[REPORTED]Tires still blowing out in 1.5 (possible old bug?)

[OnlyforDCS]

Like the title says, the SU-27 Tires still feel very much bugged in 1.5. Im getting blowouts on landing and applying full brakes, in fact it is almost impossible to stop the plane without blowing out the tires without aero-braking and use of break chute to slow the plane down below 100kph before applying full breaks.

 

I haven't included any track files but it is very easy to reproduce, just land the plane and try to apply full breaks.

 

Are the Su27 tires really this fragile?

Edited October 29, 2015 by BIGNEWY

[BIGNEWY]

Hi, please provide a track showing the issue, we will take a look, thanks

 

edit

 

we do have a current report internally

[OnlyforDCS]

Hi, please provide a track showing the issue, we will take a look, thanks

 

edit

 

we do have a current report internally

 

Hi Bignewy. I have a dentist appointment today after work, then have to pick up the wife from the airport, restring my guitar for a gig tomorrow, and then a gig after work tomorrow but will make the effort to record a track by Saturday at the latest.

[BIGNEWY]

It is ok we have a report open so it is not necessary now, enjoy your day and gig, and drive safely :)

[OnlyforDCS]

Cheers, and thanks! :thumbup:

[winchesterdelta1]

I actually did not had any tire blow outs in 1.5 and i noticed i can actually hold full brakes longer than in 1.2.6. No issue at all to come to a halt even on small runway's.

 

** My landing speed is around 250.

[GGTharos]

Im getting blowouts on landing and applying full brakes, in fact it is almost impossible to stop the plane without blowing out the tires without aero-braking and use of break chute to slow the plane down below 100kph before applying full breaks.

 

Sounds like correct behavior. What's the speed when you apply full breaks?

 

Are the Su27 tires really this fragile?

 

If it helps, 'touch and go's' in certain air forces don't 'touch' at all, because it wears out the tyres.

[OnlyforDCS]

Sounds like correct behavior. What's the speed when you apply full breaks?

 

Im not sure, but it was over 100kph and less than 200kph definitely. Like I said, I wasn't sure that it's a bug, but it does seem very strange that I can break in the Mig21 (and all the other aircraft) at significantly higher speeds without fear of a tire blowout. With that said I tested this a couple of times, with a pretty full tank of fuel (around 80%) and full weapon stores. Maybe it's related to that. I will test some more today if I can find the time, or on Saturday at the latest. Do full wheel brakes in the SU27 induce wheel lock? Because that could very well be the reason they keep blowing. If that is the case perhaps the brakes can be bound to an axis? Is that even a possibility in the FC3 modeling with the Su27?

 

If it helps, 'touch and go's' in certain air forces don't 'touch' at all, because it wears out the tyres.

 

Wearing out the tire is not the same as blowing out a tire.

[GGTharos]

If a touch and go is a problem, imagine full power braking.

 

But yeah, sounds maybe a little suspicious ... but not much. Just don't lock the brakes until you're under 100 and you're golden.

 

For the F-15 IIRC manuals show that braking under 60kts everything is ok, above that you can have hot brakes, and depending on the speed you started braking at, the tyres will either blow later or they'll blow if you take off again (they go into the wells where they cannot dissipate heat). In view of that it isn't entirely unfair to just simulate the tyres as being blown.

 

But maybe, just maybe they're all little too sensitive in-game.

[rrohde]

Maybe ED could add a wheel brake axis instead of only having the on/off type button we have now. Such axis would allow us to dose the braking power we provide while braking.

[ekg]

Maybe ED could add a wheel brake axis instead of only having the on/off type button we have now. Such axis would allow us to dose the braking power we provide while braking.

 

Does the Su-27 have this? I would like to be able to use the toe brakes on my rudder pedals :D

[pr1malr8ge]

Does the Su-27 have this? I would like to be able to use the toe brakes on my rudder pedals :D

 

No, still not wheel brake axis able to be assigned to rudder pedals.

[DarkFire]

I usually land at around 270 - 290 Km/h or for a very heavy bird as high as 300 - 310 Km/h. I only ever apply the wheel brakes when my speed is below 100 Km/h or for a heavy bird below 80 Km/h. Happily the airbrake together with the drogue chutes provides some excellent braking.

 

The only time I end up popping tyres is when I land a heavy bird at too high vertical velocity or if I end up accidentally taxiing too fast. The tyres aren't nearly as delicate as they were when the Su-27 first got the PFM, but maybe they could do with a slight health buff?

[DrDetroit]

If needed (landing too hot) I simply bump the brake button several times, in short quick bursts, and never fully engage it until I'm under 80kts. Haven't ahd any mishaps since doing it this way, and not coming in so fast.

 

Good day,

 

DrDetroit

[Nedum]

I think the problem is how the brakes are working for the DCS Su27!

It seems so that they are working instant all the time.

We press the button and the brakes grab as hard as they can.

That is not how it should work.

We need a time in which the power of the brakes come in and grab more with each second we hold the brake button.

