Flight model realistic / ok?

I'm not sure and would like to know what you guys think, but for me it feels that the flight model of the harrier seems very "synthetic", "nervous" or something in that direction. Also while hovering it feels some kind of strange...

It is hard for me to believe that a real Harrier flies like that...

From the asymetric loadout rolling apart, this is really akward...

How do you all see that?

All other models I own feel very realistic and act as expected (maybe not 100% on the Mig29, that thing feels like a frisbee xD ).

Have there ever been a Harrier pilot saying something about the module?

The AV8B has been modelled using extensive data, the Harrier Flight model its as accurate as can be for a sim.

Also as a note we have US and British Harrier pilots input on the FM, with nothing but positive feedback :)

The AV8B has been modelled using extensive data, the Harrier Flight model its as accurate as can be for a sim.

 

Also as a note we have US and British Harrier pilots input on the FM, with nothing but positive feedback :)

What about the behaviours when flying with asymmetric loads? I specifically asked a Harrier driver about this and he said he hardly ever notices it, although it gets a bit weird during the landing. Harrier in DCS almost stalls a wing if you rifle a missile or pickle a bomb.

What about the behaviours when flying with asymmetric loads? I specifically asked a Harrier driver about this and he said he hardly ever notices it, although it gets a bit weird during the landing. Harrier in DCS almost stalls a wing if you rifle a missile or pickle a bomb.

So you have harrier SME's available to ask about how the ARBS and ASL functionality should actually work?

What about the behaviours when flying with asymmetric loads? I specifically asked a Harrier driver about this and he said he hardly ever notices it, although it gets a bit weird during the landing. Harrier in DCS almost stalls a wing if you rifle a missile or pickle a bomb.

Post a track with controls indicator and your controls setup?

I read the same article of the OP. I believe the statement was a coy reference to frequent use of the AFC. I'm not too skilled with it yet but I agree with the Harrier pilot.

So you have harrier SME's available to ask about how the ARBS and ASL functionality should actually work?

No, unfortunately, that's not the case. I asked that question 9 months ago.

Post a track with controls indicator and your controls setup?

Why would I do that? I am asking a question about flight behaviour, not really asking for help.

I read the same article of the OP. I believe the statement was a coy reference to frequent use of the AFC. I'm not too skilled with it yet but I agree with the Harrier pilot.

I don't think it's about being skilled, but rather if it's realistic or not. His comment isn't compatible with RAZBAM's flight behaviour IMHO. But then again, when you question a specific part of the FM some individuals say "you're not good enough" or something along those lines, completely ignoring the issue, which doesn't help at all...

No, unfortunately, that's not the case. I asked that question 9 months ago.

 

 

 

Why would I do that? I am asking a question about flight behaviour, not really asking for help.

 

 

 

I don't think it's about being skilled, but rather if it's realistic or not. His comment isn't compatible with RAZBAM's flight behaviour IMHO. But then again, when you question a specific part of the FM some individuals say "you're not good enough" or something along those lines, completely ignoring the issue, which doesn't help at all...

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The AV8B has been modelled using extensive data, the Harrier Flight model its as accurate as can be for a sim.

 

Also as a note we have US and British Harrier pilots input on the FM, with nothing but positive feedback :)

Or at least a "We are aware. HUD and ARBS/DMT is still WIP."

This would tremendously help to calm some people's nerves... and mine especially, for that matter. ;)

So you guys all think the Harrier flies and behaves as you would expect and you are satisfied with it?

Don't get me wrong, but flying the Harrier feels for me like flying those free figtherjets for X plane you could find in the web... Not wrong, but also not like a real plane.

When I fly the Mirage, the Hornet, the Su27, the Viggen or the FW190, it feels like sitting really in that plane and nearly feel what it will do next...

But maybe I'm all wrong about my feeling on the FM of the Harrier when you all say its fine.

Mentioning the AFC, that's very far from being realistic still. But I'm not allowed to post NATOPS excerpts anymore, so it's getting hard to get some attention here.

And as I got the feeling the Harrier now lacks thrust, I did a quick test against one of the tables found in the NATOPS, with some very interesting results that can be seen here. Too bad the track was broken, "as always"™. But very easy to reproduce... I wouldn't call this "as real as it gets" if it needs 50% more fuel in cruise speeds compared to the real one. But maybe it's just the data in the NATOPS being wrong?

When I fly the Mirage, the Hornet, the Su27, the Viggen or the FW190, it feels like sitting really in that plane and nearly feel what it will do next...

But maybe I'm all wrong about my feeling on the FM of the Harrier when you all say its fine.

With the Harrier you sit on 4 columns of hot and cold air with reaction air jets blasting out of the nose, tail and wing tips - the question is not if it flies like a Mirage or Hornet but if it flies like a Harrier.

I find the flight model believable and it hits most of the IRL performance figures.

My statement has nothing to do with my own feelings. My questions regarding the Harrier came up specifically from this Harrier pilot I spoke to.

@Shadow_1stVFW,

I haven't mentioned the word "bug" at all, not sure where you got that from. I'm not reporting a bug, I'm asking the devs about a specific behaviour of the module in flight with asymmetric loads.

What about the behaviours when flying with asymmetric loads? I specifically asked a Harrier driver about this and he said he hardly ever notices it, although it gets a bit weird during the landing. Harrier in DCS almost stalls a wing if you rifle a missile or pickle a bomb.

Why would I do that? I am asking a question about flight behaviour, not really asking for help.

 

 

I don't think it's about being skilled, but rather if it's realistic or not. His comment isn't compatible with RAZBAM's flight behaviour IMHO. But then again, when you question a specific part of the FM some individuals say "you're not good enough" or something along those lines, completely ignoring the issue, which doesn't help at all...

My statement has nothing to do with my own feelings. My questions regarding the Harrier came up specifically from this Harrier pilot I spoke to.

 

@Shadow_1stVFW,

 

I haven't mentioned the word "bug" at all, not sure where you got that from. I'm not reporting a bug, I'm asking the devs about a specific behaviour of the module in flight with asymmetric loads.

A bug, in my mind is something coded incorrectly, like the flight model you are suggesting. But we may have different definitions.

I have provided two tracks for you, or anyone else. In the first I drop a load of bombs. You can see my control deflection and land with an asymmetric load.

In the second, I land with an asymmetric load on either 1/7, I forgot.

Track 1

Track 2

I did this to show that I "hardly ever [notice]" but that is my experience. I'm not doubting yours, I'm asking what your control setup and curves are to see if maybe it's that. Because my experience seems different than yours.

And here is my roll curve setting. I use a Virpil WarBRD with no extension.

Im by far no expert in FM's nor have I flown the real thing.

What I recognized regarding asymetric load is that another well known sim of the Viper, which is credited with a near to life FM, shows far more strong reactions when dropping a bomb and creating an asymetric load.

The AV8B has been modelled using extensive data, the Harrier Flight model its as accurate as can be for a sim.

 

Also as a note we have US and British Harrier pilots input on the FM, with nothing but positive feedback :)

I dispute that. While I agree the FM in general is good, and the hover effect is really well made. - There are still issues with uneaven loads! No jet that behaves like DCS Av-8B does would be put into service as it is too dangerous. I drop one measly Mk82 and the whole airframe turns into something that is a really uncomfortable and difficult to fly. The effect is greatly overdone and should be tweaked/fixed.

But I'm not allowed to post NATOPS excerpts anymore, so it's getting hard to get some attention here.

Why would that be an issue?

1.16 Posting images, file links, and file sharing links of military aircraft documents newer than 1980 is strictly prohibited on our forums. Such posts will be removed.

https://forums.eagle.ru/rules.php#en

"Posting images, file links, and file sharing links" ; no mention of excerpts, is it ? ;)

I dispute that. While I agree the FM in general is good, and the hover effect is really well made. - There are still issues with uneaven loads! No jet that behaves like DCS Av-8B does would be put into service as it is too dangerous. I drop one measly Mk82 and the whole airframe turns into something that is a really uncomfortable and difficult to fly. The effect is greatly overdone and should be tweaked/fixed.

