A32nx: [BUG] Flight Physics - Wing Dips on Flare

Created on 30 Sep 2020 · 25Comments · Source: flybywiresim/a32nx

Mod Version

v0.3.1 release version

Describe the bug

Aircraft wing dips on idling the engine when on approach

To Reproduce

Establish the aircraft in landing configuration
Idle the aircraft at 50 feet
Wing dips

Expected behavior

Wing doesn't dip (barring weather phenomena)

Actual behavior

Wing dips, linked to idling the engine

References

N/A

Additional context

Seems to be a flight model issue. Exists in the unmodded game according to MSFS Forums

Discord username (if different from GitHub):
Eefoe#0570

Bug Bug-Vanilla Plane Performance

Source

efortier-95

All 25 comments

please add a title

AdenFlorian on 30 Sep 2020

Whoops, fixed!

efortier-95 on 30 Sep 2020

Can confirm I'm facing the same issue in the unmodded game.

m-ketan on 30 Sep 2020

👍1

Definitely an issue. Doesn't matter the configuration - I can have a perfect approach and if you idle too early (even above 140kt which should be perfectly fine with landing flaps) the left wing will try to smack into the ground half of the time. This has been reported all over the place and kinda ruins every flight.

collinbrady on 1 Oct 2020

Just an update: since v0.3.1, it appears that the RIGHT wing dips now (albeit less aggressively).

I've updated the issue title and content to reflect that either wing can drop (unsure of which it is).

efortier-95 on 2 Oct 2020

It seems whichever wing is even barely out of level alignment facing down is the one that stalls. Needs more testing.

collinbrady on 2 Oct 2020

i can confirm that, when i get 150 kts aproach my wings are good, no problem landing in flare, but if i go manual my wings, falls aleatory to a side, and its imposible to land correctly... only if i hit below 145 app... its just something weird! Thank you.

Berniep94 on 2 Oct 2020

The wing dip is not tied to idling the engine. Yesterday I got it at over 100ft AGL, and I dont pull back on the throttles until 20 ft.

To add to the discussion: To me it seems like my aileron inputs are being ignored during this bug. Full oposite aileron will not correct the bug right away, it seems to ignore it. I am not getting any stall warnings, and I am well above stall speed. If this is a stall, I wouldn't know it. I've been speculating if there is a bug that under certain conditions the flare logic of the airbus of a gentle nose down of so-so many degrees per minute is translated into a banking motion instead.

August78 on 6 Oct 2020

👍1

The wing dip is not tied to idling the engine. Yesterday I got it at over 100ft AGL, and I dont pull back on the throttles until 20 ft.

To add to the discussion: To me it seems like my aileron inputs are being ignored during this bug. Full oposite aileron will not correct the bug right away, it seems to ignore it. I am not getting any stall warnings, and I am well above stall speed. If this is a stall, I wouldn't know it. I've been speculating if there is a bug that under certain conditions the flare logic of the airbus of a gentle nose down of so-so many degrees per minute is translated into a banking motion instead.

Exactly, it makes hand fly landing so so difficult as you will need to keep correcting and this roll effect basically ruins your landing

dickbig2 on 24 Oct 2020

This should not have been closed.

Benjozork on 24 Oct 2020

Has anyone observed the aileron status in the display when this happens? To see if the FBW is commanding left/right roll incorrectly.

henrikx on 25 Oct 2020

Working on it right now, will report back.

efortier-95 on 25 Oct 2020

Dev mode:
built: 2020-10-24T05:27:00+00:00
ref: refs/heads/master
sha: 16c20e42d50526cfcd042e8da51f1e08c7323008
actor: Benjozork
event_name: push

Could not recreate, ailerons remained neutral and no spoilers deployed

Conditions:

World Config: Winds calm, Temp 17C, QNH 1019, Airport at Sea Level
Aircraft config: Flaps full, Weight 68,000 kg, Vapp ~138KIAS, Autothrottle in Managed Mode through full approach, idled at 50 feet

This may be related to the change in flight dynamics, I don't think the AoA is as ridiculously high nowadays as it used to be so maybe stall protection doesn't activate?

efortier-95 on 25 Oct 2020

Tried again, still couldn't recreate.

I captured the landing with the F/CTL ECAM page on. I couldn't see any deviations other than what I commanded with the flight controls.
https://youtu.be/5KpknS44uFs

efortier-95 on 25 Oct 2020

@efortier-95 It is very random when it happens, so if you keep trying it will happen eventually.

henrikx on 26 Oct 2020

I've been doing a ton of flights the past few nights and I haven't seen it once. Will continue, but in the meantime, a couple questions for you all:

Are you landing overweight?
Are you in Config 3 (should be ~5 knots faster) or Full?

I've been able to land around 140 to 145 at Full without handling issues.

Regardless, the ground effect is still a total PITA when it comes to floating forever if you miss your flare being perfect - I assume Asobo needs to do something about that.

collinbrady on 26 Oct 2020

I've been doing a ton of flights the past few nights and I haven't seen it once. Will continue, but in the meantime, a couple questions for you all:

Are you landing overweight?

Are you in Config 3 (should be ~5 knots faster) or Full?

I've been able to land around 140 to 145 at Full without handling issues.

Regardless, the ground effect is still a total PITA when it comes to floating forever if you miss your flare being perfect - I assume Asobo needs to do something about that.

This is a known issue from asobo, not for FBW Team, it's supposed to be fixed in tomorrow upadate, we have to cross fingers hahahaha, but definetly is more stable with the new flight model & engine performance... lets see what we can expect for tomorrow update!

Berniep94 on 26 Oct 2020

I just did the Sidney landing challenge in the a320 with the FBW mod installed. As I came into the flare, the roll input become very insensitive, the plane starts to bank to the left, and the pitch becomes very sensitive. Almost like it's the opposite problem from the bank.

August78 on 8 Nov 2020

Still not getting fixed in this patch.
Disappointing...

dickbig2 on 9 Nov 2020

See the Asobo patch 6 notes say its fixed.

The Airbus A320neo Fly-by-wire bank oscillation now works properly

Its not, still happens randomly like before :/

MuppetOwl on 12 Nov 2020

Saw this post on Reddit. Thought it might help sort this out. Sorry if this is not helpful... thought it was best to ask. Thank you!
https://www.reddit.com/r/MicrosoftFlightSim/comments/juosac/simple_fix_for_a320_wing_dip_bug_plane_rolls_left/

Toneking77 on 15 Nov 2020

Saw this post on Reddit. Thought it might help sort this out. Sorry if this is not helpful... thought it was best to ask. Thank you!
https://www.reddit.com/r/MicrosoftFlightSim/comments/juosac/simple_fix_for_a320_wing_dip_bug_plane_rolls_left/

Has anyone confirmed this works - its functions are obviously related to the control surfaces, and possibly whatever is affecting them or the flight model at the end of landing? Here's that switch's operations from the A320 manual: