Difficult landing training - Page 4 - ED Forums
 


Notices

Reply
 
Thread Tools Display Modes
Old 08-09-2018, 05:09 PM   #31
Sideslip
Member
 
Join Date: Oct 2017
Location: Where it's f-ing cold
Posts: 207
Default

If you guys really feel the need to test it, go find the longest runway on a hot day, load up to max gross, take-off, land at the proper speed (10degrees AoA) and apply the brakes as soon as you put the nose wheel down, then increase throttle to maintain that speed under braking for the entire length of the runway. If you go off the end of the runway before you blow a tire, you will never blow a tire due to braking.
__________________
System specs: i7 3820 @4.75Ghz, Asus P9X79LE, EVGA GTX1080SC @2100mhz, 16GB Gskil DDR3 @ 2000mhz, 512GB 960EVO m.2, 2 X 512GB 860EVO SATA3 in RAID0, EVGA Supernova 850W G2, Phantek Entho Luxe White. CPU and GPU custom water-cooled with 420mm rad and lots of Noctua fans.
ASUS PG348Q. VKB Gladiator Pro w/MCG, X-55 throttle and MFG Crosswind.
Sideslip is offline   Reply With Quote
Old 08-09-2018, 05:23 PM   #32
zhukov032186
Senior Member
 
Join Date: Nov 2016
Location: Fort Worth, Tx
Posts: 1,058
Default

Quote:
Originally Posted by Sideslip View Post
Guys... really? Come on. Take your car down a road a 500kph and see what happens.

No, really? I never guessed, especially since I wasn't braking. That was the whole point, was to determine if speed affected them. It does, as expected.


Quote:
that has nothing to do with weight or braking or temperature
It has nothing to do with braking. It does have to do with weight and temperature, specifically the weight on and temp of the tires. It's called physics. Enjoy. We're also not talking about physically locking the brakes and skidding. We're referring to applying maximum braking and not letting off. Regardless, we've safely established brake temp is not modeled, and tires may or may not, at least on the 25T.


And lastly, Ironhand already did a full braking test under a loaded aircraft. So... thanks.
__________________
Whatever you need to be a cold, virtual killing machine Uncle Sam has you covered, and so do I! I'm Troy McClure, would I steer you wrong?

Last edited by zhukov032186; 08-09-2018 at 05:28 PM.
zhukov032186 is offline   Reply With Quote
Old 08-09-2018, 06:37 PM   #33
Sideslip
Member
 
Join Date: Oct 2017
Location: Where it's f-ing cold
Posts: 207
Default

Quote:
Originally Posted by zhukov032186 View Post
No, really? I never guessed, especially since I wasn't braking. That was the whole point, was to determine if speed affected them. It does, as expected.


It has nothing to do with braking. It does have to do with weight and temperature, specifically the weight on and temp of the tires. It's called physics. Enjoy. We're also not talking about physically locking the brakes and skidding. We're referring to applying maximum braking and not letting off. Regardless, we've safely established brake temp is not modeled, and tires may or may not, at least on the 25T.


And lastly, Ironhand already did a full braking test under a loaded aircraft. So... thanks.



My god you're hostile! But seeing the same rude attitude with your replies to draconus's other thread I'm not surprised. That or you just enjoy sarcasm a little too much. I know you don't want to hear it, but I'm actually going to type some of my thoughts and opinions into this here box.



I know you weren't braking in your test. But that's what 90% of the thread is about. Otherwise I wouldn't have gone on to talk about braking...



While you say you aren't talking about locking the brakes and skidding... that is far more likely to cause a tire failure than overheating. The whole point of the thread was what is causing tire failure on his landings (and then could braking too hard do it). If you cannot come close to locking the wheels (which in the 25 you absolutely can't), you probably cannot create enough heat to blow the tires anyway. When you see an airbus blow a tire with the brakes flaming, it's because it has (and was using at the time) an anti-skid system so it can apply maximum braking force without locking the wheels. That tremendous amount of energy is what overheats the tires, not gently braking (again, what the 25 does). If it didn't have an anti-skid, it would possibly lock one or multiple wheels, which would still cause tire failure, but those brakes would not be overheated.


So the 25 can't lock up, that's one way it's brakes can't cause tire failure. It also can't brake very hard, so it's unlikely they can overheat the tires. That's the only two ways brakes can cause a tire failure ruled out. So brakes on the 25 can't blow a tire, therefore the only other two things are hard landing or skidding.


Pulsing the brakes, brought up in this thread, is completely unnecessary.



