I recently bought a KMP Extra 300L for my third plane. I was told it has a very high wing loading and that I would have to land at a reasonably faster speed. I intend to put an OS 61 on it, would this decrease the wing loading considering it is meant for a .46? On a side note, would this pane be able to do some 3D with a 61 on it?

Thanks for your help,

Jack

Increasing the weight of the airplane will increase the wing loading.

Dennis

Wing loading is a functin of the completed weight (in ounces)(ready to fly), in relationship to the wing area (in square feet). The size of the engine has nothing to do with this unit of measure other than the raw weight of the engine. I would think that those who said that the wing loading of this model requires significantly higher landing speeds were those who had found thid model to require more work than they were capable of performing to complete it's construction. I have not ever owned a KMP product, but I know several people who have. All the owners say that the models require a little more work than does the mainstream ARF, but they are actually very good models. Perhaps someone else has done this model, and can better tell you.

Bill, AMA 4720
WACO Brotherhood #1

Since a .61weighs more than a .46 and if you increase the size of the fuel tank thereby increasing fuel weight, your wing loading will increase. As the fuel burns off, that weight will decrease. IMOH, a good flying model should have a wing loading not greater than 23-25 oz/sqin. You can calculate wing loading by dividing the gross weight (wet or dry) in ounces by the wing area. As in full scale aircraft, the ambient temperature will affect performance also, although not an issue in Ohio this time of year.

You'll find most double taper wings will have a higher wing loading and need a touch more speed to land
but there not too bad as this is your third plane you should be fine, if you like to float in on landing may I suggest you break that habit before you fly the extra

The shape (planform) of a wing has absolutely no bearing on wing loading.

It is a function of only airplane weight versus wing area.

Nothing more, nothing less.

Funny story.

Our local hobby dealer said that a modeler came in to the shop to tell how he reduced the weight of his heavy plane.

He cut 6" off each wing tip!

Ken

Fly a prop jet a few times and that Extra will seemto float like a balloon.

ok after doing some checking KMP does not make an extra 300l in any size.However CMP does.they have at least 3 sizes.the specs for the .50 size are.
Wingspan
1430mm Length
1270mm Weight
2.85~2.95 kg Wing Loading
92~95 dm/2 Airfoil
Naca 0014 Wing Area
30.8 dm/2
in english units that is about 3.84 sq ft and 104 oz for a wing loading of 27 oz/sq ft.also notice the airfoil.it is 14 % thick so a bit thinner than sport planes that are 15-18 % thick.this wing loading is more in the scale plane range than aerobatic.to get this in an acceptable range the weight would have to be around 4 pounds empty.

All this talk about wing loading makes no sense, you need to also look at the size of the plane. A 100 cc gasser would feel like a floater with 35 oz wing loading. A 40 sized low wing will be a flying brick with that sort of wing loading.

aerowoof - 92-95 dm/2 is about 30 oz wing loading.

Exactly. Don't get scared of the wing loading numbers. Most of those aerobatic types or 3d will float pretty good if you fly em right but propjets or similar can drop like a brick no matter how hard you try. YOu bring your Extra in on a normal 8-10 degree angle with good throttle management and you'll be just fine.

I got a Global Raven 40, wing loading is kinda high ... about 30-32 oz. Everyone told me she is not flyable. She will stall on take off, stall on landing, snap on a loop etc etc etc. So many people in RCU and my local flying field said the same thing. I decided to fly her, to my surprise she was a good plane to fly. I am not a pro but sometimes you need to know what to do to 'tame' a plane.

You can make her slightly nose heavy, have less throw ... create some 'wash out' by raising the ailerons on either side by 1/8" etc. Using a bigger prop to get more wash ... I loved that plane.

KMP does or did make a 300L, it says on the box that it has 25 oz/sq ft, and it may increase slightly because I have decided to put a .61 on it.