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Radio-Magnetic Indicator [RMI]
scanwinder created the topic: Radio-Magnetic Indicator [RMI]
I'm just going through the CPL navigation book and I don't understand the RMI example on page 5.23:
You have maintained a heading of 070°M since passing over an NDB. The tail of RMI needle indicated 055°M, also constant. The FPT is 080°M. You decide on a 30° intercept of the FPT.
The answers are:
Intercept HDG: 110°M
HDG to maintain FPT = 095°M
Drift = 15L
I understand that drift is 15°L as it should be difference between the Needle and the heading (070°-055°). And I understand the heading to maintain FPT is 095°(The FPT + 15° to compensate for drift). But I can't see where the 110°M for the intercept heading comes from - I would have thought to intercept at 30° I would need to add 30° to the heading to maintain FPT, which would be 125°M.
Does anyone know where the intercept heading of 110°M comes from?
Mister W replied the topic: Radio-Magnetic Indicator [RMI]
The 110° is the heading you will fly so you can intercept your FPT of 080° at a 30°angle.
When intercepting, you don't really need to compensate for wind too much. The only effect the wind has while intercepting will be how long timewise and how far distantwise it takes for you to reach your FPT so you do need to be aware it.