reported aircraft suddenly pitches up when crossing runway threshold

[BIGNEWY]

I will get some feedback from the team on this issue. 

thanks

[sinistar]

I had this issue happen to me twice a few nights ago while landing on the Syria (Al Minhad - runway 09) map on the Hoggit server. The first time, the issue was egregious enough that I had to abort the landing and go around, the second time it wasn't as pronounced and I was able to land on the first attempt.

 

 

[ColinM9991]

So this is a bug! I've experienced this several times over the past 4 months while flying the 16-2 Red Flag Campaign in NTTR, also in Caucasus at Kutaisi and Syria at Incirlik. At first I considered it to be ground effect but the bubbling is too consistent in that it looks like it's trying to trim to level flight.

It is definitely not wake turbulence, as suggested, since in my case I fly alone in singleplayer missions and/or campaigns where I'm the first to land - as is the case with the 16-2 Red Flag campaign.

[BIGNEWY]

Hi all, 

I am taking another look at this report, please include short track replay examples showing a nose lift while of the threshold.

thanks

[ColinM9991]

35 minutes ago, BIGNEWY said:

Hi all, 

I am taking another look at this report, please include short track replay examples showing a nose lift while of the threshold.

thanks

It looks like @Yurgonis the best person to look to on this topic. See page 2 of this thread.

I'll be flying the A-10 this weekend and will gather some tracks if it happens, although I'm afraid they'll be quite long as

1. They'll be from a session, and

2. I don't know the steps to reproduce this isuse other than identifying the signals of the plane going nose down during a flight, as Yurgon pointed out, where the plane then trims back to level flight as you're landing.

[BIGNEWY]

Im having problems reproducing when I try, I have one good track that shows it, but it would be great to get some more if anyone has some to add to the report

[Yurgon]

Yeah this is one elusive problem for sure! I only recall that one situation where it definitely happened to me, but I'll keep my eyes open and try to ask people for tracks when it happens to them.

I still think the underlying problem is the aircraft going nose-down somewhere midflight, and then for whatever reason it's right at the last stage of an approach, just before touchdown, when the initial nose-down-situation gets removed, and now with all the nose-up-trim that we'd added before to counter the nose down (without giving it too much thought, usually), we're now going to balloon and feel like the plain just doesn't want to be landed.

[BIGNEWY]

I have created a report for the team with what we have so far. 

[Solo_Turk]

this is my video same problem occurs time to time with f18 and supercarrier. especially on single player. there is controls indicator and i m not touching stick or throttle but plane pitching hard when i passed the borderline of the ship.

[NineLine]

10 minutes ago, Solo_Turk said:

this is my video same problem occurs time to time with f18 and supercarrier. especially on single player. there is controls indicator and i m not touching stick or throttle but plane pitching hard when i passed the borderline of the ship.

Do you see the same thing landing at an airfield though? 

[Solo_Turk]

1 minute ago, NineLine said:

Do you see the same thing landing at an airfield though? 

with a10, I have experienced this bug many times at airfields. with f18 I dont remember but maybe I haven't noticed.

[NineLine]

Send some tracks if you have them, thanks!

[Solo_Turk]

On 12/22/2022 at 1:39 AM, NineLine said:

Send some tracks if you have them, thanks!

a track for you but it is carrier, I've tried couple times to show the problem

pull up.trk

Edited January 7, 2023 by Solo_Turk

[Yurgon]

Happened to a buddy flying A-10C II tonight; his track can be found here:

https://www.yurgon.de/tmp/vJaBoG66_Caucasus_AH-64-Assault-v02-20230118-201916.trk (92 MB)

(I'll delete it at some point in the future; the link will remain active for at least a month).

 

 

[jaylw314]

Dang it, it happened to me also this week, but at the end of an hour flight.  Had to fight to trim nose down and struggled with the go-around.  Suddenly on downwind everything seemed fine again and landed normally.  I won't bother with the track, just so people know it's still there occasionally whatever is causing it.

[Shaman]

Just happened to me twice in a row on BLUE FLAG 80-ties Caucasus server. It really is strong pitch up moment just after crossing runway threshold while on the AoA ball with no reason. Having flown this beast for thousands of hours it surprised me a lot.

Edited September 16, 2023 by Shaman

[Vakari]

Sorry for no track, but I encountered this again a couple of weeks ago while trying to record a water glitch I was experiencing.

I was just starting a gentle flare on my crap landing when the nose pitched up violently, requiring a lot of forward stick to get it back down. This has happened to me maybe 4 times so far in the last month. Now that I see it isn't just me, I'll pay closer attention and try to get a track uploaded.

 

[Hive]

Thanks for posting the video! Wow, at first I thought you were flying backwards, because the water flows so fast 

Edited December 4, 2023 by Hive

[Vakari]

Referencing the following thread where it was mentioned previously and I uploaded a video where I happened to capture the effect: 

 

 

Problems: Intermittently, when landing the A-10C2 it will pitch up heavily just after crossing the runway threshold. After today's patch (2.9.2.49629) when performing my tests, my aircraft would pitch down heavily a few thousand feet before the runway threshold, then pitch up again after crossing the threshold. I had encountered the pitch up behavior maybe a dozen times prior to sitting down today to test it, and I only experienced the pitch down behavior after updating today. Maybe it's just a coincidence and the patch is unrelated.

I created a new mission to help me try and find the source of this problem. In the attached mission, 5 of my first 9 landings triggered this behavior. When triggered it applied both the pitch-down behavior followed by the pitch-up behavior. I was starting to think it had something to do with the position of the speedbrake, but my 9th attempt had these problems without using it.

