Pitch unstable in DCS 1.5.3 Update 3?

[FishBike]

Just wondering if anyone else has noticed that pitch attitude is not stable in the Mirage as of DCS 1.5.3 Update 3? The big problem where it would constantly pitch up, especially at lower speeds, seems to be fixed. But what I am seeing now is after getting it to fly level, it will slowly pitch up or down.

 

I can use pitch trim to get it stable again for a little while, but it doesn't stay that way, and I didn't think we were supposed to need to trim the Mirage much anyway. It doesn't feel like the normal change in pitch trim with airspeed that we get in non-FBW aircraft either (e.g. it'll keep pitching up as speed decreases).

 

It also seems like it takes a lot longer before vertical speed stabilizes after a small pitch attitude change, like 3-4 seconds. This was particularly noticeable during air-to-air refuelling.

 

I know there have been a lot of improvements to the flight model lately, so maybe these effects are intended. Just wondering if anyone else has noticed them, and whether they are supposed to be happening?

[FishBike]

Sure thing, I will do some more testing and see if I can give you some useful details about then this does and does not happen.

[Rlaxoxo]

It just feels it's more responsive can use some tuning towards the center tho

[Flagrum]

Just wondering if anyone else has noticed that pitch attitude is not stable in the Mirage as of DCS 1.5.3 Update 3? The big problem where it would constantly pitch up, especially at lower speeds, seems to be fixed. But what I am seeing now is after getting it to fly level, it will slowly pitch up or down.

 

I can use pitch trim to get it stable again for a little while, but it doesn't stay that way, and I didn't think we were supposed to need to trim the Mirage much anyway. It doesn't feel like the normal change in pitch trim with airspeed that we get in non-FBW aircraft either (e.g. it'll keep pitching up as speed decreases).

 

It also seems like it takes a lot longer before vertical speed stabilizes after a small pitch attitude change, like 3-4 seconds. This was particularly noticeable during air-to-air refuelling.

 

I know there have been a lot of improvements to the flight model lately, so maybe these effects are intended. Just wondering if anyone else has noticed them, and whether they are supposed to be happening?

I only took a brief ride when the patch was released, but I think, I can confirm this.

 

I had a hard time to keep her flying level, the TVV was constantly moving up or down (mostly up). Also it felt as some sort of lag when maneuvering and the TVV kept moving until it settled a bit and (almost) became stable ... but never where I wanted it to be.

 

Also very noticable: when performing a turn, keeping the TVV at the horizont line while the aircraft was banked and then rolling back to horizontal, wings level attitude, the TVV was pitching up "like crazy".

M2KC pitch up.trk

Edited April 3, 2016 by Flagrum

[Davee]

Just wondering if anyone else has noticed that pitch attitude is not stable in the Mirage as of DCS 1.5.3 Update 3? The big problem where it would constantly pitch up, especially at lower speeds, seems to be fixed. But what I am seeing now is after getting it to fly level, it will slowly pitch up or down.

 

I can use pitch trim to get it stable again for a little while, but it doesn't stay that way, and I didn't think we were supposed to need to trim the Mirage much anyway. It doesn't feel like the normal change in pitch trim with airspeed that we get in non-FBW aircraft either (e.g. it'll keep pitching up as speed decreases).

 

It also seems like it takes a lot longer before vertical speed stabilizes after a small pitch attitude change, like 3-4 seconds. This was particularly noticeable during air-to-air refuelling.

 

I know there have been a lot of improvements to the flight model lately, so maybe these effects are intended. Just wondering if anyone else has noticed them, and whether they are supposed to be happening?

 

 

+1

 

I also find pitch unstable during landing phase. Between pitch and throttle sensitivity, it seems much harder to keep the flight path maker between the brackets and needs constant adjustment. Surely it should hold speed and pitch once established and no changes are initiated by the pilot either by throttle or JS?

[FishBike]

I did some slightly more formal testing this morning. The good news it is seems really easy to reproduce this behavior:

 

DCS Version: 1.5.3.51870

 

Controls: checked that only one controller was bound to the pitch axis. Set a large deadzone (10) to ensure there was no pitch control input when the stick is centered.

 

1. Create a new mission file. Leave weather set at defaults (20 deg. C, QNH 760, wind 0 m/s).

 

2. Place M-2000C at Batumi, with waypoint type "takeoff from runway". Loadout: "empty", 100% internal fuel, 112 chaff, 16 flare, 100% gun (all defaults). Total weight=24,046 lbs. (Yesterday I was flying with a single external fuel tank and saw the same thing, though).

 

3. Save mission file and then run it from the "mission" menu.

 

4. Take off in full afterburner, raise gear, establish climb attitude, and then release the stick.

 

5. After a few seconds, the plane begins to slowly pitch up. (Ignore the TVV/FPM, look at the pitch ladder bars on the HUD). Leaving the throttle in full afterburner, the pitch up continues as the plane accelerates through 500 knots, and does not stop as it loses speed in the climb. I got to 53,000 feet and 160 knots and it was still happening.

 

6. Turn around and return to Batumi, descending at idle thrust and 350-400 knots. Same slow pitch-up continues. It seems to happen a bit faster in gentle turns (15-30 degrees bank angle) but pitches down in steeper turns (as expected).

 

7. Fly around Batumi at 5,000 feet maintaining 350 knots exactly. Same slow pitch-up behaviour continues.

 

All of this was with the mode switch set to A/A, but I had it set to A/G yesterday and saw the same thing.

