline.......... :blink:

Share this post


Link to post
Share on other sites

Aspect Ratio ( the w.s. divided by the chord) is very important in calculating lift.

If we had to wings that would fit on the one airplane.....and say the area was 1000 sq in in both wings but one wing had a chord of 10 in and a w.s. of 100 in while the other wing had a chord of 15 in. and a w.s. of 66.6 in which would give you more lift? I use the absurb to make a point.

The 100" span with chord of 10 " would give much more lift than the 66.6 in span and a chord of 15 in. Of course Reynold's Numbers do factor in. That means air speed, etc. So if both of those wings flew at thew same speed ( say 40 MPH) the one with the higher Aspect Ratio will lift more.

The 100" wing had an A.R. of 10 and the 66.6 " wing had an A.R. of 4.4! Just a little thought. The A.R. of a piper J-3 is about 7 to 1 or 7.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×