investigating New Landing Gear and Tires Problems

[4eyes]

When landing, the Mosquito's tires sink into the ground.  

 

[Art-J]

There's no need for attaching your single-threaded DCS.exe. We all have exactly the same one on our PCs  . A replay track would be much more useful. Does it happen with multithreaded exe as well?

What I see on your screens looks like a partial gear collapse combined with double puncture. Way too fast touchdown with heavy loadout perhaps? In my three takeoff and landing cycles post-update so far I haven't experienced anything like it.

Normandy 2 Manston might not be the best airbase to test such things anyway, as it seems to be more rough and bumpy than its Channel version for whatever reason and we don't know if that's a bug (which makes gear failures more likely to happen here) or intended surface modelling by Ugra media. Although one could argue that's exactly THE reason new suspension should be tested here.

EDIT: I'm not bothered by main gear units, but I have noticed much more bouncy behaviour of tail wheel unit. Its suspension compresses and rebounds much more post update, even at low taxiing speeds and on asphalt/concrete surfaces. Not enogh damping maybe? In my replay track attached below one can even hear a tailwheel damage sound kicking in multiple times when I'm just lining up for takeoff, not doing anything extreme. Later, after landing, tail wheel suspension collapses completely.

Granted, it might be exacerbated by aforementioned Normandy Manston surface issue, but still, I think tailwheel damper simulation is something devs should look into.

2.9_Mossie_susp_test.trk

Edited December 20, 2023 by Art-J

[flers]

Landings are a lot more bouncy now, the tail wheel is extreme and not what I imagine to be realistic.

[Slippa]

1 hour ago, Art-J said:

I have noticed much more bouncy behaviour of tail wheel unit. Its suspension compresses and rebounds much more post update, even at low taxiing speeds and on asphalt/concrete surfaces. Not enogh damping maybe? In my replay track attached below one can even hear a tailwheel damage sound kicking in multiple times when I'm just lining up for takeoff, not doing anything extreme. Later, after landing, tail wheel suspension collapses completely.

Granted, it might be exacerbated by aforementioned Normandy Manston surface issue, but still, I think tailwheel damper simulation is something devs should look into.

 

Glad to see this pointed out, I was thinking about posting a bug report. I flew the Mossie after the update, well, sort of. Just rolling onto the runway broke the tail wheel. I’d done nothing any differently than I would normally. No sudden braking, I didn’t even hit a bump as far as I know. As soon as I started rolling I was all over the place. I blasted through and got it off the ground but it was ugly. Next flight, exactly the same, it’s as if it’s spawning with a busted tailwheel. 

I knew I shouldn’t have run the update. There’s unlikely to be a fix this side of Christmas so that’s the Mossie out of action for the festivities. I fly it probably more than anything (determined to sharpen my bombing). Not a happy bunny… oh hang on, maybe it’s just on the N2 map? I’ll have to check it out. Something’s up somewhere.

32 minutes ago, flers said:

Landings are a lot more bouncy now, the tail wheel is extreme and not what I imagine to be realistic.

It’s busted.

Edited December 20, 2023 by Slippa
Typo

[Art-J]

^ Eh, don't be a drama queen . With collapsed tailwheel it seems to roll nicer than with functional one, so there's no reason not to fly it in the latest OB.

Unless turning gets more difficult? I haven't taxied with collapsed unit all that much so can't confirm. Flying it off Normandy Detling and Channel Manston was OK for me, though. Jumpy tailwheel, but without structural failures.

Edited December 20, 2023 by Art-J

[Slippa]

Well, maybe not that much of a drama but ya know .

Try it out, with a busted tailwheel, heavy load, 10deg flap and a long roll. You may even start a fire with it.

[Yo-Yo]

2 hours ago, Art-J said:

There's no need for attaching your single-threaded DCS.exe. We all have exactly the same one on our PCs  . A replay track would be much more useful. Does it happen with multithreaded exe as well?

