Su-27 Wheel Brake Axes

[Witchking]

How many times has this issue been brought up??....seriously...later era aircraft or later iterations/modifications have added toe brakes...but watch even the su 27 best fighter aircraft documentary on youtube... the original manufactured flankers/frogs/most russian aircraft have A BRAKE LEVER. That is what is implemented. If we get a newer version of the aircraft, ED will add it as appropriate. If you guys appreciate BMS for its realism...work with this as it is more realistic than what you are asking for. Use the pinkie paddle on the warthog for brake. It works well...try it out...you will get a better handle of how to use the aircraft and it is accurate to real life.

[ZaltysZ]

On the Stick's "pinky switch" there is a line up brake, not sure if this is for take off only.

i always thought there were no toe brakes, but it seems there is. Anyone?

 

It boosts the main brakes so that they can hold aircraft still until engines spool up before takeoff roll. For other normal braking operations only toe brakes are used.

[Weta43]

From an after flight report by a USN pilot :

 

"Having also flown the MiG-15, -21 and -29, I immediately noticed that the Su-27’s cockpit displayed a generational leap in human factors and an abidance with industry convention. Gone was the single hand-brake lever on the control stick for normal braking in favor of individual toe brakes. ... Ready to taxi, I stepped on the toe brakes for chock removal, and the pedals went right to the hard stop. Convinced we had lost hydraulic pressure, I held up the evolution until Kvochur explained that what I was feeling was normal. The brakes behaved normally during the ensuing taxi, but I didn’t care for the insufficient pedal-force increase as the brakes were applied. Perhaps this was the result of a first foray into toe brakes for the Russians, or the result of the inadequate "feel" of a brake-by-wire system, or maybe that feel is exactly what their pilots wanted."

[Sov13t]

Going to quote my own reply from a similar thread.

 

The SU-27 is equipped with both pedal actuated brakes (main braking) and stick mounted brake (start brakes) of course there is an emergency braking system as well.

 

The difference is the pedal actuated brakes provide 105-120 kg/cm2 pressure and can be used for differential braking, while the start brakes provide 175-220 kg/cm2 pressure allowing to hold the aircraft still at higher engine RPMs applied uniformly across the two main wheels.

 

The start brake engagement is not quite digital but close to it. The pilot does not have feedback/control as to how fast/intense the brakes are applied. The release is near instant. As mentioned above, the brake lever on the stick is used only when lined up for take off.

 

Edited November 26, 2014 by Sov13t

[Auger73]

How many times has this issue been brought up??....seriously...later era aircraft or later iterations/modifications have added toe brakes...but watch even the su 27 best fighter aircraft documentary on youtube... the original manufactured flankers/frogs/most russian aircraft have A BRAKE LEVER. That is what is implemented. If we get a newer version of the aircraft, ED will add it as appropriate. If you guys appreciate BMS for its realism...work with this as it is more realistic than what you are asking for. Use the pinkie paddle on the warthog for brake. It works well...try it out...you will get a better handle of how to use the aircraft and it is accurate to real life.

 

Arguing from the perspective of ergonomics of the real aircraft doesn't make sense, as the ergonomics of how 99.99% (probably higher) of DCS players are nothing like the aircraft they are simulating. Unless you have a sim pit designed with the layout of the real bird, you really aren't experiencing the ergonomics of the real bird. Don't get me wrong - if you can afford to do it, kudos to you! Most of us plebes have to make due with what we have.

 

The real question is whether the Soviet aircraft had digital or analog brakes. Like every other control in DCS, you should be able to map the input wherever you want.

 

For me, I have a Logitech G940, which has fewer control inputs than I like, and unused wheel brakes are wasted controls. On the MiG-21Bis, I map the right brake pedal as my brake lever, and I am cool with that. I would have no gripe doing that for all aircraft which only have 1 brake control.

Edited November 26, 2014 by Auger73

[Witchking]

Arguing from the perspective of ergonomics of the real aircraft doesn't make sense, as the ergonomics of how 99.99% (probably higher) of DCS players are nothing like the aircraft they are simulating. Unless you have a sim pit designed with the layout of the real bird, you really aren't experiencing the ergonomics of the real bird. Don't get me wrong - if you can afford to do it, kudos to you! Most of us plebes have to make due with what we have.

 

The real question is whether the Soviet aircraft had digital or analog brakes. Like every other control in DCS, you should be able to map the input wherever you want.

 

For me, I have a Logitech G940, which has fewer control inputs than I like, and unused wheel brakes are wasted controls. On the MiG-21Bis, I map the right brake pedal as my brake lever, and I am cool with that. I would have no gripe doing that for all aircraft which only have 1 brake control.

