22 AEROPLANE PERFORMANCE CALCULATIONS 



L is the lift of the wings in pounds. 



S is the wing area in square feet. 



R has been defined in Chapter I. 



L/D, k l , k^ax, and X have been defined in Chapter II. 



Now on our assumptions 



. . . (2) 



L- oo237^ J S(i-467V) 2 . . . (3) 



L = W . (4) 



L = \k imax . (5) 

 From equations (3), (4), and (5) 



V* = ' L 



00237(1 - 



i W 



where 



00237(1-467)' Xfc^S 



i W I 9 6W 



Ro. 



Vioo/ io,ooox 



.*. from equation (2) 



Q w 



(T) 



where 0= 4 (jS) 



Equations (i), (V), (a), (T), and (/3) are in such a form that a 

 tabular method can be conveniently applied to them (see Chapter 



XL). 



The values of L/D and k imax used above are of course the 

 corrected values taken from the wing characteristic. 



The above equations having been solved tabularly, we have 

 values of V and P for values of X from 'I to 1*0: these values of 

 V and P are the data required for plotting the performance curve 

 for standard density air under the assumptions of the First 

 Method. 



