A few more HUD inaccuracies.
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Hello, I gotta say that 4.33 is a gigantic leap towards perfecting the sim’s realism, and seeing that you all are doing that for free I’m expressing my huge thank you for that :D.
Here’s my contribution to perfect this game even more, which is purely contrived from me watching HUD tapes. I’m still a beginner and still learning the basics of aviation and BMS, so what I say will need a confirmation from the experienced ones. Also almost everything I present here I’ve seen in different tapes from different blocks and years.1. One minor difference is when rolling the F-16 in the real jet more than 45° the roll indicator’s caret doesn’t disappear, but rather partly stays at the 45° mark. This is present in every single HUD tape I’ve watched and I’ve watched a few of them. It goes like this:
2. Another one that isn’t very minor, since it can affect how hard or soft you land plus it adds to the clutter, is the FPM’s cross when it’s out of range. In-game it happens too early while in HUD tapes it happens much later (the X isn’t actually shown in the tapes but it does occur quite a distance below what’s in the sim (See post #5)). This affects how hard you land as when you flare and it gets out of range in game you don’t really know exactly where the FPM is especially if you’re coming in high or your style of flaring is sudden and abrupt as opposed to a soft and long(er) term one: This also applies to the FPM in the upper HUD, (above gun cross, when pulling negative Gs) where it gets crossed out much further up
Compared to:
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And this one’s at the bottom of the AoA staple but still hasn’t been considered out of ranged and crossed out:
While flaring:
Compared to:
Where the FPM actually gets crossed out:
The red box is roughly where a normal HUD tape would be zoomed (This is the view from LANTIRN night mode operating hud, which is “zoomed out” - see post #5)… The green FPM is just about the position where it gets crossed out in Falcon BMS.
I realise that some of my approaches are a bit high and heavier, but their AoA and FPM’s position in HUD stays the same or close to compared pictures so it makes very little difference (correct me if I’m wrong).
3. Edit: Oh and I almost forgot this one: when lowering the gears you’re also lowering the flaps, which apparently has more overall lift (at least initially) than the gears have drag (a lot more in fact, so far that in the dutch video the pilot had to pitch down about 5°’s to offset it) as evidenced by these videos:
Last one’s got loads of low approaches you can just watch him lower the gears over and over until landing.
(Clarification: In the sim, when you lower the gear your FPM goes down meaning you are losing lift (airspeed), while in real life the FPM goes up. I guess it was modeled with the assumption that the gears has more lift-spoiling drag/deceleration than the flaperons have lift, but according to HUD tapes the opposite is true. This one may be more related to flight model not the HUD.)4. Edit 2: The roll indicator at the bottom of the HUD in the simulator as compared to real life HUD tapes (of which I can’t confirm which block/country the aircraft including them is) is slightly higher in the HUD. This causes a bit of clutter when having high(er) AOA like when landing.
Comparison between one real HUD tape and a block 50 F-16CM in the sim:
Why it’s better to have its position like the real jet (at least what I understand generally from hud tapes):
If I was doing that same approach in the sim like in the pic above, the indicator would be located in or about the region of the velocity vector causing clutter.
You can add this as a feature in the new avionics editor, you can take your time if you’re going to do it, no haste at all :).5. The final difference I’ve noticed is very minor and is just cosmetic and probably has no functionality AFAIK. It’s also probably more related to flight model than the HUD or involves both, a game’s dev/programmer might need to confirm that. I’m just gonna copy paste myself from the other thread due to laziness :P. Apparently when the pilot disables nosewheel steering (like in takeoff), the gun cross which represents the nose & the FPM are “unlinked”, so to speak, in the yaw component. The vice versa occurs when landing when the pilot enables nosewheel steering where the FPM instantly gets bellow the gun cross if you understand what I mean. When the jet lands, real HUD’s gun cross and FPM behave independently when using rudders or wind hits the jet etc., it’s almost like the jet’s still in the air until noswheel steering is enganged.
It’s obvious right about 71 knots airspeed mark:Again, if any or all what I’ve mentioned here is wrong and I’ve got the whole thing misunderstood and the sim’s way is actually realistic then please ignore them, I’d appreciate as well if I’m told how I’m wrong ;).