What I see on your screens looks like a partial gear collapse combined with double puncture. Way too fast touchdown with heavy loadout perhaps? In my three takeoff and landing cycles post-update so far I haven't experienced anything like it.

Normandy 2 Manston might not be the best airbase to test such things anyway, as it seems to be more rough and bumpy than its Channel version for whatever reason and we don't know if that's a bug (which makes gear failures more likely to happen here) or intended surface modelling by Ugra media. Although one could argue that's exactly THE reason new suspension should be tested here.

EDIT: I'm not bothered by main gear units, but I have noticed much more bouncy behaviour of tail wheel unit. Its suspension compresses and rebounds much more post update, even at low taxiing speeds and on asphalt/concrete surfaces. Not enogh damping maybe? In my replay track attached below one can even hear a tailwheel damage sound kicking in multiple times when I'm just lining up for takeoff, not doing anything extreme. Later, after landing, tail wheel suspension collapses completely.

Granted, it might be exacerbated by aforementioned Normandy Manston surface issue, but still, I think tailwheel damper simulation is something devs should look into.

2.9_Mossie_susp_test.trk 2.25 MB · 1 download

 

Mosquito does not have any oleo dampers at all. Just tires and a stack of rubber disks as a spring. The old model does not have these options.

[Art-J]

^ Understood. I was thinking more about damping coefficient in general, separately from what the source of it is, oleo component or not.

That being said, could you please take a second look (or ask the dev responsible) at how the tailwheel simualtion works in current public version? As shown above, we're getting tailwheel collapses even from simply rolling on the taxiways and runways. Mine happened at 60-few % fuel load, standard ammo, no bombs.

It might be related to surface modelling of chosen airbases (Normandy Manston is suspicious at the moment), but shouldn't happen in either case.

Edited December 20, 2023 by Art-J

[stuart666]

Yoyo is quite right, its really was an austerity suspension. I cant take it to the bank, but Id not be surprised if its a litle less refined than say, the Yak52.

Things ive noticed, turning is a lot more difficult now, probably rightly. And you dont immediately end up on your nose when you press the brakes, again, probably rightly.I think a lot depends on the runway and the map. I landed perfectly fine at about 110mph on Manston on the Channel map. A little rougher, but broadly believable to be honest.. OTOH, I did land rather harder on heathrow on the Normandy map. It may be that a lot depends on whether you are landing on concrete or plating. It certainly IS rough on the plating, but then I would be surprised if it wasnt. The only time I folded the tailwheel is when I bounced. But again, the aircraft was otherwise undamaged, and its not like I havent done that pre patch.

I think the best thing we can do is go and experiment with this on different surfaces and different maps. Thus far for Channel its ok. For Normandy, probaby need to try that on a variety of surfaces, but it seems a little rougher so far.

[Slippa]

I just took it out on the Normandy map. It isn’t a burst tyre or busted oleo, the tail’s flicking up and down jiggling about of its own accord. I took off heavy, struggling to control it. I tried again with a lighter load and crept as carefully as I could just to move it. It’s bouncing and flickering and it’s bleedin horrible. On my second run I didn’t get to the runway as it yawed itself sideways and pointed me at a load of boxes.

it’s broken for me, no dramas, it’s ruined on the ground.

[4eyes]

Flew hours yesterday. I'm no technical person. But even I know when something isn't right.  I was hoping the latest Mosquito updates would have fixed some of its real problems. Not create more. 

[BIGNEWY]

I have removed the dcs.exe from the first post. 

Please if you are seeing an issue attach short as possible track replay examples. 

thanks 

[stuart666]

Ok, so just took a few more landings on the Channel map, at Manston. One of them I bounced and slammed the tailwheel down and broke it. Ill own that one, that was a lousy landing. and my C/O would be perfectly right ot give me a rocket for it. Second one I held off about 105mph, gently pulled off the throttle and landed on two wheels and then the tailwheel.