Try flying faster? I've launched Mavericks from one wing and dropped GBU12s from one wing, and at tactical speeds (i.e. 480kts GS or so) I do not have a jet that "turns into something that is a really uncomfortable and difficult to fly."

Try flying faster? I've launched Mavericks from one wing and dropped GBU12s from one wing, and at tactical speeds (i.e. 480kts GS or so) I do not have a jet that "turns into something that is a really uncomfortable and difficult to fly."

Ive noticed that if you fly slow the wing drop/roll effect is worse as well. If you go like 400kts+ after release the plane wants to roll, but you can trim that out pretty easy.

The assymetric wing roll has bugged me since release. Dropping a MK83 for example can make the plane roll steeply and nearly uncontrollably. And even when you trim it to level flight, pulling any G's will induce a roll again. I just can't imagine this is the case in the real thing and I've never experienced a stores-induced roll this badly even in F-16 sims when launching the heavy HARM (which does induce a roll, but it's very controllable and trimmable).

I always find this incredibly funny. There is one person on this forum that claims he has spoken to a pilot that says 'he never noticed as much'. That is very vague if you ask me, but he could be right. Then there is a bunch of people that think they know what the real thing flies like, but probably never flown themselves. Stop thinking you are an aerodynamics engineer because you fly in a simulator.

I'm not the one saying it's not right, I'm the one who asked him a question and he replied saying something else, something that is not compatible with what I see in DCS. Since his word on the topic matters, because he's a pilot and he flew the real thing, I thought it would be a good idea to let the devs know about this.

Now, if that's funny, well I can't do much about it... Just trying to show that something might be wrong. Since the PR guy said it's as good as it gets.

I know we have many expert here with years flying the real live AV8B N/A. I have never flown the real thing so there are some thing in the RL manual that I hope you guys can explain.

All of this can be found on the 2011 A1-AV8BB-NFM-000, pat IV, chapter 11

11.3.1.3 Transonic Wing Drop All variants of the AV−8B can experience a sudden uncommanded roll−off, also called wing drop, caused by the abrupt asymmetric stall of the wings. Wing drop occurs suddenly, with little or no warning to the pilot, and may occur at AOAs below the maneuvering tone. The severity of wing drop increases as Mach number increases and as altitude decreases. At Mach numbers greater than 0.8 IMN, wing drop may occur 3° AOA below the maneuvering tone. At greater than 0.8 IMN wing drop may occur 3° AOA below maneuvering tone. The severity of wing drop increases as Mach number increases and as altitude decreases. If wing drop occurs, flying qualities can be improved by reducing AOA.

 

WARNING

Transonic wing drop may occur at angles of attack below the maneuvering tone. Extreme care should be exercised at elevated AOA when maneuvering near ground level above Mach 0.8.

11.3.1.4 Force Divergence Mach Number/Drag Rise The indicated Mach number above critical Mach, which produces a sharp change in the drag coefficient (boundary layer separation due to shock wave formation ) is termed the “force divergence” Mach number. It is also eferred to as “drag divergence” and occurs on the Harrier at approximately 0.87 IMN and results in buffet, trim and stability changes, and a decrease in control surface effectiveness. If the buffet is quite severe or prolonged, structural damage or failure may occur when this boundary layer separation is experienced on the wing due to shock wave formation.

There will be a loss of lift and a subsequent loss of downwash aft of the affected area. When shock induced separation occurs symmetrically at the wing root the decrease of downwash aft of this area results in a decrease in downwash on the horizontal stabilator and thus we notice the aircraft’s tendency to “tuck”. If the wings shock unevenly due to physical shape differences or sideslip, a rolling moment will be created in the direction of the initial loss of lift and will contribute to “wing drop” and control difficulty. If either of these conditions occurs reduce the throttle and decelerate the aircraft below 0.78 IMN while avoiding any large control inputs

11.3.6 Kinematic Coupling Kinematic coupling, as it relates to AV−8B departure avoidance, is the interchange between AOA and sideslip as the aircraft rolls about its longitudinal axis. Kinematic coupling occurs when the longitudinal axis (around which the

aircraft rolls) is not aligned with the velocity vector. This can be a good thing if the aircraft has developed sideslip and then rolls into the sideslip which will turn it into AOA (which the aircraft is more tolerant of). However, if the aircraft is rolled while AOA (velocity vector not aligned with the longitudinal axis) is present, kinematic coupling will turn the AOA into sideslip which must be compensated for (either by pilot input or DEPRES) or the aircraft is susceptible to a departure. Figure 11-2 shows the mechanics of kinematic coupling.

