jnaarnold

My Feedback: (4)

I have a 1/12 Hawker Typhoon from waverly rc. From my calculations, I have 336 sq. in. of wings. The plane weighs 4lbs 7.5 ounces..I know-heavy for this type of plane but I had to add a lot of lead to the nose to get it to balance. Question, is a wing loading of 30.21 horrible for this plane? It has an OS .46 LA on it, with an 11x4 APC prop. I am going to try and re-evaluate things..So far everything is as far forward as it will go. This plane has to be hand launched so I feel I need the wing loading way down....thanks again.

jettstarblue

That's a mighty high wing loading for one that size! Should be nearer to 16-20.
I know it's built, but have you considered re-doing the engine mount, so the engine sits a little further out? May require a cowl re-do, but so will a bad hand launch.

mulligan

It's a bit heavy, but I wouldn't mind flying it at all. It'll take-off and land a bit fast, but it'll be a little bit more solid in the air.

According to your profile, this plane would seem to be (forgive me) a bit of a challenge for you- you might want to let a local expert pilot that you trust take her up first, so you can get a feel for it in the air first.

In addition to Jett's suggestion, you might also, after test flying, decide you don't need so much nose weight, and that the CG can be a little farther back than recommended.

Stick Jammer

The specs on that plane state "Up to 3 lbs". They also call for a .15 -.26 engine. Something has to be very wrong if you've got a .46 installed and still had to add a lot of lead up front. If their specs are right and the plane should weigh 3 lbs. that would be a wing loading of about 20 ounces per sq. ft. I could be wrong, but I think your first flight is gonna be very short.

jnaarnold

My Feedback: (4)

My first flight was very short.....this thing took a ton of weight, incl uding a .46 in the nose to balance correctly.

Stick Jammer

Hope it wasn't too bad. Maybe you should contact Waverly RC for their input as to why your's came out so heavy. They are not providing very reasonable specs if you built it correctly. Your wing loading is 50% higher than it should be. That's a huge amount on that size of an aircraft.

jnaarnold

My Feedback: (4)

I did glass and paint the wing...and painted the fuse.....that might be where the weight is......??

Stick Jammer

You did an awesome job, it's a great looking little plane. Unfortunately a plane that size isn't going to handle a 50% weight gain very well.

J_R

With that weight and area the stall speed is going to be about 30 mph. With that prop and engine, it's going to have a top speed of about 50. You better throw it hard and level.

There is an old phrase that says you can balance a brick but you can't make it roll. The newer version is you can make a brick fly, but, you can't make it 3D. Your about to prove it.

Keep in mind that when you land... keep the speed up. When the speed drops below 30 it's probably going to stall, or tip stall and... prang.

jnaarnold

My Feedback: (4)

How did you come up with that figure of stall speed? Would love to learn how to equate that for future use. NOW, back to the subject, how can I lighten this plane up? I need to shed about 1 pound, I am up to all sugesstions and will probably post as a post of its own, but for now feel free to reply here...thanks

J_R

Check this page out. It contains several calculators... including stall speed. The instructions on the page explain the logic used in the calculators.

http://pages.sbcglobal.net/limeybob/

The first thing I would do is to evaluate the CG. I would put it at 33% (if you are very experienced, start at 35%) of the MAC and adjust from there. I would give serious consideration to a .25 engine. Move all the weight forward. Battery, servos, Rx. Reduce the weight in the rear. Us light weight push rods. A smaller tank in the front, for the smaller engine means more room up front for the bat, servos and Rx. A 4 oz tank should work for a 25 where you need at least 6oz and probably 8 oz for the .40. Look at everything. If the wheels are rubber, replace with foam. Reduce the tail wheel weight, maybe foam and a smaller diameter.

It looks like it is too late to consider paint, but, you might have to sand all the paint off the tail and be more light handed.