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9º Rule p.141

  • oscarmiike
  • Topic Author

oscarmiike created the topic: 9º Rule p.141

Hi,

I was wondering if someone could help me to understand where the 6.66 number comes from. I don't pretend to be a genius when it comes to mathematics so forgive me if it's something obvious.

Cheers,
OM

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  • Bonanza

Bonanza replied the topic: 9º Rule p.141

Hi OM
6.66 comes from dividing 60 by 9 degrees. It is a reverse engineering of the 1 in 60 rule.
The rule assumes that if your 9nm off FPT after 60nm you you have 9 degrees of drift.
To help with the math, In Bobs example he says you would have to fly 600nm at 9 degrees off track before you would be at the 90nm limit of coverage, and this is because you would be 90nm off track
Using the 1 in 60 rule 90 miles off track after 600nm would be 9 degrees.
I hope that helped!
Cheers
Ben
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  • oscarmiike
  • Topic Author

oscarmiike replied the topic: 9º Rule p.141

Perfect, thanks Bonanza. I think that was actually mentioned on the previous page :S I've been looking at this text book too long.

Many thanks,
OM.
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