[TomCatMucDe]

during take off, the plane just suddenly and violently pitches up even with me trying to push the stick forward. it is very strange.

[Davee]

Yep, that was one of the pitch issues I've been tackling this weekend, feels a lot better now, the odd pitch up behavior was not intended.

 

I've got it now in development so the response and required control is much like this video:

snip . . . . . .

 

In the video, I noticed that the front wheels touched down almost immediately at landing. No long nose up extension on touchdown. Can't tell what his landing parameters are, but I found this interesting.

Edited April 4, 2016 by Catseye

[rrohde]

As a side note, I noticed that when rolling after landing, with the nose pitched up at 14 deg AOA, the nose will keep pitching up until the plane will tail-strike. I do remember that previously the nose will settle by itself as the plane slows down - but not anymore in this new patch.

[Fab]

In the video, I noticed that the front wheels touched down almost immediately at landing. No long nose up extension on touchdown. Can't tell what his landing parameters are, but I found this interesting.

 

Well he applaied the shute as soon as he landed, perhaps its a short field he landed on

[Aeons]

The few things I noticed flying the latest Openbeta Patch 3 over the weekend:

 

1. Takeoff - You can rotate nicely but the main wheels just stick on the runway then lift off pretty violently with a severe pitch up.
   
2. Autopilot hunts - autopilot induced oscillations
   
3. Close Combat Mode - Doesn't work as designed
   

 

Few other issues but I think they are already posted elsewhere.

[Azrayen]

Agreed with your list , Aeons :)

[Voodooflies]

The few things I noticed flying the latest Openbeta Patch 3 over the weekend:

 

1. Takeoff - You can rotate nicely but the main wheels just stick on the runway then lift off pretty violently with a severe pitch up.
   
2. Autopilot hunts - autopilot induced oscillations
   
3. Close Combat Mode - Doesn't work as designed
   

 

Few other issues but I think they are already posted elsewhere.

 

 

4. Yaw trim - Isn't functionnal yet.

5. Smoke pods - Not visible on PCA, despite the fact they work, shows up "MAG" on HUD and emit Magic II seeker sound.

6. RDI (AZ/EL) - Needs a fix against frequent contact loss without any reason.

[Davee]

Well he applaied the shute as soon as he landed, perhaps its a short field he landed on

 

Good point - I didn't notice that.

[TomCatMucDe]

4. Yaw trim - Isn't functionnal yet.

5. Smoke pods - Not visible on PCA, despite the fact they work, shows up "MAG" on HUD and emit Magic II seeker sound.

6. RDI (AZ/EL) - Needs a fix against frequent contact loss without any reason.

 

7. targets appear on rada at quite close range without being able to lock at them

8. in CCM IFF doesnt work (even before the last update)

[Azrayen]

Guys, this was mostly a topic about flight model (pitch) issues.

Let's not turn it into a complete bug list, shall we?

[Rlaxoxo]

Guys, this was mostly a topic about flight model (pitch) issues.

Let's not turn it into a complete bug list, shall we?

 

That would actually be pretty good after every Patch

 

Would put all the bugs in one place and would help devs a bit

[Hadwell]

yeah, with the way the pitch works right now, it makes it extremely difficult to refuel, the autopilot doesn't maintain altitude, and when you try to hold it level manually, it oscillates, because you slow down, and it pitches more, so you compensate, then you speed up to match the tanker, and you have to compensate again... causing oscillations...

 

and then that deadzone (even if you have no deadzone set in the control options for your stick) in the center where the pitch authority(roll too) is either massively delayed, or just so subtle its hardly noticeable, you can't just see what your inputs are doing, but need to know what will happen long before you make the input, or you might overcompensate... probably the cause of those oscillations i mentioned earlier...

Edited April 4, 2016 by Hadwell

[MoGas]

Stopped flying the Mirage until it is fixed, unflyable with my axes and curves setting before the Patch has broken it.... :mad:

[FishBike]

I just re-tested with today's update. Pitch control in general is much better now, the flightpath stays pretty much where you put it once you release the controls rather than taking 3-4 seconds to settle down like it did in the previous update.

 

However the slow pitch up problem seems to be there still, especially in a gentle turn. :(

[Esac_mirmidon]

It´s me or now is a lot more difficult to air refuel because pitch responsiveness. I find now the M-2000C a lot more sensible and for me it´s almost impossible to air refuel now. My nose goes up and down no matter how little inputs i´m trying to put on the stick.

 

Before i was very proficient in air refueling and keeping my nose steady. Now i cant do it enough for air refuel.

[Angel101]

It´s me or now is a lot more difficult to air refuel because pitch responsiveness. I find now the M-2000C a lot more sensible and for me it´s almost impossible to air refuel now. My nose goes up and down no matter how little inputs i´m trying to put on the stick.

 

Before i was very proficient in air refueling and keeping my nose steady. Now i cant do it enough for air refuel.

 

Speaking about that... When switching the Air refueling switch, the FBW doesn´t tune to do the job more easily like other fighters?

[Esac_mirmidon]

Now i dont feel any change switching it on.

[Azrayen]

Nor do I.

 

I know that on some aircraft (e.g. Rafale) entering the refuel mode indeed alters the way the FBW reacts, but I've never heard of such a feature on the M-2000.

[jojo]

Switch the FBW to CHARGES mode :smilewink: