For RagnarDa, PLAN sight behavior

I think a slight tweak is necessary for the PLAN bombing sight. It is very intuitive and useful except in one phase.

When ANF is engaged, the sight, when pointed at a point on the ground, will guide you to the safety altitude set in the mission planner assuming a correct QFE setting. This works perfectly. Let's call this phase 1.

If you wait until the vertical fin appears to trigger unsafe, often times the sight will "jump", as more accurate slant range is acquired. If the sight moves low off the point designated, a climb is commanded, and vice versa a dive would be required.

However, this sight does not move like the sight in phase 1. Instead of responding to your pitch to guide you to the safety altitude, it seems to respond to your altitude, meaning the pipper won't be over the target point until you've climbed to the safety altitude. This doesn't seem accurate. Let's call this phase 2.

Phase 3 would be holding the trigger. When you do this, you're given a steering order. The steering order behaves like the phase 1 sight, in that if you pitch up, the pipper will be in the order such that by the time you get to the target, you will be at the safety altitude. This is why most youtube videos you see the trigger is depressed late (on flash of the range bar or when the sight falls below the nose, as the instructions indicate). However, they should have already adjusted their pitch attitude, so it becomes impossible to "chase" the steering order as there is no pitch that would achieve the safety altitude at that point.

I believe that the "phase 2" sight should behave as the "phase 1" sight. This seems very intuitive and would cause the instructions to be perfect. As of right now, if I see the sight jump, I immediately hold the trigger and use the steering order to get me on target. If the phase 2 sight (after trigger unsafe) behaved like the phase 1 sight (before trigger unsafe), when the sight "jumped", you would adjust pitch to bring the pipper on target the same way. If maintained, when the trigger is held in, the pipper would be right in the middle of the steering order.

I hope this makes sense.

TL:DR, after trigger unsafe in PLAN mode, I believe the pipper's vertical positioning should respond to pitch, indicating the correct pitch to arrive at the safety altitude when the target is reached, just like the pipper before trigger unsafe. Right now, it appears after trigger unsafe to respond to altitude, not pitch.

For RagnarDa, PLAN sight behavior

I think you are right. The original documentation is extremely vague on how this mode works. I think it would be ideal if the sight didn’t jump after trigger unsafe but instead started moving downwards to match your closing to the target, and as you said if pointed at target you will overfly the target at the safety height instead of right now. I’d have to think about how to solve this mathematically.

Edit: one thing I realize after thinking about it for 5 mins is that it really can’t work like you describe in phase 1, since that sight is fixed in relation to the airplanes waterline IIRC. If so that also needs to be changed so that it is fixed relative to the airplanes alpha.

Edit 2: Another thing, if the sight should not jump while using radar ranging I'd have to implement some type of transitioning because the sights position would have to be updated when marking the target if using radar ranging.

I think you are right. The original documentation is extremely vague on how this mode works. I think it would be ideal if the sight didn’t jump after trigger unsafe but instead started moving downwards to match your closing to the target, and as you said if pointed at target you will overfly the target at the safety height instead of right now. I’d have to think about how to solve this mathematically.

 

Edit: one thing I realize after thinking about it for 5 mins is that it really can’t work like you describe in phase 1, since that sight is fixed in relation to the airplanes waterline IIRC. If so that also needs to be changed so that it is fixed relative to the airplanes alpha.

 

Edit 2: Another thing, if the sight should not jump while using radar ranging I'd have to implement some type of transitioning because the sights position would have to be updated when marking the target if using radar ranging.

I think the sight actually should jump. The issue is the behavior after. Phase 2 should behave just like phase 1 and 3. The jump is to be expected as triangulation is used until trigger unsafe so the solution must be updated for the new slant range.

It would probably works similarly to the steering order in phase 3, wherein when proper pitch (not altitude) is achieved, the pipper is on target and moves down the sight glass along with the target.

I think you got it near perfect save for this one minor tweak. Phase 1 and 3 are intuitive and it makes this one of my favorite profiles to fly.

