12 
Example of Navigational Computation : 
Direction of flight line 
West-East and East-West 
Flight line spacing 
s = 8 100 m 
Air speed 
v e = 350 km p. h. = 97.3 m/sec. 
Wind incidence angle 
580 (in direction of turn) 
> (Measurements) 
Wind velocity 
85 km p.h. = 23.6 m/sec. 
Computation of turn : 
Wind component v W y (from wind computer) = 12.5 m/sec. 
Angle of crab 
„ „ „ Pi = 70 = 7 sec/t 0 
P2 — 7° — 3.5 sec/ 2 ° 
ft + ft = 140 = io.5 sec. 
2nd interpolation for 
s’ 6 535 m 
Turning angle of aircraft 
1800 + ft + ft = 1940 
From diagram for s = 
8 100m: tj + t 2 = 132 sec. 
114.5 sec. 
ti + t 2 + Pi + ft = 142.5 sec. 
125 sec. 
Wind displacement/! s = 
(*! + H + Pi + Pz\ ' v W y = 1 780 m 
1 560 m 
Flight line spacing s + 
As = 9 880 m 
8 095 m 
s’ = s — 0.88 • A s 
= 6 535 m 
(sufficient accuracy) 
with s' = 6 535 m from Diagram 6: 
^ -f- pi = 49 + 7 = 56 sec. 
t 2 + p 2 = 65.5 + 3.5 69 sec. j 
Computation of Course: 
Run 
West-East 
East-West 
Geographical course 
900 
2700 
Compass correction (from table) 
+ 10 30’ 
- 00 30’ 
Declination (map) 
- 30 30’ 
- 20 
Angle of crab 
- 70 
+ 70- 
Heading 
810 
2740 30’