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## Main Question or Discussion Point

Hi all,

I'm having trouble with the power required formula for steady level flight.

Here's the formula:

P

I'm using this for a small indoor RC fixed wing. The values I'm using are as follows:

Weight, W = 0.3924N

Wing Area, S = 0.073 m^2

Density, ρ = 1.226 kg/m^3

Zero lift drag, C

Span efficiency, ε = 0.9

Aspect Ratio, A = 15

These values are giving me a power required of 0.051 W, which is almost exactly 1000 times less than what I know the electric motor uses, since it holds SLF at half throttle and the max power rating for the motor is 100W.

Where am I going wrong? I know I've gotten my units mixed up but I can't work out where. Help!

:/

I'm having trouble with the power required formula for steady level flight.

Here's the formula:

P

_{req}= 4/3*W*sqrt(W/S*2/ρ*sqrt(3*C_{D0}/(π*ε*A)))I'm using this for a small indoor RC fixed wing. The values I'm using are as follows:

Weight, W = 0.3924N

Wing Area, S = 0.073 m^2

Density, ρ = 1.226 kg/m^3

Zero lift drag, C

_{D0}= 0.03Span efficiency, ε = 0.9

Aspect Ratio, A = 15

These values are giving me a power required of 0.051 W, which is almost exactly 1000 times less than what I know the electric motor uses, since it holds SLF at half throttle and the max power rating for the motor is 100W.

Where am I going wrong? I know I've gotten my units mixed up but I can't work out where. Help!

:/