11.4.1.2.1 AOA Lag During high AOA and/or g onset rates the HUD AOA has been seen to lag by up to 5 units. Therefore, as a pilot is maneuvering in this regime if an attempt is made to pull instantaneously to a specific AOA the True AOA of the aircraft will exceed the HUD displayed AOA. If the True AOA overshoots the lift limit the aircraft will enter stall or a departure.

1.4.1.2.2 Loaded Rolls Loaded rolls create stability problems in several ways. First, if the AOA is just beneath the lift limit, rolling the aircraft increases the camber of the up−rolling wing which may cause either laminar or shock−induced flow separation, resulting in a loss of lift and an increase in drag away from the initial roll direction. At lower IMNs this will result in wing rock; at higher IMNs it can accelerate immediately into a departure. Next, rolling the aircraft with AOA present increases the AOA on the down rolling wing, which can be thought of as “roll friction” because it is opposite the initial roll direction. Also, loaded rolls will induce the detrimental effect of kinematic coupling that turns AOA into sideslip. The result of these effects is that a loaded roll that creates sideslip and rolling moments beyond the ability of DEPRES to compensate will lead to a departure.

11.4.4.3 Angle of Attack Sensitivity As airspeed decreases, AOA increases. It is important to recognize the aircraft’s sensitivity to AOA. At slow airspeeds, small amounts of back−stick pressure and in some cases the release of small amounts of forward−stick

pressure may create a high AOA excursion. This may in turn lead to wing rock, directional instability, which the pilot will recognize as a wandering sideslip vane, and a possible departure from controlled flight. The target AOA during any slow speed flight should be 10 to 15 units AOA, although 15 to 20 units may be acceptable under certain circumstances. AOA will always increase with roll when any sideslip is present and can rapidly increase as a function

of sink rate without significant pilot aggravation. During slow speed flight when the flight controls provide reduced effectiveness, AOA management becomes critical

1.4.4.5 Stick Lightening As seen in Figures 11-3 and 11-4 there is a portion of the AV−8B maneuvering envelope above 0.75 IMN that yields a disproportionately large pitch control response for a given aft stick input relative to the rest of the envelope. The danger here is that it occurs at high transonic Mach numbers where the aircraft is already susceptible to shock induced flow separation. The larger than expected pitch response will cause excessive AOA buildup leading to flow separation (likely asymmetric) with a departure or overstress (low altitude).

1.4.5.2 Air Refueling Probe Effect With the refueling probe retracted, the effect on flying qualities at low to moderate AOA is negligible. In maneuvering flight at AOA near and above the tone, the probe causes a left wing down rolling moment that increases with increasing AOA. This rolling moment is easily opposed with aileron but the combination of probe effect and opposing aileron may cause departures at AOA above the maneuvering tone. On TAV−8B, the combination of probe effect and rudder or aileron inputs may cause departures or positive AOA autorolls at AOA above the maneuvering tone. At extreme AOA induced by VIFFing, low departure resistance and the air refueling probe effect combine to increase the likelihood of departures in the absence of aileron or rudder inputs. With the probe extended, a small amount of drag and resultant yaw is generated. If the probe fails to retract, some pilot rudder compensation will be required for landing.

Also ,for the experts, which version of the LERX do we have in DCS? 65% or the 100%

Can someone explain this to me?

This is just the clean aircraft, not talking about weapons asymmetry effects.

Edit,

Could people post tracks of the clean aircraft departures? Is hard to tell what you guys are talking about without seeing what you are doing. No weapons loaded in asymmetry yet. Thanks in advance for all the track so we can all learn.