Ill try tomorrow on Normandy. Basically its considerably more sensitive before on a good landing posture (it really seems to like 3 pointers done gently). But it doesnt look broke to me, just demanding of careful landings. Before the damn thing must have had springs made out of unobtanium. It was far too solid, and I think everyone got used to it being like that.

As far as the tailwheel, I think its always been vulnerable. It just tends to show up more now  because its so easy to bounce.

Incidentally, I found a video showing a mosquito operating from a grass airstrip. I dont think they are that far wrong tbh.

 

And as far as bouncing, the real thing does indeed seem to be a little prone to it. Imagine what that must have felt like in the cockpit....

 

[Yo-Yo]

4 hours ago, Art-J said:

^ Understood. I was thinking more about damping coefficient in general, separately from what the source of it is, oleo component or not.

That being said, could you please take a second look (or ask the dev responsible) at how the tailwheel simualtion works in current public version? As shown above, we're getting tailwheel collapses even from simply rolling on the taxiways and runways. Mine happened at 60-few % fuel load, standard ammo, no bombs.

It might be related to surface modelling of chosen airbases (Normandy Manston is suspicious at the moment), but shouldn't happen in either case.

 

We will check. Our tests show that bumps that are even more than any common sense do not hurt the wheel, probably it's some surfaces issues.

 

[Art-J]

Thanks. I'll test some other airbases on various maps as well.

[grafspee]

I got my tail wheel busted pretty much always when i pass boundary grass/concrete at Caucasians airfields. No matter the speed it always generates loud bang sound and in 90% cases tail wheel is dead.

[Art-J]

@Yo-Yo, @BIGNEWY Gentlemen, here's a short replay track of a fast taxi test I did in stock Caucasus takeoff instant mission at Kutaisi.

In this one, tail wheel bouncing causes some form of an initial strut failure at 2:23 (as reported by post-mission briefing and indicated by audible metallic bang sound which plays whenever gear damage occurs in DCS aircraft), followed by full collapse after I turn around for next taxiing run. Mind you, I was keeping control column straight all the time to avoid any potential extra downward force component imposed by the elevator.

Granted, nobody would TAXI that fast in normal circumstances, but I think a few full takeoff and landing cycles in a row, when you do roll at higher speeds for many seconds, will be enough to accumulate damage and cause strut failure eventually. As I said previously, just one takeoff and landing cycle on Normandy version of Manston was enough to do it for me yesterday,  but maybe that version is just more bumpy than ED's one.

The most problematic thing is - these symptoms seem to be intermittent to some extent. When I tried to repeat the test at exactly the same instant mission to save another track, with comparable taxiing speeds, the tail was bouncing as previously, but no strut failure happened this time.

2.9_Mossie_susp_test2.trk

Edited December 20, 2023 by Art-J

[Davee]

1 hour ago, grafspee said:

I got my tail wheel busted pretty much always when i pass boundary grass/concrete at Caucasians airfields. No matter the speed it always generates loud bang sound and in 90% cases tail wheel is dead.

Fully agree!   Same issue here.  Channel map.

Edited December 20, 2023 by Davee

[Slippa]

Did a bit of testing and messing about. First, I grabbed the track above and took a while to suss it was for the stable DCS as opposed to OB. I haven’t updated stable yet so didn’t have the same bother there.

In OB on the N2 map I spawned from 3 or 4 different airfields, went heavy and light, with and without flaps. It’s nothing to do with the tailwheel or tyres as far as I can see. Just by rolling it as slowly as possible off the ramp the back end starts flicking vertically up and down. It isn’t even simulating vibration, more as if whoever had too much at the Christmas party got the bright idea of dusting off the Mossie files and giving it a shake-up.

You can fly it ok, I haven’t got around to landing but I can imagine. I think braking is making things worse but I’ve checked the external views half expecting to see a buckled tailwheel and can’t see any trouble. Maybe it’s not sitting where it should be but even on a taxi-way it’s bouncing about like I’m off-roading.

If it ain’t broke don’t fix it. Rolling out wasn’t something that needed fixing as far as I know. 

