NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: David Pike
Date: 2020 Dec 27, 04:12 -0800
Quiz No2
Our pilot from yesterday decided he enjoyed his flight so much he’s decided to do the same again today. His airspeed speed will still be 150 kts; he’ll still have three hours safe endurance; and his outbound track will still be to the east. However, today, the forecast wind velocity is 30kts from 030 degrees. Calculate what his heading should be if he is to track to the east; after how many minutes he must turn around to track back west, how far east he will have travelled; and what his heading home must be.
Solution to yesterday’s Quiz
Let distance east = R. Groundspeed out =Go = 150-30=120kts.
Groundspeed home = Gh=150+30=180kts. Time out = To = R/120. Time home = Th = R/180
Endurance = E = 3hrs = To + Th = R/120+R/180 = R (120 + 180)/120x180 = 300R/21600
Therefore R=3x21600/300 = 216nm and To = 60x216/120 = 108minutes
