Wind correction for GC steering
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I can’t really tell but is everyone on the same page? Without the -34 I know when you put the FPM on the tadpole it does not always align with the steerpoint diamond in azimuth.
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with DRIFT C/O in NORM, shouldnt the FPM, tadpole and STPT diamond all be aligned in azimuth?
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with DRIFT C/O in NORM, shouldnt the FPM, tadpole and STPT diamond all be aligned in azimuth?
I don’t believe so but I haven’t played with it enough STS to say for sure. When I get a chance I will mess with it. DCO should only affect where the FPM is. If you are not corrected for winds then you are just homing to the point. The tadpole and steerpoint have to do with the route flown.
The way I see it there are 4 ways to fly:
- DCO - OFF and FPM on tadpole
- DCO - ON and FPM on tadpole
- DCO - OFF and FPM on steerpoint diamond
- DCO - ON and FPM on steerpoint diamond
With (1) being the best.
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And here I naively thought 1 and 3 were identical :S
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Slightly OT but related - what does the tail on Herm the Sperm represent? Looked in the -1 but could find nothing.
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you would need to look in the -34 to get an answer, not the -1.
The tail is roll stabilised to the wings, and points to the heading towards the STPT diamond.
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GCSC tail shows “relative bearing” which would be the difference of aircraft heading and azimuth to destination. It’s not a given that the manual expresses everything absolutely 100% accurately to the smallest detail. It can favor concise and functional approximation for “good enough for the stick jockey” over "well technically it’s this vector minus this vector sourced from this data stream "etc. However if the text is taken literally then it’s relative bearing. Example as follows: destination is 090, true flight path heading is 090, GC steering says fly heading 085 due to wind from north, airplane heading is 085, GC steering error is zero. In this case the relative bearing of destination is 005 degrees right. Airplane heading is 085, true bearing to destination is 090, that’s a relative bearing of 5 degrees right. Taken by exact wording the GCSC tail should show a 5 degree angle to the right despite the FPM being on the GCSC (no steering error).
Diamond I don’t think is placed using the most exact math like GC cue is.
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GCSC tail shows “relative bearing” which would be the difference of aircraft heading and azimuth to destination. It’s not a given that the manual expresses everything absolutely 100% accurately to the smallest detail. It can favor concise and functional approximation for “good enough for the stick jockey” over "well technically it’s this vector minus this vector sourced from this data stream "etc. However if the text is taken literally then it’s relative bearing. Example as follows: destination is 090, true flight path heading is 090, GC steering says fly heading 085 due to wind from north, airplane heading is 085, GC steering error is zero. In this case the relative bearing of destination is 005 degrees right. Airplane heading is 085, true bearing to destination is 090, that’s a relative bearing of 5 degrees right. Taken by exact wording the GCSC tail should show a 5 degree angle to the right despite the FPM being on the GCSC (no steering error).
Diamond I don’t think is placed using the most exact math like GC cue is.
The GCSC knows nothing about the wind. The only thing affected is the displacement of the FPM for wind which is determined by the DCO switch.
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Slightly OT but related - what does the tail on Herm the Sperm represent? Looked in the -1 but could find nothing.
Think of it like the HSI - if you are steering directly at the steerpoint, it points straight up. If not, it’s telling you which way to turn and by how much.