And while Ironhand did test landing at max gross, he did not do a complete braking test to determine if brake temperature is modeled. All he did is verify that the brakes are capable of stopping a fully loaded aircraft without failure, not that they cannot fail. That's why I suggested what I did, as it's the maximum amount of brake energy that you could create on the 25 within the limitations of the sim without causing failure by rolling at ridiculous speeds. Again, I doubt they modeled that anwyay.


I wasn't twisting your arm to do the test, nor was I suggesting that you and you alone have the responsibility of proving it. I have no desire to do it because I never blow tires so it really doesn't matter to me. But if someone else really wants to find out if it's possible, that's how.


Quote:
Originally Posted by zhukov032186 View Post
If you lock the gear up it will lurch to one side, which also increases weight on that side, which increases heat, which increases likelihood of blowout. It also makes it hard to control.

While my comments are rarely addressed to one sole person (I don't provide 15 quotes for each and every topic I discuss), you yourself did specifically say not to brake too hard on the 25 or you will lock the brakes. You can't lock the brakes. It does not lurch to one side, there are no differential brakes on the 25 in DCS and there is no other way for that to happen with regards to braking force in a straight line (you certainly can with steering though). You cannot overheat the tires through braking (to the extent that Ironhand tested). While these are concerns that may exist in the real world, and I don't fault you for expressing them, they don't exist here.
__________________
System specs: i7 3820 @4.75Ghz, Asus P9X79LE, EVGA GTX1080SC @2100mhz, 16GB Gskil DDR3 @ 2000mhz, 512GB 960EVO m.2, 2 X 512GB 860EVO SATA3 in RAID0, EVGA Supernova 850W G2, Phantek Entho Luxe White. CPU and GPU custom water-cooled with 420mm rad and lots of Noctua fans.
ASUS PG348Q. VKB Gladiator Pro w/MCG, X-55 throttle and MFG Crosswind.
Sideslip is offline   Reply With Quote
Old 08-09-2018, 07:29 PM   #34
Ironhand
Veteran
 
Ironhand's Avatar
 
Join Date: Aug 2004
Location: New Hampshire, USA
Posts: 3,578
Default

Sideslip,

What I did do after the landing, however, was to make two max weight takeoffs in my trusty Su-27–one with brakes engaged for the duration in full AB and one without. In both cases, the tires blew at roughly the same speed and sequence. Front first @ around 375 and the rest at around 380 (at least I think those were the numbers).
__________________
http://rsoro.host22.com/Flankertraining_Images/Flankertraining_Banner-1a.jpg

Win 10 Pro x64, ASUS Z97 Pro MoBo, Intel i7-4790K, EVGA GTX 970 4GB, HyperX Savage 16GB, Samsung 850 EVO 250 GB SSD, 2x Seagate Hybrid Drive 2TB Raid 0.

Last edited by Ironhand; 08-09-2018 at 07:32 PM.
Ironhand is offline   Reply With Quote
Old 08-09-2018, 08:34 PM   #35
Sideslip
Member
 
Join Date: Oct 2017
Location: Where it's f-ing cold
Posts: 207
Default

Quote:
Originally Posted by Ironhand View Post
Sideslip,

What I did do after the landing, however, was to make two max weight takeoffs in my trusty Su-27–one with brakes engaged for the duration in full AB and one without. In both cases, the tires blew at roughly the same speed and sequence. Front first @ around 375 and the rest at around 380 (at least I think those were the numbers).

Yes but was that accelerating or at a constant speed? Ie, did they blow because they hit a predetermined speed of failure in the sim or because heat from the braking action caused them to fail? If you maintain a constant speed and they fail after a time, you can figure they failed from a build of up heat (or wear). If they just fail at a set speed, it might have nothing to do with the brakes being applied and could just be weight/maxgross X OAT/stdTemp X tirespeedrating = speed at which tires fail.


If you did the same but stopped accelerating at 350 and they still failed, just a little later, that would be pretty good evidence that heat caused it. Of course that's tires and not brakes. I still doubt the brakes are modeled.
__________________
System specs: i7 3820 @4.75Ghz, Asus P9X79LE, EVGA GTX1080SC @2100mhz, 16GB Gskil DDR3 @ 2000mhz, 512GB 960EVO m.2, 2 X 512GB 860EVO SATA3 in RAID0, EVGA Supernova 850W G2, Phantek Entho Luxe White. CPU and GPU custom water-cooled with 420mm rad and lots of Noctua fans.
ASUS PG348Q. VKB Gladiator Pro w/MCG, X-55 throttle and MFG Crosswind.
Sideslip is offline   Reply With Quote
Old 08-09-2018, 08:44 PM   #36
Ironhand
Veteran
 
Ironhand's Avatar
 
Join Date: Aug 2004
Location: New Hampshire, USA
Posts: 3,578
Default

Accelerating all the way down the runway. In both cases, they failed at roughly the same speed—one with and one without brakes applied. I took it as an indication that it had nothing to do with the brakes.

