Time to PSR
= E x H Where: E = Fuel endurance: 3 hrs 10 mins
(3.17hrs)
(O + H)
H = Groundspeed home
O
= Groundspeed out
To find H
and O use CRP5 or similar:
Centre dot
on TAS, 140 kts, rotate to wind direction, 100°; come down from centre dot for
wind speed, 25 kts; mark end of wind vector at 115 kts.
Rotate to
outbound track (135º) under heading index; note drift 7°Stbd; rotate track to
drift; note drift now 6°Stbd; rotate track to drift; note drift still
6°Stbd. Required heading outbound will be 129° to track 135°; groundspeed
out, O = 119 kts
Rotate to
homebound track (315º) under heading index; note drift 5°Port; rotate track to
drift; note drift now 6°Port; rotate track to drift; note drift still
6°Port. Required heading homebound will be 321° to track 135°;
groundspeed home, H = 159 kts
Time to fly out = 3.17 x 159 =
1.81 hr = 1 hr 49 mins
(119 + 159)