EDIT: it just dawned on me the slowness to respond might be the target coming closer at the same time the adjustments are made. You might already have this working right and i'm just rushing the flight corrections. Let me test this more this evening and I'll report back

Just did a several runs. The "phase 2" pipper is definitely strange. It forces you to guess the correct attitude to maintain throughout the pass. The "phase 3" steering order is excellent and bang on and does provide the necessary corrections. I can attach a track of a very simple mission I ran where I do a simple pop-up at about 10km out from the target, set the sight on the target, unsafe when radar ranging is available. The sight jumps low, so I engage a climb to compensate. The sight isn't quite on target yet (still low), but when I hold the trigger I'm commanded to drop the nose slightly. I follow the steering order and the bombs come off at exactly 400m and are a direct hit on the target, an ammunition depot. Safety altitude here was the default 400m.

Again, not a huge deal, the sight is probably my favorite bomb sight in any jet, I find it intuitive and accurate, but the phase 2 sight should probably be on target when the proper nose attitude is reached, as the phase 3 steering order does.

Hey Ragnar, I think I figured out what's going on here after a LOT of testing.

It seems the phase 1 sight does not guide to the safety altitude like it should. I've ensured a good QFE setting, and did several (about 50) passes. For a medium safety height, the sight seems to guide the aircraft to around 290-310m instead of 400m. It's consistently too low. I did several passes, switched the hud to LD (baro altitude), manually flew to 400m. At this altitude, the sight should be keeping me at level flight. However, it's still guiding me to descent at this altitude.

I've also tried approaches from below the altitude, starting from an altitude of 50m and initiating a pop-up at 10km out from the target. Same result, sight guides me in to about 300m, so when i trigger unsafe, a sharp climb is commanded to make up the extra 100m.

QFE checked several times. Also, the target ring is dead center of the target. I also tried passes with NAV bombing (Weapon selector in RR and master mode NAV) to check my QFE against another mode. Bombs land squarely on target in that mode, and the pole track always guides to 400m.

Once in phase 2, the sight dot appears over the designated area at around 350m and stays there until about 420m, which seems accurate.

The drops themselves land on target (though maybe a little long, hard to say).

Also, to answer Edit 1, that may be the reason it's guiding low, I'm not sure, is that it commands a climb but is ignorant to the actual vector of the aircraft. That would lead to it guiding low consistently like it does, so I think you might be on to something there.

Thoughts?

I posted this in the bug thread, but will post it here for other people to see who are scratching there head at the PLAN bombing sight. The sight before trigger unsafe should guide you to the safety altitude (default 400m unless changed in the mission editor). Instead, it guides the aircraft to a lower altitude. In the screenshots below, I have the HUD set to show barometric altitude. The sight should command a climb (I was at 50m) until I reach 400m. Instead it has me level off at 300m (see the ADI). When I go trigger unsafe, this causes the sight to "jump" below the target, indicating I should climb to get the pipper on target.

The other parts of the sight appear to function properly.

Hopefully this is a quick fix for HB, looks like a small overSIGHT (ba-dum-tiss) on their part.

I'll see myself out..... :pilotfly:

EDIT: Turns out I can't attach the same file in two different places, so here's the link to the post:

https://forums.eagle.ru/showthread.php?t=243466

Ok NOW I'm leaving :pilotfly:

I'm probably being really really stupid but while the HUD is showing you are at the correct altitude in the screenshots isn't the Flight Directory needle on the ADI showing you are below the commanded altitude (horizontal indicator above the horizon line) ?

It is. It's the sight that"s bugged. Can't use the ADI to designate the target.

I’ve spent this week looking into this and made some changes. The mode is still a fair bit confusing and as said the documentation is very vague but I will try to explain the difference between my interpretation and yours. In the other thread you assume that the safety height will be achieved in “phase 1” over the selected waypoint (ie B1). I don’t think this is correct, the wording in the documentation is very different to the “NAV-fällning” where the waypoint position is used as a target. In “phase 1” the documentation only mentions the sight is set “as a function of safety height and the airplanes altitude”. It doesn’t unfortunately mention what the third variable would be in that function but until now I just assumed it would be a fixed distance (4km) and a arbitrary angle (3,8deg) taken from elsewhere in the documentation. When originally creating this mode I tried out a bunch of different interpretations of the wording and arrived at the “current” solution as the one that made most sense.

