skerlock

What is a acceptable wing loading for a 1/4 scale plane..My wing loading calculator says mine is at 30.4 oz. per sq. ft
Is that ok what is a good number..
span is = 78"
root cord = 17"
tip cord = 8"
weight = 12.9 lbs
wing area is 6.77 sq. ft.

thanks

Scott

Ollie

The wing loading and the maximum coefficient of lift of the airfoil determine the airspeed at which the plane will stall. the stall speed plus an adequate stall margin determine the safe landing approach speed. The wing loading and maximum coefficient of lift determine the minimum turning radius for a given angle of bank. The highly tapered wing planform means the plane will tip stall easily and adequate stall margin must be maintained in landing aproaches and turns if tip stalls are to be avoided.

The wing loading of 30.4 ounces per square foot is not unusual for scale models of the size you mention which means this is acceptable to a lot of modelers. However, the lower the wing loading the tighter it will turn and the slower it will land. How important slow landing and tight turning are to you will determine how acceptable this wing loading is to you.

qspilot

ollie,

You know your Aerodynamics. Are you a full scale pilot? I am but I still need a little help on wing loading. I keep hearing low wing loading helps 3D. Why don't the builder make than wing bigger too lower the wing loading? I am taking about 1/4 and larger Extra's, Edge's, etc...

Will the bigger wing and lower wing loading effect other flight performance?

Also my GP 1/4 Extra calls for the engine thrust washer to be 7" from the firewall. I can only get 6 1/2 with my BME 44 without using standoffs. Will this effect the flight performance?

Thanks,

Chris

Ollie

Chris,
To summarize my answer to your E-mail: Reducing weight benefits all flight modes by reducing both power loading and wing loading. This is the highest priority in the design and construction of a 3Dmodel.

rmh

Maybe this is what you were asking about:
The mfgrs are building the 1/4 scale jobs for 1.6 gas- 1.2 gas etc - for the newer modeler.
There are currently very few ARFS designed for your engine -
A really great setup for you would have a wing loading of 26 oz ft-
There just arn't any--.
How the model looks vs how it can really perform -in this size is th real criteria.
A scale model of 78 " span having about 1150-1200 " area - weighing 13 lbs would match your engine very well.
As you have probably seen - most of the 1/4 scale stuff - ends up with a 30 oz loading - too high for really fun stuff.
for real 3D stuff - abour 20/ 22 oz ft.
I am