68 AEROPLANE PERFORMANCE CALCULATIONS 

 corresponding to equation (5), page 25 ; and 



(where T' is the T of the previous paragraph divided by 32*2), 

 corresponding to equation (6), page 25. 



Put B = (I + V? - I = b(b + 2) . . (B) 

 Then we have from equations (i), (2), and (4), using equation 

 (3) to eliminate L 





W/V 2 = -0051X^8 + S') . . (6) 



and B = IQ5 T (7) 



2 



... W/V 2 = -0051X^5 + l from (6) and (7) 



W - 367 H^ S>T/ 



... V 2 = _ - _ .... (V 2 > 



From equations (7) and (V 2 ) we have 

 I0 5 T' x 



I -39^ W - 367 



- aS' 

 where a = 3 6 7X L ^T' (a) 



Now V 2 = 



W/V 2 = 



L/D == L/D(Wa? - aS') 



K' = aSRi + RI + ^2 T 



This equation enables us to find K' for a range of values of X 

 and thus, by plotting, to find and use its minimum value for flying. 