Setup: Caucasus, Sochi-Adler, no wind, aircraft in-air, lined up for runway 06, 1500ft ASL, 200kts. Upon entering the aircraft I would immediately throttle to idle, lower landing gear, set full flaps, trim for approach then land. I would also tweak HUD settings and waypoint out of habit. I tend to intentionally land very early on runways.

Some details I've noticed so far:

• The pitch down behavior consistently occurs at the first line I've drawn in the attached image, roughly 3800ft before the runway starts.
• The pitch up behavior consistently occurs just after the start of the runway.
• When landing long (touch-down between the end of the tire marks and the center of the runway) I could not reproduce the issue.
• When landing steeply (5-degree glide slope) I could not reproduce the issue.
• When landing shallow (1-degree glide slope) I could reproduce the issue.

The best way I could describe the feeling is that all pitch trim is removed on approach then re-applied once over the runway. If I react quickly enough, I can pull back on the stick and hold it to maintain glide slope when the pitch-down occurs, then when the pitch-up occurs I can quickly release the stick to neutral to continue the last few feet before flaring onto the runway.

I've included multiple tracks that include this 'bug' and also tracks where I expected the bug to occur but it didn't. Let me know if there is any other information I can provide. Thank you for your time!

A-10C2 Landing Pitch No Bug 3 - Very Shallow.trk A-10C2 Landing Pitch No Bug 2 - Standard Landing.trk A-10C2 Landing Pitch No Bug 1 - Standard Landing.trk A-10C2 Landing Pitch Bug 7 - Shallow with Rapid User Response.trk A-10C2 Landing Pitch Bug 6 - Very Shallow Failed Landing.trk A-10C2 Landing Pitch Bug 5 - Standard Landing No Speedbrake.trk A-10C2 Landing Pitch Bug 4 - Standard Landing.trk A-10C2 Landing Pitch Bug 3 - Standard Landing.trk A-10C2 Landing Pitch Bug 2 - Standard Landing.trk A-10C2 Landing Pitch Bug 1 - Standard Landing.trk A-10C2 Landing Pitch No Bug 4 - Landing Long.trk A-10C2 Landing Pitch - Bug Hunt.miz

Edited December 19, 2023 by Vakari

[BIGNEWY]

Thanks Vakari, we still have a report open we will bump it and ask the team when they will have time to check it. 

thank you

[Novy]

Hey, I've started encountering this problem as well on the Operation Persian Freedom campaign. In fact, it happened so far in all the first 4 missions I've flown so far. Before this, I played through the Enemy Within III campaign and never had this happen to me. 

The issue is exactly how Yurgon described it, with pitch down after take off at around 3000ft compensated by trim, with nose going to the stars at runway threshold. All of this in the A10C-II.

Edited January 13, 2024 by Novy

[Supersheep]

On 12/4/2023 at 10:35 AM, Hive said:

at first I thought you were flying backwards, because the water flows so fast 

Off-topic: Is there a separate existing bug report open for this somewhere? 

The water wave surface "moving" with the reflections is quite obviously not right, and confused the heck outta me more than once. 

[db349]

Encountered this excessive pitch-up effect during flare as well during my playthrough of Operation Persian Freedom, as others have mentioned. Seems to be easily reproducible. I think having a low gross weight upon landing seems to be a factor.

Any news on the progress of this issue ? Seems to be a longstanding bug and many track files have already been uploaded.

Thanks.

[Ramses823]

There seems to be a strange issue what I can only describe as a heavy random drop in trim that has come up since the update and I don't think I will be able to easily come up with a track as it happened during a two hour mission on the NTTR map, so I will try my best to describe exactly what happened. I was on the NTTR map doing a series of 30 degree dive bombs runs with BDU-50s I had 4 X BDU-50 and dropped a single BDU-50 at 30 degrees on each pass.I had no issue whatsoever with the dive bomb passes but once I switched to 30 degree high angle strafe passes the issue came up randomly, so my first few passes no problem then on maby my 6th strafe pass I have the target at my 10 o'clock and as I'm on my base leg just before I roll in I give the jet three clicks of nose down trim which is my normal procedure basically one click of trim for every ten degrees of dive angle so in this case I'm doing 30 degree strafe passes so 3 clicks nose down trim; so I roll in with the sight just short of the target then I let it track up to the target and once the piper is on target I engage the pac and fire at 1.2 slant range then as I begin my 4 G climbing safe escape to 30 degrees I get my nose halfway up and then the nose just stops so I pull all the way back on the stick to continue climbing to prevent myself from hitting the ground, now this is strange behavior because normally pulling all the way back on the stick would result in a serious over G . The maximum speed for the A-10 is 450 KIAS and the fastest I got it in the dive was no more than maby 390 KIAS so I didn't overspeed the aircraft. Also after I recovered from the dive I had to add a considerable amount of nose up trim I also checked to make sure I didn't have any keybind issues I'd say the biggest clue I have at this point is there is a random drop in aircraft trim as I'm coming off target for no reason I don't know maybe it has something to do with the pac also I'm only adding 3 clicks of nose down trim just before I roll in so I'm not adding excessive nose down trim for a 30° wire at this point I've got close to 1000hrs in the A-10 so I've done countless strafe passes and have never experienced this. Unfortunately because it is completely random and when creating a fast mission it doesn't happen I'm unable to produce a track file which is very unfortunate because that makes it very difficult for the developers to narrow down the issue. Hopefully my description has been detailed enough to point in the direction of what may be going on.... as a side note the temperature was 8° C with the winds at 7 knots ground level and turbulence was set to 3...

[Yurgon]

Do you think it might be related to this pitch up issue that sometimes happens?