Jim_Purcha

My Feedback: (8)

Question regarding wing loading on a model. I finished a scratch built F-18 from RCM plans. The plane is a 0.40 pusher prop design, and the plans call for a completed weight between 5~5.5 lbs. The plans state the wing area is 500 sq. inches. I'm at 5.5lbs now with landing gear, radio equipment, but no engine installed. Thinking of using an ST 0.51. With the engine, mount, muffler and pump I am adding 18oz to the back end of the model.My completed weight of the model would be6.5 lbsbefore flying. Any concerns?

Jim

All Day Dan

My Feedback: (5)

Jim, wih a finished weight of 6.5 pounds(104 ounces) and a wing area of 500 square inches(3.47 square feet) your wing loading is going to be 30 ounces per square foot. This is substantial comsidering the shape of the wing but still tolerable. Just keep your speed up on the approach. Dan.

Ram-bro

My Feedback: (101)

You may have to add weight up in the nose area to balance, also you have more wing area with the F18 than listed. It is a lifting body design.

Chad Veich

My Feedback: (60)

No sweat in my opinion.

Jim_Purcha

My Feedback: (8)

Thanks for the opinion fellows. I'll have to watch for this when it comes time to fly the plane. I have at least 4 months to think this through, have to wait for the snow to melt. The little we have could be gone in a couple of days at above zero degrees.

Jim

dhal22

Jim, was this the plane you were going use my .55 AX on?

Jim_Purcha

My Feedback: (8)

No, David I started this plane about 3 years back. I purchased a Bisson pitts muffler and extra back plate for a super tiger GS45 or 51. Didn't expect the plane to come out over weight. Too little painting experience and too much paint. Live and learn.

Jim

kenh3497

Sandpaper may be your friend.... [] That is, if push comes to shove.. You could remove 2 to 4 oz. of weight and repaint verrrry lightly to bring back the shine or buff like crazy. No good way out of this one. Go fly it and see what it's like before making a rash decision.

Ken

Jim_Purcha

My Feedback: (8)

Ken, that is the last thing I want to do. I'll fly it first. It was a challenge to mask and paint it the first time.

There was a lot of sanded balsa blocks and 3/16" balsa (sides)used in this design. The wings were also fully sheeted. The fins and stabalizers were 3/16" sheet. Next time (if there is a next time), open bays construction on the wings, 1/8" sides, ultrakote in stead of paint.

Jim

Bundubasher

Jim,
To put you in the picture - "floaters" like theMini Pulseetc have a wing loading of around 10 - 12 oz/ft2, in generalsport planes have wing loadings in the vicinity of15 - 18oz/ft2 .
You are at around 30oz/ft2. I have a Aviomodelli Piper Arrow II which is at 30 oz/ft2. It is a bit on the heavy side but flies and land ok - but that is with a straight wing and and a NACA 15 airfoil (if I'm not mistaken). You have a swept back and thinner wing - make sure you have around 50 m of runway - maybe more in the beginning. Once in the air, go up toa safe distance and fly slow - get to read the stall characteristics and recovery. Then apply it to your landings - you will probably have to come in a little hot,


Good luck
Bundu

Jim_Purcha

My Feedback: (8)

I remember it was a 40 AX. Have to get this plane in the air this summer.

What about your Blue Angel? Is it flown yet?

Jim

tdstaf

My Feedback: (11)

Any thing under 35 oz sq ft you should be good. I like my planes a little heavy they don't flit so much.