Links to HUD tapes in order of pictures:
vgtv.no/#!/video/114647/se-hele-f-16-flyturen-fra-4-vinkler/0
vgtv.no/#!/video/114647/se-hele-f-16-flyturen-fra-4-vinkler/0 (again)
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…I applaud your powers of observation…and documentation. This is the sort of input that leads to improvement!
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Thanks, I’m trying to take the opportunity of this period of updates to the game, I’m really passionate about it and seeing it as realistic as it can possibly be :).
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I know these aren’t urgent, just need a comment from dev if you’ll have these on to do list or not. As far as I know most of them should be pretty easy to tweak.
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I just discovered where exactly in the HUD in real life does the FPM gets crossed out, there is this amazing feature where the HUD symbology get “zoomed out” in the tapes when the HUD is in LANTIRN mode in a night mission:
The quality is low, so is the fps of the video, but it’s obvious where the limits of the FPM actually are. This is from desert storm 1990/1991, a real combat operations video… The block is most probably block 40 since it was the LANTIRN capable block in the 4th TFS at that time (it’s the block which Keith Rosenkranz flew, these videos are of his flights, you can even hear him say his tail number in the vids ;)), but it’s my opinion that these are HUD standards present in all blocks. Someone more knowledgeable than me did actually confirm that.
Link:
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What about the altitude of locked airborn targets in the HUD?
Check this video at 09:28:
I don’t know which version of the F-16 this is.
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What about the altitude of locked airborn targets in the HUD?
Radar locks I can’t comment on, since they aren’t of the basic intuitive sort of difference like the roll indicator and fpm. I might need to have a look at different radar locks in different blocks too when I have the time.
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What about the altitude of locked airborn targets in the HUD?
Check this video at 09:28:
I don’t know which version of the F-16 this is.
Its an F-16CM - I would guess originally a block 42.
Id like to see the altitude under the TD box for CCIP aircraft in BMS, as well. Note that certain blocks of F-16 in 4.33 do display target altitude in the HUD, just not beneath the TD bo
Edit: Oh and I almost forgot this one: when lowering the gears you’re also lowering the flaps, which apparently has more overall lift (at least initially) than the gears have drag (a lot more in fact, so far that in the dutch video the pilot had to pitch down about 5°’s to offset it) as evidenced by these videos:
Last one’s got loads of low approaches you can just watch him lower the gears over and over until landing.
Its not real clear what you want changed about the flaperons? In BMS, lowering the gear DOES lower the flaperons.
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Its not real clear what you want changed about the flaperons? In BMS, lowering the gear DOES lower the flaperons.
Oh I thought I was obvious… In the sim, when you lower the gear your FPM goes down meaning you are losing lift (airspeed), I guess it was modeled with the assumption that the gears has more lift spoiling drag/deceleration than the flaperons have lift, but according to HUD tapes the opposite is true. It’s also obvious in the incentive ride video: gears down, loses lots of airspeed but still the FPM goes upwards almost stacking with the gun cross, instead of downwards like in the sim. (
)What I’m saying that should happen is that flaps should add more lift, or just simply make the FPM go up instead of down.
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gears down, loses lots of airspeed but still the FPM goes upwards almost stacking with the gun cross, instead of downwards like in the sim.
Note that after a few seconds as his airspeed keeps decreasing his FPM starts to go downwards again, it’s just higher than it would be without flaps at the same airspeed. Flaps down lift is modeled in BMS, I’m just saying it isn’t enough to be realistic or the gears drag is too high. I’m not sure which.
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Actually, nose down tendency is incorrect in BMS - it should rise a little. However, its not necessarily due to lift. On a FLCS equipped aircraft, it can be due to lift - but an increase lift can result in a nose down effect if accompanied by the right torque - such as that caused by the landing gear.
Note that the flaps and gears lift and drag are modeled from a real F-16 in a wind tunnel and are correct. What is incorrect is the transient forces on the aircraft during the gear movements. The end result should be the nose staying level or rising a little (according to the BEM anyway).
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What is incorrect is the transient forces on the aircraft during the gear movements.
Or that.
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Could it be that gear drag is on/off and the flaps increase with the angle? Or perhaps that is what you wrote?
