Issue with To/From indicator in HSI ?
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Hi guys,
currently I’m working my way through TACAN navigation and the To/From indicator in the HSI keeps getting me confused, maybe because of a possible bug.Short version:
The To/From indicator in this picture with course 359 doesn’t make sense to me.Long version:
Sorry, this is a bit lengthy, but I want to be precise.My understanding is, if the To/From indicator points to the same side as the course selector arrow, it means “TO”, and if it points behind to the side opposite the course selector arrow, it means “FROM”.
I’m in the Israel theater, 35 miles southwest from Ramon. When I took the screenshots, I used Shift-P, to freeze the simulation and therefore all my screenshots are from exactly the same position.
Here you see , that the course selector arrow is at 213 and the To/From indicator is on the opposite side, which means “FROM”. So I’m on radial 213 outbound, 35 miles southwest from Ramon.
Here I just turned the course selector arrow to 033, and the To/From indicator is now on the same side as the course selector arrow, which means “TO”.
So in order to fly to the Tacan I need to fly course 033.So far this I understand, no problem yet.
I also understand, that when turning the course selector arrow from 213 to 033, the To/From indicator must change its state from the “FROM”-indication to the “TO”-indication. So the To/From indicator switches from the opposite side of the course selector arrow to the same side and vice versa. This change of state should happen at 90° off the current radial in both directions.
I have set course 033 and turn the course knob to the right, so the selected course increases.
At course 123 (033+90) the To/From indicator is still on the same side, as seen here.I increase course by one more degree and we see, that at course 124 the To/From indicator changes state to the opposite side, as expected.
So far this I still understand, no problem yet.
But I would have expected the same to happen in the other direction at course 303/304:
033-90 gives me 303 (=123+180).
At course 303/304 the To/From indicator should also change state from the opposite side of the course selector arrow to the same side and vice versa.When I have set course 033 and turn the course knob to the left, the To/From indicator still shows “TO” at course 000 as expected and as seen here.
But at course 359 the To/From indicator already changes state from “TO” to “FROM”, as seen here.
I would have expected this to happen at course 303 and 304.
Could this be a bug in BMS ?
I tested it on the ground before Takeoff and there it seemed OK, the change from “TO” to “FROM” and vice versa is 90 degrees from the current radial in both directions.
So it seems like a bug to me, somehow related to course “North”, while in the air.Can you confirm this, or is my thinking just confused ?
In the BMS docs Chart-Tutorial (Chart Tutorial.pdf) on page 13-14, they say, that they were having issues with the To/From indicator, but these should be fixed by now. On the other side, the Chart-Tutorial review is from 25.March 2010, so this info might be outdated.
Thanx for this sim
Sunnny -
The TO-FROM flag is (should be) strictly a relationship between the selected course and your position relative to the station. Your heading or motion is inconsequential. Pictures 2-6 show correct indications. Pictures 1 and 7 show incorrect indications. Namely a course of 359 from a position of radial 213 would be toward station so TO flag is to be displayed.
I would guess that the logic is “if bearing-to-station is ±90 from selected-course then show TO, otherwise show FROM.” And selected course 359 is not within range -57 to +123. When really the test should be within range 0-123 or 303-360.
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Well don’t bother so much with the “TO”/“FROM” indicator…
Personally I simply ignore it!
Your best/better aid is the bearing pointer of the station, means the white triangle at the outer side of the circle of the HSI.
With your first quick look at it, you know exactly where the station is, as also if you are fly “TO” it (if it is close to 12 o’clock) or if you are fly “FROM” it (if it is close to 6 o’clock).
No case to confuse yourself with this way ;).
Nikos. -
What aircraft did you fly?
I made a test in Korea with default aircraft and I don’t see the same. I see the TO/FROM flag toggling 90° off the radial, which is correct
I agree you report a problem but I can’t reproduce itIn the BMS docs Chart-Tutorial (Chart Tutorial.pdf) on page 13-14, they say, that they were having issues with the To/From indicator, but these should be fixed by now. On the other side, the Chart-Tutorial review is from 25.March 2010, so this info might be outdated.
If I remembrer right the TO/FROM was completely bugged prior to 4.32 but was fixed with 4.32, the chart tutorial was initially with FS images of the HSI to prove the issue and since then was rewritten for a BMS update in which the issue was corrected
I am in the process of rewritting the chart tutorial and I retested the (E)HSI specifically and couldn’t find anything wrong with itFurther I tested this morning the exact situation you reported and can confirm that the (E)HSI toggles indicator 90° off
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Hi Red Dog,
I’m in Israel Theater, aircraft is F-16C-40-IAF.
I just tested it again.Before takeoff, while sitting on the runway at Ramon 23R, the To/From indicator works OK.
But after takeoff, the problem shows up again. Here I’m still outbound on radial 213:I have a TE for this, but don’t know, how to attach it to this post.
Here the beginning of the debrief.txt:
–------------------------------------------------------
RECORD BEGIN TIMESTAMP 12/6/2018 20:14:08.
Game is Tactical Engagement type Local
Mission name: Ramon001
Mission Type: TRAINING
Flight Unique Id: Cowboy1
2 Ship Flight
Ac type: F-16C-40-IAF
Contry: IDF
FLIGHT EVENTS
Event Sunnny joined as Cowboy12 at 08:53:03
Event Sunnny exited from Cowboy12 at 09:04:01PILOT SLOT 2:
Human Player: 2Lt. Sunnny
Callsign: SunnnyThanx
Sunnny -
Hi Red Dog,
I ran a quick test in Korea KTO theater, airbase Sachon.
The problem is here also reproducable.
While sitting on the runway 23L the To/From indicator works OK.
But after takeoff, the problem shows up again.Here again with F-16C-40-IAF:
and here with F-16CM-40:
Is there a difference in HSI between the different F-16 variants ?
Thanx
Sunnny