In the internal build are now a bunch of changes to the sight that includes adding the climb angle into the mix so that the plane more easily will reach correct height. Still unsure this is correct according to the docs but it works well. Also corrected the radar measurement so now it’s a lot more accurate and QFE don’t matter as much. Found a bug too that would make the bombs miss. Hope you like it!

Damn, give me the code, NOW! :D

Just kidding, thanks for digin' into the deep!

I knew this when reading the books: the most things to be repaired (or simply to be made better) are a combination of extensive research, interpretion and highest programming skills.

Luckily its HB who is taking care of this little beast!

I’ve spent this week looking into this and made some changes. The mode is still a fair bit confusing and as said the documentation is very vague but I will try to explain the difference between my interpretation and yours. In the other thread you assume that the safety height will be achieved in “phase 1” over the selected waypoint (ie B1). I don’t think this is correct, the wording in the documentation is very different to the “NAV-fällning” where the waypoint position is used as a target. In “phase 1” the documentation only mentions the sight is set “as a function of safety height and the airplanes altitude”. It doesn’t unfortunately mention what the third variable would be in that function but until now I just assumed it would be a fixed distance (4km) and a arbitrary angle (3,8deg) taken from elsewhere in the documentation. When originally creating this mode I tried out a bunch of different interpretations of the wording and arrived at the “current” solution as the one that made most sense.

 

In the internal build are now a bunch of changes to the sight that includes adding the climb angle into the mix so that the plane more easily will reach correct height. Still unsure this is correct according to the docs but it works well. Also corrected the radar measurement so now it’s a lot more accurate and QFE don’t matter as much. Found a bug too that would make the bombs miss. Hope you like it!

Sounds great! I think my main gripe with it's current implementation is that if you're not holding the trigger it's really difficult to gauge your attitude (climb angle). If you wait too long to hold the trigger it's impossible to use the steering order.

The way I currently use it is I designate the target as soon as I have radar ranging available then immediately hold the trigger to get the steering order (I don't wait for it to slide under the nose or the ranging bar to flash). This works well and makes bombing much smoother but it's not how the manual indicates it should be done. Have you changed the 3rd phase? I hope not, that works perfect.

Can't wait to see the new implementation! Is it slated for the next OB update?

Tangentially related, but I've noticed that with the Trigger SAFE, the pipper is not at a fixed depression.. it is dependent on speed.

I engaged Altitude Hold over the sea at my Safety Height and configured ANF-BOMB PLAN. With the Trigger SAFE the pipper is below the horizon on the water. If I reduced IAS the pipper rose to the horizon (depicting a location farther away).. when I accelerated the pipper descended.

Maybe there's a time factor in the location of the pipper?

I’ve spent this week looking into this and made some changes. The mode is still a fair bit confusing and as said the documentation is very vague but I will try to explain the difference between my interpretation and yours. In the other thread you assume that the safety height will be achieved in “phase 1” over the selected waypoint (ie B1). I don’t think this is correct, the wording in the documentation is very different to the “NAV-fällning” where the waypoint position is used as a target. In “phase 1” the documentation only mentions the sight is set “as a function of safety height and the airplanes altitude”. It doesn’t unfortunately mention what the third variable would be in that function but until now I just assumed it would be a fixed distance (4km) and a arbitrary angle (3,8deg) taken from elsewhere in the documentation. When originally creating this mode I tried out a bunch of different interpretations of the wording and arrived at the “current” solution as the one that made most sense.

 

In the internal build are now a bunch of changes to the sight that includes adding the climb angle into the mix so that the plane more easily will reach correct height. Still unsure this is correct according to the docs but it works well. Also corrected the radar measurement so now it’s a lot more accurate and QFE don’t matter as much. Found a bug too that would make the bombs miss. Hope you like it!

Thinking about this a bit more, shouldn't the angle be at least 5deg to facilitate radar ranging before designation?