Wheels blows up

[ebabil]

during the taxi, wheels blows up easily. is that normal?

and i cannot set the correct taxi speed. plane does nothing until some point, and if i come to this point, plane accelerate too fast, if i apply brake in this point wheels blow up as i mentioned or plane rolls out of the way.

[Tower95]

Hi ebabil,

 

when you are trying to taxi, you have to keep in mind a few things:

 

1. It is not a car you are handling here, do it behaves different:

-> when starting to taxi , apply just a bit of aviable thrust and wait until the airplane starts to move slowly(this will take 2-3sec.), it will then speed up without additional thrust.

 

2. steer carefully: When you have nose wheel steering enabled (green light under the scratchpad) you have to steer the aircraft very careful by slowly applying rudder, otherwise there is the possibility of the aircraft tipping over to one side ore tires deflating- also try not to leave the paved surfaces because the A10 is not built for "soft" surfaces

Edited December 6, 2014 by Tower95

[Witchking]

I remember the engine effects were not yet fully modelled. But YoYo was mentioning that this is normal. This is the concept of static friction...but makes me wonder why no other aircraft shows this issue.

I found you have to start moving..then slowly cut the throttle/brake as necessary to stay within 30km/h. If you go faster than 50 or so and try turning, it can rip ur tires. Although...Its pretty tough to rip tires even when landing at 250 km/h and swerving left and right with the rudder. haha

[Witchking]

also try not to leave the paved surfaces because the A10 is not built for "soft" surfaces

 

You mean Su-27? :p

[ebabil]

Hi ebabil,

 

when you are trying to taxi, you have to keep in mind a few things:

 

1. It is not a car you are handling here, do it behaves different:

-> when starting to taxi , apply just a bit of aviable thrust and wait until the airplane starts to move slowly(this will take 2-3sec.), it will then speed up without additional thrust.

 

2. steer carefully: When you have nose wheel steering enabled (green light under the scratchpad) you have to steer the aircraft very careful by slowly applying rudder, otherwise there is the possibility of the aircraft tipping over to one side ore tires deflating- also try not to leave the paved surfaces because the A10 is not built for "soft" surfaces

 

thanks for the tips. i will try them but i saw no wheel stering enable/ disable light or option. where is it?

 

 

I remember the engine effects were not yet fully modelled. But YoYo was mentioning that this is normal. This is the concept of static friction...but makes me wonder why no other aircraft shows this issue.

I found you have to start moving..then slowly cut the throttle/brake as necessary to stay within 30km/h. If you go faster than 50 or so and try turning, it can rip ur tires. Although...Its pretty tough to rip tires even when landing at 250 km/h and swerving left and right with the rudder. haha

 

completely agrre with you

[Robin_Hood]

It has nothing to do with static friction IMO. It is the way thrust is modeled in relation to the engine nozzles (realistic or not, I cannot say). The same things happen in flight, just try it (from idle to 79% you just hopelessly lose speed, then at 80% thrust kicks in, and stays down to 74%, below that you'll fall out of the sky again).

 

See here

[Ironhand]

I remember the engine effects were not yet fully modelled. But YoYo was mentioning that this is normal. This is the concept of static friction...but makes me wonder why no other aircraft shows this issue.

I found you have to start moving..then slowly cut the throttle/brake as necessary to stay within 30km/h. If you go faster than 50 or so and try turning, it can rip ur tires. Although...Its pretty tough to rip tires even when landing at 250 km/h and swerving left and right with the rudder. haha

FWIW, I've happened across some in cockpit videos of Su-27s taxiing and you can hear the engines spooling up and down as the pilot constantly worked the throttle. Wish I could find them again. Not sure about the "static friction" part. It has to do with how the engines are tuned. It's definitely not for taxiing. I find, however, that since the last update, taxiing is a lot easier.

 

Interesting to note that the real-world manual states that taxi speeds should not exceed 50 km/hr (straight line, no nearby obstructions) and turns should be made at speeds no greater than 20 km/hr. And the turns should have a radius of 5 meters or more.

 

 

Rich

[Witchking]

Good to know. Thanks for the info Rich & Robin. I did notice something like that while in the sky too..especially for landing... sometimes trying to throttle up to increase the speed just doesn't work as immediately as you want it to...its like there is some lag time.

[joey45]

. sometimes trying to throttle up to increase the speed just doesn't work as immediately as you want it to...its like there is some lag time.

That be the engineis spoling up.

[Witchking]

That be the engineis spoling up.

 

I meant in the air.

[Haukka81]

I meant in the air.

 

Its same thing in air, you won't get more speed right after you hit throtle, there is lag just like in real life :thumbup:

[Ironhand]

Its same thing in air, you won't get more speed right after you hit throtle, there is lag just like in real life :thumbup:

To expand on his statement just a bit, Witchking, below about 77% RPM, the engine nozzles are fully open and are producing minimum thrust. So it takes awhile for speed to increase. About 77-80% RPM, the nozzles partially close in order to improve on thrust. It's just the way the engine is tuned. Your power band in this aircraft is in the range above 80% RPM and that's where you'll see a quicker response to throttle movement.

 

 

Rich

[Ramstein]

yes! I noticed the tires blow way too easily, if you use the brakes much.. and if you try a corner at more than a crawl they blow... very weak tires now...