 

Well...one thing I agree. I know the brake is a LEVER on the early flankers as well as the frogs and toads...but I do not know whether if it is an analog brake input.. or a "all" or "none" button style input. If it is analog, I agree, perhaps it needs to be assigned as an axis. But we won't know until Dima & ED decide and let us know.

[Weta43]

"The real question is whether the Soviet aircraft had digital or analog brakes."

 

When Soviet says 'digital', what he actually means is binary - with the level on the stick they're basically either on, or they're off.

Yes - pre-production Su-27 had the same lever type braking as Su-25 etc.

Production Su-27S (what we have in DCS) have toe brakes that (while they don't have the same feel) function in the same way as western toe brakes.

They also have a secondary lever on the stick for use at takeoff, which applies the brakes very hard till released.

Edited November 26, 2014 by Weta43

[Auger73]

"The real question is whether the Soviet aircraft had digital or analog brakes."

 

When Soviet says 'digital', what he actually means is binary - with the level on the stick they're basically either on, or they're off.

Yes - pre-production Su-27 had the same lever type braking as Su-25 etc.

Production Su-27S (what we have in DCS) have toe brakes that (while they don't have the same feel) function in the same way as western toe brakes.

They also have a secondary lever on the stick for use at takeoff, which applies the brakes very hard till released.

 

Binary is digital. And by digital I meant it is either "On" or "Off" - it isn't just a Soviet thing. :)

 

Yes, you can have digital controls mimic analog controls, such as digital potentiometers, and analog controls can have their signal converted into a digital one.

 

I would argue the toe brakes on my G940 feel more like Soviet toe brakes than American toe brakes from the description. :music_whistling:

[Weta43]

Binary is digital. And by digital I meant it is either "On" or "Off" - it isn't just a Soviet thing. :)

 

:)

 

Not sure if I'm misunderstanding you here...

 

'On or off' is binary, which is a subset of digital. "Digital" control need not be binary ( having states of "off, 1/4 on, 1/2 on, 3/4 on, full on" would still be 'digital' in a control sense).

 

Yes, you can have digital controls mimic analog controls, such as digital potentiometers, and analog controls can have their signal converted into a digital one.

 

I would argue the toe brakes on my G940 feel more like Soviet toe brakes than American toe brakes from the description. :music_whistling:

 

Maybe, but the Su-27 takeoff brakes are not digitally controlled in that sense, they're 'analogue' systems, that essentially only operate in 2 states - on & off - so in that sense they're mechanical but binary ..

[Auger73]

:)

 

Not sure if I'm misunderstanding you here...

 

'On or off' is binary, which is a subset of digital. "Digital" control need not be binary ( having states of "off, 1/4 on, 1/2 on, 3/4 on, full on" would still be 'digital' in a control sense).

 

Maybe, but the Su-27 takeoff brakes are not digitally controlled in that sense, they're 'analogue' systems, that essentially only operate in 2 states - on & off - so in that sense they're mechanical but binary ..

 

Anything digital can be represented in "on or off" binary terms. You may need more than 1 binary switch. Everything your computer processes is binary and digital.

 

I am more interested in the "non-takeoff brakes" to be honest - as taxiing and landing are where I mostly use brakes. Maximum performance take-offs are fine, but I rarely do them. Having a separate "take-off" brake system would be fine, though.

[Weta43]

"Anything digital can be represented in "on or off" binary terms."

 

Strictly speaking, that's not true.

 

Yes, everything in your computer is digital and binary, but digital doesn't mean binary, just that the the values have discrete steps, not a continuous range of variables.

 

So a stream of information (or a control system) that where each instruction can have (for example - because that's how many fingers on a hand, and that's where the digit in digital comes from - fingers) 5 discrete states would be digital, but not binary.

 

Sometimes the 'binary' of computers and 'digital' get rolled into one, but that's not what 'digital' actually means.

 

Anyway - well OT..

 

The toe brakes are analogue - as many states as you want :)

[Auger73]

"Anything digital can be represented in "on or off" binary terms."

 

Strictly speaking, that's not true.

 

Yes, everything in your computer is digital and binary, but digital doesn't mean binary, just that the the values have discrete steps, not a continuous range of variables.

 

So a stream of information (or a control system) that where each instruction can have (for example - because that's how many fingers on a hand, and that's where the digit in digital comes from - fingers) 5 discrete states would be digital, but not binary.

 

Sometimes the 'binary' of computers and 'digital' get rolled into one, but that's not what 'digital' actually means.

 

Anyway - well OT..

 

The toe brakes are analogue - as many states as you want :)

 

5 discrete states would just require 3 bools to describe. It is just like how 119 is still a decimal number, even if you don't have 119 fingers. (Just think of the HOTAS setup you could use with 119 fingers, even if it made you looked a bit like something from Cthulhu fan fiction!)