EDIT: Given that tire failure occurs sooner on a hot runway than on a cold one, I imagine that tire failure is based on heat buildup in the tires rather than tied to a particular speed for a given aircraft weight, etc.
__________________
http://rsoro.host22.com/Flankertraining_Images/Flankertraining_Banner-1a.jpg

Win 10 Pro x64, ASUS Z97 Pro MoBo, Intel i7-4790K, EVGA GTX 970 4GB, HyperX Savage 16GB, Samsung 850 EVO 250 GB SSD, 2x Seagate Hybrid Drive 2TB Raid 0.

Last edited by Ironhand; 08-09-2018 at 08:52 PM.
Ironhand is offline   Reply With Quote
Old 08-10-2018, 12:00 AM   #37
Sideslip
Member
 
Join Date: Oct 2017
Location: Where it's f-ing cold
Posts: 207
Default

Either heat build-up, or a simple calculation of a predetermined speed taking OAT into account. It'd be cool if it's really heat, but I'm still not sure. If you are accelerating it's hard to tell which it is.
__________________
System specs: i7 3820 @4.75Ghz, Asus P9X79LE, EVGA GTX1080SC @2100mhz, 16GB Gskil DDR3 @ 2000mhz, 512GB 960EVO m.2, 2 X 512GB 860EVO SATA3 in RAID0, EVGA Supernova 850W G2, Phantek Entho Luxe White. CPU and GPU custom water-cooled with 420mm rad and lots of Noctua fans.
ASUS PG348Q. VKB Gladiator Pro w/MCG, X-55 throttle and MFG Crosswind.
Sideslip is offline   Reply With Quote
Old 08-10-2018, 12:16 AM   #38
Ironhand
Veteran
 
Ironhand's Avatar
 
Join Date: Aug 2004
Location: New Hampshire, USA
Posts: 3,578
Default

Quote:
Originally Posted by Sideslip View Post
Either heat build-up, or a simple calculation of a predetermined speed taking OAT into account. It'd be cool if it's really heat, but I'm still not sure. If you are accelerating it's hard to tell which it is.
True. If I have time tomorrow, I’ll do a better controlled test.

I hadn’t really thought about it much before. Now I’m curious.
__________________
http://rsoro.host22.com/Flankertraining_Images/Flankertraining_Banner-1a.jpg

Win 10 Pro x64, ASUS Z97 Pro MoBo, Intel i7-4790K, EVGA GTX 970 4GB, HyperX Savage 16GB, Samsung 850 EVO 250 GB SSD, 2x Seagate Hybrid Drive 2TB Raid 0.
Ironhand is offline   Reply With Quote
Old 08-10-2018, 08:52 AM   #39
draconus
Member
 
draconus's Avatar
 
Join Date: Nov 2017
Location: Poland
Posts: 280
Default

Quote:
Originally Posted by Ironhand View Post
You can't select the T-bird in the ME to create a mission for yourself? Have you considered a repair?
Naah, rookie mistake. Starting time was set to a few minutes later so I was invited to look at the map instead of fly.

Tl;dr is you can brake however you want but don't you dare touching rudder during touchdown and be extra gentle on the runway with it until slowed down. I did my own tests with braking 100% heavy aircraft and have yet to do "Sideslip test" because it's fun :) No braking induced failures too. It's hard also because the damn thing is never going straight and you almost run into PIO too.

Btw: no hard feelings for zhukov032186. I like him the way he is ;) No need to be oversensitive.
draconus is offline   Reply With Quote
Old 08-10-2018, 12:57 PM   #40
zhukov032186
Senior Member
 
Join Date: Nov 2016
Location: Fort Worth, Tx
Posts: 1,058
Default

I was wrong, it happens ) Not very often mind you
Anyway, it's pretty clear brakes aren't a factor in overheating. I stand by everything else I said though.

Just to find out if tire failure is scripted at certain speeds. Will test later.

@sideslip
You threw chum in the water, what can I say
__________________
Whatever you need to be a cold, virtual killing machine Uncle Sam has you covered, and so do I! I'm Troy McClure, would I steer you wrong?
zhukov032186 is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

All times are GMT. The time now is 03:54 PM. vBulletin Skin by ForumMonkeys. Powered by vBulletin®.
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.