Wind correction for GC steering
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Whenever I see discussions like this, I second-guess my intelligence and ability to get a private pilot license……
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Its easier than it looks Jinro, just go for it.
Freferf, the other thing is that if you have any wind, on a long leg flying ‘straight’ using the AP, your heading will graudually increase or decrease as you approach the STPT. This was what ticked me onto it originally.
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The picture was enough. It doesn’t look right. What I said should be how it is but that picture shows otherwise. Diamond and tadpole should be directly above/below.
sorry but i dont see anything wrong in that picture….
can someone explain to me ?
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Okay, the current setup in BMS is that aligning the FPM with the GCSC will cause the nose to be pointed directly at the STPT, rather than causing the FPM to be pointed at the STPT. i.e. in BMS, the GCSC points the aircraft to the correct BEARING, not the correct TRACK.
excerpts from the -34 above indicate that in at least one OFP, this is not correct behavior.
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sorry but i think there is a misunderstanding here.
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The DIAMOND marks the physical location where the AC shall fly over : DO YOU AGREE ?
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The FPM reprensents the velocity vector, in other words this is where the AC is flying to , taking into account wind and turbulence or even beta side slip : DO YOU AGREE ?
1 + 2 = to fly over the physical waypoint location , the FPM SHALL be aligned with the DIAMOND
the GCSC is the marker line on the heading tape, correct ? (i think it is , i am no specialist here with acronyms)
to me the GCSC shall indicat the heading where the noze shall be put in order that the FPM be align with diamond, simply because when there is a lot of drift , fpm can not be seen , so the only way to know is to indicate the pilot the heading relatively to the NOZE => GCSC
so in your picture the GCSC should be around 29 / 30 (i.e. on the right…) and pilot should align his noze to it
according to my memories , this is exactly what BMS does and i dont understand how it could work otherwise ?
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JP : the issue is that when you align the tadpole (“têtard”) inside the FPM, your FPM is not aligned with the waypoint, the nose is.
Edit : that is what you meant with GCSC, Blu3wolf, right ? Because I couldnt find this acronym in the Dash-1. For me it is always called the tadpole.
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JP : the issue is that when you align the tadpole (“têtard”) inside the FPM, your FPM is not aligned with the waypoint, the nose is.
Edit : that is what you meant with GCSC, Blu3wolf, right ? Because I couldnt find this acronym in the Dash-1. For me it is always called the tadpole.
haaa…if GCSC is the tadpole i.e. the small circle in the hud etc…then there is indeed a bug…when correct heading is taken , diamond , tadpole and fpm shall be aligned and the indicator on the heading tape shall indicate the nose heading then (because you can’t see neither fpm, tadpole or diamond in extreme situations).
=> Bugtracker
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To take wind into account just align fpm and diamond
Real pilot to confirm
Correct … and in this pic: https://www.benchmarksims.org/forum/attachment.php?attachmentid=15748&d=1365459294
… if the pilot maintain present HEADING, he will not (should not) overfly the way point but pass left of it. So basicaly, according to the pic, the Tadpole isn’t guiding the jet on the waypoint (track) but just give a steering cue to put the nose on it (heading)
No more Falcon on my computers, so I can’t try, but will do it as soon as I have it back.
I think it is the way it is working in real. The GCSC does not take wind
I am not sure. (?) IMO, the tadpole should work as a flight director in “direct to” mode. (need to be crosschecked in -34)
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Correct … and in this pic: https://www.benchmarksims.org/forum/attachment.php?attachmentid=15748&d=1365459294
… if the pilot maintain present HEADING, he will not (should not) overfly the way point but pass left of it. So basicaly, according to the pic, the Tadpole isn’t guiding the jet on the waypoint (track) but just give a steering cue to put the nose on it (heading)
No more Falcon on my computers, so I can’t try, but will do it as soon as I have it back.
I am not sure. (?) IMO, the tadpole should work as a flight director in “direct to” mode.
TBH DJ what you are saying has no sense.
tadpole should guide the AC to the waypoint !!! so when everything is fine tadpole / fpm and diamond aligned.
else tadpole is useless:!
BUG for me
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Looks good to me. strong crosswind (29 knots from the right (28 degrees off)) ‘blows’ the fpm to the left. the tadpole is inclined to the right (1pixel - hard to see) and indicates that the direction needs to be adjusted.
or does puting the fpm over the tadpole always (crosswind???) lead to the steerpoint in the real jet?
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The fact that the tadpole is on the same level as the FPM, and not the guncross for example, is in JP’s favor, IMO.
The tadpole should be an indicator of where to go to overfly the waypoint : ie, putting the FPM on it means you are goind directly toward the waypoint regardless of drift and where is your nose pointed at.
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The fact that the tadpole is on the same level as the FPM, and not the guncross for example, is in JP’s favor, IMO.
