Aircraft Rudders

[Hunin 0]

Depends on what jets exactly we are talking about.

It's easy to get the impression that rudders are not really needed in modern jet aircraft because jets don't tourge much.

Rudder trim is mostly automated nowadays.

If you count trim as rudder work then, yeah. The airplane does it by itself.

Think about it:

Assume that you fly a combat jet and you rudder is completely automated.

Nice for flying from waypoint to waypoint.

But what do you do in a knifefight?

Trying to place lead with ailerons and elevator alone?

[Hunin 0]

Here is a short clip from a documentary where you see a Comanche in flight. It looks to be about the same size as the cobra, but I am not sure how much better it performs. But if you can fly sideways at the speed in the video, shouldn't you be able to turn from side to side with the tail rotor at the same speed?

http://uk.youtube.com/watch?v=zkQJOsqV8rw

IIRC the comanche was designed that way. Should you try something like that in an Apache you'd be sure to break something.

Then what exactly ( besides the MMI ) is the difference that allows the Comanche to pull of this stuff?

[MehMan 0]

I have no clue man, that's what I know from watch shows. I think it was advanced avionics that enabled it.

[Gisen 0]

Rubbish. Helicopters can fly sideways. The only thing that STOPS them flying sideways and spinning is, in fact, the tail rotor (/ counterrotating blades on Hokum etc.)

Flying sideways does mean that airflow is now pushing against the side of the heli rather than the front, so the maximum speed obtainable without too much torque on the rotor depends on the aerodynamic qualities of the side of the heli, which is why some (such as the Hokum) are able to fly much better than others 'sideways.'

[Guest RKSL-Rock]

I have no clue man, that's what I know from watch shows. I think it was advanced avionics that enabled it.

Advanced flight controls do make it easier to fly sideways at higher speeds but it makes no difference at lower speed.  Its the simple physics of the helicopter's wind resistance at various angles to the direction of flight that cause the problem.

I've seen several Puma HC2 fly sideways at a reasonable speed, Seakings and Lynx too.  I've even seen video of Merlins and Chinooks fly at various angles from the direction of flight.  It is physically possible in the real world.  Helicopters can fly sideways, but the speed depends on thier available power and the drag generated by the surface area of the fuselage.

Regarding Fast Jets, as someone said before.  The rudder has little effect at higher speeds and is really only used to trim the aircraft.  But at lower speed (that figure depends on the rudder surface area and distance from the CofG) it does have an effect.

Right now ArmA's flight model is arse about face.  Helos fly like planes and planes like helos.  I understand why it was done like this.  It make AI use of the aircraft far easier. But it still feels wrong.  What’s needed for the helicopter class is an extra set of parameters in the config:

1 - Yaw rate - just like elevator sensitivity.

2 - Yaw cut off speed - Speed value where the rudder degrades.

Planes would also massivley benefit from this too.  I'd like to see thrust simulated properly too and not just mass divided by throttle position.

Maybe if we all stop arguing and come to a consensus BIS might actually know what it is we want.  There are so many conflicting opinions its hard to know what is actually wanted.

[frederf 0]

Quote[/b] ]Flying sideways does mean that airflow is now pushing against the side of the heli rather than the front, so the maximum speed obtainable without too much torque on the rotor depends on the aerodynamic qualities of the side of the heli, which is why some (such as the Hokum) are able to fly much better than others 'sideways.'

This is rather thinly applied logic. By the same argument you should be able to throw a bar-variety dart sideways.

[Pulverizer 1]

Quote[/b] ]Maybe if we all stop arguing and come to a consensus BIS might actually know what it is we want. There are so many conflicting opinions its hard to know what is actually wanted.

Don't you remember the mass-bitching about helo flightmodel being too difficult compared to OFP and too easy and unrealistc compared to Flight Simulator X. It's impossible to make a compromise that wasn't too far from both. There would have to be realism settings for the flight model, to please everyone.

Then again, it's not a helo/jet/tank/sniper/etc sim. Just a game with some funny shit that looks a bit like real-life military equipment.

[Guest RKSL-Rock]

This is rather thinly applied logic. By the same argument you should be able to throw a bar-variety dart sideways.

That’s not thin.  That’s totally accurate.

What you aren’t considering is how helicopters actually fly.  If you were to equip a " bar-variety dart " with an engine, main rotor and tail rotor it could fly sideways.

