Small nav Q
Thread Starter
Joined: Apr 2000
Posts: 294
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From: West Midlands, UK.
Small nav Q
I would be grateful for an explanation as to the solution of the following. Thank you for any help in advance.
Q: Given: Grivation 6W, Variation 10W, what is the value of convergence?
a) 4E
b) 16W
c) 16E
d) 4W
Q: Given: Grivation 6W, Variation 10W, what is the value of convergence?
a) 4E
b) 16W
c) 16E
d) 4W
Joined: May 1999
Posts: 1,846
Likes: 4
From: Bristol, England
preliminary definitions:
Variation. The difference between magnetic and true direction. Whichever is larger can be found using the rhyme:
Variation East Magnetic Least, Variation West Magnetic Best
Convergence. The difference between True Direction and Grid (gyro) direction. Whichever is larger can be found using the rhyme:
Convergence East True Track Least, Convergence West True Track Best
Grivation. The algebraic sum of variation and convergence. Applied using:
Grivation West Magnetic best, Grivation East Magnetic Least
So convergence must be Grivation - Variation = 6W - 10W = - (4W) = 4E
(last time I heard of grivation being used was on RAF VC10s in the 1980s)
Variation. The difference between magnetic and true direction. Whichever is larger can be found using the rhyme:
Variation East Magnetic Least, Variation West Magnetic Best
Convergence. The difference between True Direction and Grid (gyro) direction. Whichever is larger can be found using the rhyme:
Convergence East True Track Least, Convergence West True Track Best
Grivation. The algebraic sum of variation and convergence. Applied using:
Grivation West Magnetic best, Grivation East Magnetic Least
So convergence must be Grivation - Variation = 6W - 10W = - (4W) = 4E
(last time I heard of grivation being used was on RAF VC10s in the 1980s)