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I just discovered where exactly in the HUD in real life does the FPM gets crossed out, there is this amazing feature where the HUD symbology get “zoomed out” in the tapes when the HUD is in LANTIRN mode in a night mission:
http://i794.photobucket.com/albums/yy226/Y2Jericho619/HUD%20FPM%20X%20Real%208_zpsppxim4aa.jpg
The quality is low, so is the fps of the video, but it’s obvious where the limits of the FPM actually are. This is from desert storm 1990/1991, a real combat operations video… The block is most probably block 40 since it was the LANTIRN capable block in the 4th TFS at that time (it’s the block which Keith Rosenkranz flew, these videos are of his flights, you can even hear him say his tail number in the vids ;)), but it’s my opinion that these are HUD standards present in all blocks. Someone more knowledgeable than me did actually confirm that.
Link:
… are you sure that the FOV of the AVTR is the same than the HUD? … because those records do not comes from a HUD, but from AVTR and there might be some difference in the display footprint.
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I can’t say I am sure… I am not an engineer of f-16 huds… but common sense would say that the very hud the pilot sees and the one projected over the video tapes come from the same source… This will need confirmation.
@Fenrir:Could it be that gear drag is on/off and the flaps increase with the angle? Or perhaps that is what you wrote?
The flaps extend to max angle afaik… if I understood you correctly
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I meant that perhaps the gear drag goes from 0 to 100 as soon as you press G and the flap lift increases as the angle increases, in bms that is? And that’s why fpm goes down?
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I can’t tell you, that’s something a bms programmer or dev knows. I don’t know what causes the behaviour exactly
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… are you sure that the FOV of the AVTR is the same than the HUD? … because those records do not comes from a HUD, but from AVTR and there might be some difference in the display footprint.
FOV is not the big thing to question though Deejay… the thing to note is this: That the HUD symbology is overlaid on top of the AVTR video, and is recorded separately. As long as the HUD symbology is aligned correctly, the symbols should be ‘crossed out’ when they leave the HUD FOV. It doesnt matter when the leave the video FOV - when they become crossed should be the point where they are in the edge of the HUD FOV.
Because the FPM is always displayed in the HUD at the corner, and ‘blanked’ using the X symbol inside the FPM, the point where it becomes ‘blanked’ on the video is the point where it should get blanked on the HUD in the sim.
I meant that perhaps the gear drag goes from 0 to 100 as soon as you press G and the flap lift increases as the angle increases, in bms that is? And that’s why fpm goes down?
The flaps extend to max angle afaik… if I understood you correctly
Below 240 KIAS, the flaperons are lowered to 20 degrees deflection. Roll inputs will cause one or the other to be raised, causing the roll. If implemented correctly, the end result should be that the lift is not changing at all, except if you lower the gear above 240 knots - in which case, the TEFs are lowered automatically, even above 240 knots. In that case, the total aerodynamic reaction should be changing as the TEFs lower and increase the camber of the wing. It is clear that the drag should be changing as the position changes. The exact behavior of that change seems like it would be fairly complex. Its not detailed in the NASA paper that the BMS F-16 aero model is based on. I dont know how its modeled at present, either. Seems like the devs could have come up with a convincing simulation of the exact effects with a virtual wind tunnel software and a detailed F-16 software model. Dont know if thats happened (I would guess not, but anythings possible).
I dont think the FPM lowers due to the gear drag being all or nothing and the TEFs effects being graduated, simply because that would cause the effect to only be present during LG extension at airspeeds higher than 240 knots.
Edit: Oh and I almost forgot this one: when lowering the gears you’re also lowering the flaps, which apparently has more overall lift (at least initially) than the gears have drag (a lot more in fact, so far that in the dutch video the pilot had to pitch down about 5°’s to offset it) as evidenced by these videos:
Last one’s got loads of low approaches you can just watch him lower the gears over and over until landing.
(Clarification: In the sim, when you lower the gear your FPM goes down meaning you are losing lift (airspeed), I guess it was modeled with the assumption that the gears has more lift spoiling drag/deceleration than the flaperons have lift, but according to HUD tapes the opposite is true. This one may be more related to flight model not the HUD.)In the dutch video, he drops the gear doing 254KIAS. His TEFs would have already been mostly extended anyway, at about 18° (slightly less) - dropping the gear would have just further extended them all the way to the 20° point. TEFs are only fully retracted at/above 370 KIAS.
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I’d say a bit lower than 240, the dutch F-16 got the FPM up behaviour still when he lowered gears at ~233 knots or so. But yeah it does seem the FPM remains neutral when gears are downed at lower speeds.