The only track I managed to grab so far isn’t more than few seconds long. Probably something I’ve done, I’ll have another go soon. It’s horrible as it is.

[stuart666]

Ive checked the braking, its thus far much better with no nose overs. Which judging by the weight sat almost directly on the wheels and how tail heavy a mosquito was, was always somewhat unlikely. Yes, you CAN just about do it, but its a lot harder

Ok, so the tailwheel fails when you taxi too fast. Pardon me for pointing out, isnt that a case for saying dont taxi too fast? I dont taxy about 10mph, and im struggling to find problems thus far.

Just tried caucasus. Had a smooth take off, which considering how bumpy the Russian runways are in caucasus I thought was pretty good. Landing was bumpy, but suspension soaked it up pretty well. I experimented with driving onto grass from the runway. By and large I found absolutely no problem. I DID have one tailwheel collapse. But that was by throwing a very tight turn at high speed, which created almost a nose over (still very hard to do it) and when the tail slammed back down, it broke the tailwheel.

Thus far, Ill be honest, Im struggling to find problems with this. Yes, its more sensitive. But frankly, I dont want it dumbed down. I already hate that the swing on take off seems to have been dumbed down compared to what it was. This shouldnt be warthunder.

Ill try the psp plating on Normandy next and report back.

 

Edited December 21, 2023 by stuart666

[stuart666]

I was trying the start mission at Villacoubray. Its very bouncy on the taxiway. Arguably it should be more so than the concrete, but this seems excessive. It may be that at least some of the problems people are experiencing are with the Normandy map. I notice even sat on the dispersal pan, there is a slight wobbling as the aircraft is running. Maybe on startup perhaps, but running at idle seems a little excessive.

Will experiment further.

Edited December 21, 2023 by stuart666

[stuart666]

Seem to be having a nightmare of a time landing on grass strips on Normandy. Tried Guyancourt and the undercarriage folds up. It may be that im not confortable landing on grass strips, but I dont think the landings are that hard to warrant this. Can anyone replicate?

[stuart666]

Its purely subjective on my part, but after landing on numerous strips on Normandy, it looks to me as if Normandy is rather harder to land on than Channel. At least the grass and dirt strips at any rate. Im quite happy for people to contradict me on that, but thats a low and dirty opinion after making a few landings. Im getting numerous gear crack ups Im near certain i would have walked away from on a concrete runway or other maps.

[Art-J]

7 hours ago, Slippa said:

First, I grabbed the track above and took a while to suss it was for the stable DCS as opposed to OB.

Nah, both my tracks are recorded in OB after Tuesday patch.

4 hours ago, stuart666 said:

Ok, so the tailwheel fails when you taxi too fast. Pardon me for pointing out, isnt that a case for saying dont taxi too fast? I dont taxy about 10mph, and im struggling to find problems thus far.

The point I emphasized in my post is, after taxiing, you WILL roll fast at 3-point for a dozens of seconds during every takeoff and landing. So whether you want it or not, the tailwheel assembly will be cumulating damage. My fast taxiing was just simulating beginning of a takeoff roll, or standard roll-out after landing. The strut may or may not fail in a mission where you perform only one takeoff and landing in a row (depending on which map and airbase we're trying), but with more of these it will fail eventually and I'd hazard a guess Mossie maintenance technicians didn't have to fix or replace tailwheel units every 3 missions or so in real life  .

I specifically avoided rolling over grass-concrete boundary, as this one has been known for causing failures in previous DCS versions already, I also avoided grass strips in my tests, 'cause concrete / asphalt ones should in theory be smoother (?). Last but not least I avoided Marianas map, which also has some rough surface mesh issues at Anderson. Just chose stock mission at Kutaisi for this very reason, not getting beyond the runway.

The only grass strip takeoff and landing at Normandy I did once was at Detling and they went OK, but that's obviously not enough reference data. Your observations from other grassy airfield there are interesting, will try them when I have time.

Edited December 21, 2023 by Art-J

[Yo-Yo]

No, wheels do not cumulate damages.