164 



CHAPTER XIX. 



AIR PERFORMANCE. 



I. GLIDING FLIGHT. 



Example (l). Landing Speed on Glide: First Method. 



Applying this method to the machine dealt with in examples 

 (i) to (4), Chapter XVI II., page 155, we have 

 W = 5700, 

 S = 695, 



L ** = '590, 



1 1 96 x 5700 



' V = A/695 x -590 == 52 ' 2 miles per hour 

 While at an altitude of, say, I 5,000 feet, where a = '630, 



= V-z I96 * 57 - = 65-8 miles per hour. 

 1 -630 x 695 x -590 



Example (2). Landing Speed on Glide: Second Method. 

 Again with the same machine 

 W = 5700, 



S = 695, 

 L * = '590, 



/- 14, 



/' *= 16-1, 



c = 7, 

 k c = -276 (for X = I -o), 



... V- Jl I96 * 5 / X I4 - - = 51-8 miles per 

 \695 x -590(16-1 - 7 x -276) 



and for the gliding landing speed in summer on a plateau in 

 Mexico 6,000 feet above sea-level, allowing also for the relative 

 air density correction (see footnote page 117) of 4,450 feet, 

 we have to take a corresponding to 10,450 feet, i.e. a = 725. 



.-- V - V: 



196 x 5700 x 14 



725 x 695 x -590(16-1 - 7 x -276) 

 60-9 miles per hour. 