[Witchking]

To expand on his statement just a bit, Witchking, below about 77% RPM, the engine nozzles are fully open and are producing minimum thrust. So it takes awhile for speed to increase. About 77-80% RPM, the nozzles partially close in order to improve on thrust. It's just the way the engine is tuned. Your power band in this aircraft is in the range above 80% RPM and that's where you'll see a quicker response to throttle movement.

 

 

Rich

 

Makes sense. Thanks. Nice to see you around here again Rich. :) Keep us posted if you ever decide to stream on twitch etc. I just tried it today. Pretty cool. :pilotfly:

[ebabil]

itried to wait for a while engines to spool up but nothing happened.

this problem belongs to su-27, no other planes. i tried a-10, su-25t but all of them are ok, they make taxi easily but su-27..

 

i apply some power but nothing happens, then i add more power , nothing happens and finally i add much power so that plane moves like a catapult stone. i have to push brake and my wheels blow up.

 

i can not leave the runway properly, plane stops in the middle of the runway till i set the speed.

[Shadow KT]

Ironhand, should I post my track here ;d

[Ironhand]

Ironhand, should I post my track here ;d

Which? Sure. I hope to be able to get some cockpit time myself tomorrow. Some time is opening up for me to "play".

 

itried to wait for a while engines to spool up but nothing happened.

this problem belongs to su-27, no other planes. i tried a-10, su-25t but all of them are ok, they make taxi easily but su-27..

 

i apply some power but nothing happens, then i add more power , nothing happens and finally i add much power so that plane moves like a catapult stone. i have to push brake and my wheels blow up.

 

i can not leave the runway properly, plane stops in the middle of the runway till i set the speed.

Something is obviously not right. Does it behave the same way, if you disconnect your flight stick and use the keyboard commands to spool up? I wonder if you should do a repair of the sim. EDIT: Before doing a repair, etc. make sure to try disconnecting all devices so that only your keyboard and mouse remain (TIR, too, if you use it). It almost sounds as if something is keeping the brakes (W) engaged. Check for anything assigned to the W key.

 

 

To expand on his statement just a bit, Witchking, below about 77% RPM, the engine nozzles are fully open and are producing minimum thrust. So it takes awhile for speed to increase. About 77-80% RPM, the nozzles partially close in order to improve on thrust. It's just the way the engine is tuned. Your power band in this aircraft is in the range above 80% RPM and that's where you'll see a quicker response to throttle movement.

 

 

Rich

 

Concerning taxiing the Su-27. Since posting the above, I've seen videos where it's obvious that only one throttle is being advanced and retarded while the aircraft (real world) is taxiing. I don't have a spit throttle but that might be a way to maintain speed control with less frequent throttle manipulation.

Edited December 15, 2014 by Ironhand

[AussieGhost789]

An interesting thing to note about the nozzle squeeze is that, when you're landing the nozzles maintain a 'squeezed' position, making it much easier to make small adjustments at low RPM while on final.

 

- Cutlass

Edited December 15, 2014 by AussieGhost789

[Nedum]

itried to wait for a while engines to spool up but nothing happened.

this problem belongs to su-27, no other planes. i tried a-10, su-25t but all of them are ok, they make taxi easily but su-27..

 

i apply some power but nothing happens, then i add more power , nothing happens and finally i add much power so that plane moves like a catapult stone. i have to push brake and my wheels blow up.

 

i can not leave the runway properly, plane stops in the middle of the runway till i set the speed.

 

A well known behavior for the DCS Su27.

Some say that's right so, I doubt that.

You have to go above 78% power to get the engines above this force line that makes the plane rolling. After that you can go down to 72% and it feels the acceleration is the same as with 79% power, but know you can lift up the power from 72% to 78% and you feel there is every % a little bit more thrust.

If you go under 72% power the engines will go to idle power, even if you raise the power after you was on idle to 77%, there is no thrust input anymore till you get above 78% power again.

The same behavior in the air. If you was only one time under 72% power, you must raise the power above 78% to get the engines out of the idle position, after that you must see that you will never get the idle position or you must play this ugly game again.

There was a thread with a nice diagram showing this DCS Su27 engine behavior very clear.

There is no power till you push the engines one time above 78% power.

If I push the throtlle slowly from idle position to 78% position I can hear the engines going up, but I can wait 1 hour and longer and the Su27 stands still like a stone, nothing happened till I get over 78% power and at this moment, the Su27 beginns to speed up very fast,. even if I slow down to 73% power!

If you want to taxi the DCS Su27 you must the whole time long go from idle to 79% and vise versa.

I hardly doubt that the russian build such "strange" engine behaviors to hold the cockpit work extrem high! ;)

 

There is one video in the forum, that should show this behavior if the Su27 is standing still, but in this video was a wood break in front of a wheel, so I think this video shows nothing right. The pilot has to raise the thrust so high because of this wood break. ;-)

Edited December 15, 2014 by Nedum

[Ironhand]

An interesting thing to note about the nozzle squeeze is that, when you're landing the nozzles maintain a 'squeezed' position, making it much easier to make small adjustments at low RPM while on final.

 

- Cutlass

Happens when your wheels come down, I believe.

[Shadow KT]

Ironhand... the one where my wheels blow up.... how come u have forgotten so quickly :(

[Ironhand]

Ironhand... the one where my wheels blow up.... how come u have forgotten so quickly :(

Duh! Senior moment.