I beleive this is the way the RL system is working for the Su27. If not.. stupid engineering I guess! ;)

[OnlyforDCS]

The hardest point of impact on the tires is on touchdown. They don't blowup then, they blow up whenever the wheelbrake button is pushed and held above 100km/h. The brakes should not be inducing wheel lock at those speeds but they seem to be, as there is no other physical way that the tires could simply explode while going in a straight line (no vertical speed on the runway), to me that either indicates a problem, or more likely the brakes are very powerful and fast acting, which means that it's user error exacerbated by the fact that we have no visual or auditory indication of their work.

 

What I notice missing from the (CTRL+ENTER) overlay is the brake force indicator. At least Im not seeing it. But maybe if it was included we could more easily dose the brakes in a sort of manual 'ABS' mode to prevent wheel lock and tire burstage. Is this feasible? People are asking for an axis, but Im not sure that the brakes in the real Su27 have an axis, as they seem to be very similar to the Mig21 brakes and are activated with the lever on the stick, so a brake 'power' indicator like in the Mig21 or L39 for example would probably be ideal.

Edited October 30, 2015 by OnlyforDCS

[OnlyforDCS]

Tested some more today, and found that it is possible to break above 100 kph, without blowing out the tires, and without the use of a drag schute, by a successive rapid 'break and release' method. Still feel that a break indicator (in the RCTL + ENTER window) would be a very beneficial adition.

[Nedum]

The Su27 has an automated brake system, which makes it possible that the Su27 only need 1650 ft with a normal landing weight to stop and this without a parachute.

Never was there a notice that a Pilot must use the brakes like in an old car without ABS and that seems to be the problem for the DCS Su27. There is no automatism built in and so we need to use a manual Pilot "ABS" to not blow away the wheels.

The parachute is for short traks and bad weather conditions!

We should hold the whole long time the brake button after the touch down and the wheels should never blown away!

 

http://aviationweek.com/site-files/a...0of%202%29.pdf

Edited October 31, 2015 by Nedum

[OnlyforDCS]

Well with all due respect, that's a newspaper (or rather magazine) report. Im not sure that all the information presented there is of the most accurate sort. The pilot himself stated that he did not fully depress the brakes, whatever that means, since the brake is centered on the flight column or stick. I would like to see some official confirmation whether the brakes in the SU27 are "automatic" and what that actually means.

[Nedum]

Well.. this special part gave me a raised eyebrow too. ;)

 

But on the other hand an ABS for fighter Jets isn't a new thing and to brake only by pressing a knob isn't new too.

I can't believe that a Russian fighter jet, built to land in (more or less) urban terrain on short tracks, should have a brake that the pilot must manage with only one knob to not blow away the tires.

The tires can withstand a 22+ tons landing, but not a hard brake... hmm.. no!

The tires must be manual manage to get an ABS effect..... another no!

Even in old days there was a way to "automate" a brake in such a way, that the brake would not get to hot.

First use the right material and second use a speed/pressure driven brake system.

For all known logic... if older planes are using such an automated system and you can hold down the brake button the whole long time until the plane stops, why should the Russians not use such a system for a fighter jet?

We all should keep in mind that we are not talking about emergency landings!

We are talking about normal landings at which tires blow away for no known reason if the pilot use the brake in such a way they would be used in every plane now and before.

Sometimes I have the feeling the Su27 was built to kill Pilots as fast as possible (S-Key and brake system). Very strange if you ask me!

;)

[OnlyforDCS]

At the very least I would like to see a brake axis, if indeed the brakes can be controlled in that way as your report seems to suggest. Bignewy has stated that they have an internal report of the issue so I guess all we have to do is wait and see what ED implements.

[Hummingbird]

Su-27 doesn't have an ABS system? Really??

[CoBlue]

Latest v1.5.2

I'm getting tire blowouts just on taxing, anyone else experiencing the same?

[rami80]

Latest v1.5.2

I'm getting tire blowouts just on taxing, anyone else experiencing the same?

Yep, nothing has changed. You still have to apply the breaks for a second over and over. Holding it will most certainly cause a blowout even below 40kmph

[Nedum]

Su-27 doesn't have an ABS system? Really??

 

Right from the beginning the Su27 has a very good ABS (anti brake-lock system) for planes.

Read this article:

http://aviationweek.com/blog/pilot-reports-mikoyan-mig-29-and-sukhoi-su-27-1990

 

At the end there are two links to a pdf file. The second one shows at the end that the Su27 has an advanced automatic brake system which makes it possible to brake within 1650 ft without the use of the parachute and tire blow-ups. And there are some points which show that the DCS FBW system isn't working like the real one. The real one has a force pressure system to override the "save" flight zone. So you must switch the buttons to get in the "Cobra modus" and even then you must use extra force to override the save zone. You will only get more AoA if you get over this special pressure zone. With this system there is no need to fear a not neutral trimmed plane, because there is no change until the pilot forces the plane with extra pressure at the end of the stick zone to do so. Even so explained the us pilot that the plane is very well controllable at a high AoA at 97 knots.

 

I can only tell that more people should read this article. Could be an eye opener for some!

 

The problem is that it is not build in for the DCS Su27. What we have in DCS is more a TBS (tire blow-up system).

Edited January 31, 2016 by Nedum