The tadpole should be an indicator of where to go to overfly the waypoint : ie, putting the FPM on it means you are goind directly toward the waypoint regardless of drift and where is your nose pointed at.
dont agree
Tadpole is the indicator to say right or left when diamond not visible
Once diamond is visible, Tadpole useless, just put fpm on diamond
And just in case fpm and tadpole are no more visible, then the marke ron heading tape to be used
it seems here that the tadpole is not indicating to adjust to the right …to be checked,
At the end , 3 tadpole / fpm / diamond shall be aligned
on the posted picture, Tadpole is saying : " no need to change course your fpm is right to the place to go to waypoint " which is NOT TRUE => BUG
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At the end , 3 tadpole / fpm / diamond shall be aligned
on the posted picture, Tadpole is saying : " no need to change course your fpm is right to the place to go to waypoint " which is NOT TRUE => BUG
No arguments here, that is exactly what I meant
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I never heard of this stuff or know how to turn it on. The Great Circle navigation has to do with flying a shorter arc course rather than flying a straight latitude course. The arc course is shorter because the earth is a sphere and the arc course is a (straight) line of sight track and the straight latitude course is actually a longer curve track. I thought that F4 was Earth was modeled as a plane not a sphere. The “earth is flat” model make other things hard or impossible to model, I would thing.
what am I missing?
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I never heard of this stuff or know how to turn it on. The Great Circle navigation has to do with flying a shorter arc course rather than flying a straight latitude course. The arc course is shorter because the earth is a sphere and the arc course is a (straight) line of sight track and the straight latitude course is actually a longer curve track. I thought that F4 was Earth was modeled as a plane not a sphere. The “earth is flat” model make other things hard or impossible to model, I would thing.
what am I missing?
caper this is ANOTHER thing
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caper this is ANOTHER thing
If GC nav was model on a plane, then the track would be longer and the arc would appear to be off course….wind or no wind.
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TBH DJ what you are saying has no sense.
tadpole should guide the AC to the waypoint !!! so when everything is fine tadpole / fpm and diamond aligned.
else tadpole is useless:!
BUG for me
Agree!
However, on some a/c (mine) in some case, the “tadpole” (flight director equivalent) can give you a steering command to stay on your “TRACK” … what I mean about “track” here, is the route defined between two waypoints. So, it won’t give you command to steer direct to the WPT, but to make you intercepting the “route/track” between the two WPT, and then, one back on route, give you a command to apply the correct drift. (same behavior than the course deviation needle of the HSI, or the LOC of the ILS. … in F-16, it would be equivalent to the CMD STEERING CUE in HUD when performing an ILS)
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Whatever, IMO, you re correct, and the tadpole is should act as in “direct to”, hence, the three symbols (Waypoint diamond, tadpole and FPM) should be overlapping when you are on the proper route.
So, I would say that I agree … probably a bug here.
The fact that the tadpole is on the same level as the FPM, and not the guncross for example, is in JP’s favor, IMO.
The tadpole should be an indicator of where to go to overfly the waypoint : ie, putting the FPM on it means you are goind directly toward the waypoint regardless of drift and where is your nose pointed at.
Agree.
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Its easier than it looks Jinro, just go for it.
Freferf, the other thing is that if you have any wind, on a long leg flying ‘straight’ using the AP, your heading will graudually increase or decrease as you approach the STPT. This was what ticked me onto it originally.
haaa…if GCSC is the tadpole
Yes, the other thing “captain’s bars” on the heading tape you see on many airplanes is not on the F-16 except in ILS mode for landing, at least the OFP this manual is for. However there is a indication on the corner of the MFD like a capital “W” for steering if FPM off HUD. Also if drift c/o is on you can always put FPM on GCSC. Also if you put ground speed option on HUD heading tape = ground track tape.
Agree!
However, on some a/c (mine) in some case, the “tadpole” (flight director equivalent) can give you a steering command to stay on your “TRACK”
Yes, many aircraft have a concept of steering intercept to desired course line. F-16 does this to command 45-degree intercept to ILS LOC.
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sorry but i think there is a misunderstanding here.
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The DIAMOND marks the physical location where the AC shall fly over : DO YOU AGREE ?
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The FPM reprensents the velocity vector, in other words this is where the AC is flying to , taking into account wind and turbulence or even beta side slip : DO YOU AGREE ?
1 + 2 = to fly over the physical waypoint location , the FPM SHALL be aligned with the DIAMOND
the GCSC is the marker line on the heading tape, correct ? (i think it is , i am no specialist here with acronyms)
to me the GCSC shall indicat the heading where the noze shall be put in order that the FPM be align with diamond, simply because when there is a lot of drift , fpm can not be seen , so the only way to know is to indicate the pilot the heading relatively to the NOZE => GCSC
so in your picture the GCSC should be around 29 / 30 (i.e. on the right…) and pilot should align his noze to it
according to my memories , this is exactly what BMS does and i dont understand how it could work otherwise ?
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The STPT DIAMOND marks the location of the STPT - it is what we intend the aircraft to overfly. So far, so good.
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the FPM represents the direction of the velocity vector, i.e. where the airplane is flying to, taking into account wind, turbulence, alpha, beta, etc - all good.
ergo, to fly over the STPT DIAMOND, the FPM needs to be aligned in azimuth with the DIAMOND. All hunky dory so far!
The GCSC is my own abbreviation for the Great Circle Steering Cue (or tadpole). I don’t think its found in the manual.
The tick mark on the GCSC indicates the direction the plane needs to turn to find the diamond, and is used for coarse steering. The circle aligns with the FPM when your ground track (track - in the sense that track is heading corrected for wind - so your ground track in this sense is EQUAL to the azimuth of the FPM) is the same as the required ground track to overfly the STPT DIAMOND. The circle is used for fine steering.
What I think you have all concluded, and am hoping you can confirm, is that the FPM and the STPT diamond should coincide in azimuth, when the Great Circle Steering Cue is aligned with the FPM. The nose should point upwind of the STPT DIAMOND.
Instead, what happens in BMS is that the nose points directly to the STPT diamond.
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