AIR PERFORMANCE 



169 



In this table the values of V and tan <I> for v = o are filled 

 in from the immediately preceding piece of work : the remainder 

 from the minima of the curves plotted on page 167, these curves 

 being plotted from the data in the big table on page 1 66. 



The values of o- for the altitudes in the table are 740, "5 30, 

 ^368, and -242. The last four columns are filled up from the 



v 



formula v = =. 

 v/o- 



V and tan <l> are then plotted on a wind speed base on 

 page 1 68. 



If desired they can be cross plotted on an altitude base by 

 taking vertical sections at even intervals of wind speed. 



II. FULL POWER FLIGHT. 



Example (5). Top Speed. Take the curves on page 170. 

 The P curve is taken from example (i), Chapter XVI II., page 

 155, and the P T and P R curves are taken from example (3), 

 Chapter XVII., page 153. 



In this case the intersection of the P curve with the P R curve 

 is lower than the intersection of the P curve with the P T curve. 

 The first-mentioned intersection must therefore be taken : it 

 gives- 

 top speed = 1 02 miles per hour. 



For top speed at an altitude the procedure is the same, but 

 the machine and propeller performance curves must be plotted 

 for the altitude. 



Example (6). Rate of Climb (First Approximation). Using 

 the same curves as in example (5) and noting that W = 5700 

 for the machine they refer to, if we only require the maximum 