[OnlyforDCS]

Holy offtopic batman! I just want to know when the brakes are going to stop blowing my tires when taxiing. ;)

[Weta43]

<OT>

 

5 discrete states would just require 3 bools to describe. It is just like how 119 is still a decimal number, even if you don't have 119 fingers. (Just think of the HOTAS setup you could use with 119 fingers, even if it made you looked a bit like something from Cthulhu fan fiction!)

 

Your're still conflating digital and binary :) They're not necessarily the same thing.

 

Digital data, in information theory and information systems, are discrete, discontinuous representations of information or works, as contrasted with continuous, or analog signals which behave in a continuous manner, or represent information using a continuous function.

 

Although digital representations are discrete, the information represented can be either discrete, such as numbers and letters or continuous, such as sounds, images, and other measurements.

 

The word digital comes from the same source as the words digit and digitus (the Latin word for finger), as fingers are often used for discrete counting. Mathematician George Stibitz of Bell Telephone Laboratories used the word digital in reference to the fast electric pulses emitted by a device designed to aim and fire anti-aircraft guns in 1942.[1] It is most commonly used in computing and electronics, especially where real-world information is converted to binary numeric form as in digital audio and digital photography.

 

So 5 states dosn't require 3 booleans, 5 possible states is digital in itself.

 

</OT> (seriously ;) )

 

Holy offtopic batman! I just want to know when the brakes are going to stop blowing my tires when taxiing. ;)

 

No science here, only observations, but I think it takes about 4 seconds of the brakes being on for them to engage fully when landing. If you hold 3, release momentarily, hold 3 etc, I don't think you'll pop the tyres...

[ShuRugal]

Your're still conflating digital and binary :) They're not necessarily the same thing.

 

They are the same thing. Anything which is represented digitally is done through the use of a series of binary digits.

 

If something has five discrete states, its digital representation would consist of three digits (or bits). the possible states would be 000, 001, 010, 011, and 100. three more states are possible with a 3-bit block (101, 110, and 111) but in this case they would be unused, as your device only has 5 possible states.

 

Digital == the use of binary bits to represent non-binary information.

 

 

but back on topic...

 

No science here, only observations, but I think it takes about 4 seconds of the brakes being on for them to engage fully when landing. If you hold 3, release momentarily, hold 3 etc, I don't think you'll pop the tyres...

 

I've found that as long as i maintain a perfectly straight course, i can hold the brakes down continuously until i am stopped and they won't blow anything.

Edited November 27, 2014 by ShuRugal

[Weta43]

They are the same thing. ...Digital == the use of binary bits to represent non-binary information.

 

No they're not, and it doesn't...

 

It's true that when talking about computers they are, and you're focusing exclusively on computers, but computers aren't the whole world :)

 

The word <edit - I had Binary, I meant to write digital> DIGITAL pre-dates computing, and has a wider meaning than the narrow meaning you're applying.

 

See above for the wider meaning.

 

No more from me on the subject.

 

As I think I mentioned earlier, the braking > tyre damage model is being worked on.

Edited November 28, 2014 by Weta43

[ShuRugal]

No they're not, and it doesn't...

 

It's true that when talking about computers they are, and you're focusing exclusively on computers, but computers aren't the whole world :)

 

Except that we are talking about computers? We are talking about a computer (Digital) representation of mechanical objects.

 

The word binary pre-dates computing, and has a wider meaning than the narrow meaning you're applying.

 

yes, binary means, loosely, "having to do with or consisting of two". A binary star system has two stars; a binary compound consists of exactly two elements; a binary chemical weapon consists of two (relatively) harmless chemicals, which combine to produce something much nastier upon release.

 

 

However, as far as 90% of the places you are likely to see the word used, 'binary' is linguistically indistinguishable from 'digital'. Prior to the 1950's, the word binary was scarcely used at all (Source). It was only with the invention of the digital computer in the 1940's that the word began to spread into society, and really only within my own lifetime has it become a common word.

 

No more from me on the subject.

 

as you say, then.

 

As I think I mentioned earlier, the braking > tyre damage model is being worked on.

 

can't wait for the patch, taxiing on eggshells sucks.

Edited November 28, 2014 by ShuRugal

[Weta43]

Actually we were - & still are - talking about electro-mechanically operated hydraulic brakes on an Su-27S, which we can all cross our fingers and hope will one day be assigned to axis ...

[ShuRugal]

Actually we were - & still are - talking about electro-mechanically operated hydraulic brakes on an Su-27S, which we can all cross our fingers and hope will one day be assigned to axis ...

 

in that case i apologize for the misunderstanding, I thought we were discussing the digital modelling of such.

 

And I will definitely join in on the finger-crossing.... please please please, give me control over my brakes! SU-27 would fail VA state vehicle inspection with the brakes in their current state....