- Reaction score
- 13,561
- Points
- 1,010
aesop081 said:Hmmmmmmm,
Variation: Angular difference between TRUE north and MAGNETIC north
Deviation: Angular difference between MAGNETIC north and COMPASS north
ooops...nav exam passed....must flush this to make room for curve-of- pursuit homings !!!
What the heck is TVDMC ?
TVMDC- "True Vampires Make Dull Company". It is a memory aide to help out when you are converting True bearings or headings to Compass headings or bearings. The order is:
1. Take a heading in degrees True
2. Apply Variation (in the case of Victoria, BC it is 20E, so you subtract 20 degrees)
3. Add or subtract your compass Deviation (found either written on your compass card by doing a True heading check with a sextant- in the old days)
4. You are now left with a Magnetic Heading you can fly
5. On some aircraft, there may be a compass Correction of a degree or two that also has to be applied, if you are truly anal, which then leaves you with a Compass heading. It doesn't come up a bunch in Sea Kings (ie never- our kit is not that good).
Cheers.