You're rubbishing his statement without any basis in fact.  Your dart is designed to fly in one direction only and only has the energy you give it.  Helicopters aren’t darts.  They can affect their own direction of flight.  Then as long as the tail rotor can produce enough torque to maintain the turn then it can fly at almost any angle.  When it can't produce the required power it loses rudder authority and succumbs to drag.  This means the aerodynamic forces caused by the fuselage will force the aircraft along its direction of flight.  But only long enough until the tail rotor can produce enough torque to affect the turn again.

I'd suggest you do some research and learn how helicopters actually fly.  Its quite interesting and should give you a far better appreciation of what’s being discussed.

Don't you remember the mass-bitching about helo flightmodel being too difficult compared to OFP and too easy and unrealistc compared to Flight Simulator X. It's impossible to make a compromise that wasn't too far from both. There would have to be realism settings for the flight model, to please everyone.

Then again, it's not a helo/jet/tank/sniper/etc sim. Just a game with some funny shit that looks a bit like real-life military equipment.

Wellthe result of that epic was that we got left with the current flight model. I’m not proposing that we revert to the OFP days nor revisit the nonsense of that little debate. I’m suggesting a fix for the rudder issue mentioned in this thread. What are you suggesting?

[Pulverizer 1]

Quote[/b] ]I’m suggesting a fix for the rudder issue mentioned in this thread. What are you suggesting?

Well, I dunno, leave them as it is and focus on the gfx engine performance, stupid as f... AI and the worst bugs for starters. Oh, and the linux server might be in order too. Or the modding tools.

For BIS to please the flight sim crowd would be an endless swamp so to speak so what's it matter to take a tiny little step like making the rudders alter the course of a jet in flight slightly.

[Guest RKSL-Rock]

Well, I dunno, leave them as it is and focus on the gfx engine performance, stupid as f... AI and the worst bugs for starters. Oh, and the linux server might be in order too. Or the modding tools.

For BIS to please the flight sim crowd would be an endless swamp so to speak so what's it matter to take a tiny little step like making the rudders alter the course of a jet in flight slightly.

Well if they are already at work on the GFX issues and all the other wonderful stuff you seem interested in, why not add one more thing to the wish list? I don’t think anyone is screaming for or expecting an instant fix on this issue.  Well not any of the "Flight Sim crowd" that I know of.  Do you know different or are you just reading something into this because you have your own agenda?

Personally I'm into the Sim part of this game.  I don’t care if its air or ground based. Anything that adds to the immersion and realism is a good thing, whether you are in the air or on the ground is irrelevant.

ArmA is a “Combat Simulator†not an infantry simulator.  Atleast that’s what BIS say.  What’s wrong with asking for features that enhance one aspect?  Other aspects are also being reworked and enhanced.  Why not the flight sim side?  Or are you afraid you’ll be swamped with people wanting bomb you?

[Pulverizer 1]

Believe me, I'd like ArmA to be the "ultimate combat simulator" too but it's just not gonna happen. And no, I wouldn't be afraid because I play mostly coop and there's no way the damn AI could do shit with the planes

[Col.Flanders 0]

How about this:

Forget "FSX" flight models on one hand and "After Burner" ones on the other. (But just so you know, i'm quite happy with the helo flight model EXCEPT for this rudder issue)

The helicopters in the game (as in real life) are there for various reasons but in this case, one of their most common functions is to kill ground targets. As it is, the game's helos are seriously hampered in this regard because of their inability to use gun and rockets (barring hellfire) when moving forrwards. The reason: rudder (tail rotor) has no effect when flying faster than 40/50km/h. The solution: make it effective at more than 40km/h. As it stands, the only forms of attack helo that would be effective in-game would be the Apache because of its hover behind cover to pop-up-and-fire type tactic and the Hind because of its almost fixed-wing high speed attack tactics.

If the Cobra, littlebird and UH60-FFAR were like this in real life, then the military would never use these machines as they would not be practical. As intended attack choppers with weapons dependent on rudder input for ground attack, they're not effective in the game either. Make them effective. Make them functional. We don't need to have "ground-effect" or molecular aerodynamics modelled. We just need functionality.

Sorry, my post was meant to present a simple answer...it ended up being an essay.

[-HUNTER- 1]

I dont know what this topic is about.

No really, I know there are some small bugs with the rudder, but with helicopters your not supposed to use the tailrotor at higher speeds anyway.

If you cant hit the targets and need to use the tailrotor to change direction, you've not started your run properly.

And need to take more distance. If you take more distance you can just use the stick to change direction. Line up with your target before your there, and then make slight adjustments, or dont fire at all and go arround for another pass. If you cannot get the crosshairs on target you shouldnt fire and just go for another run. If you still want to get the enemy fast, do the high speed turn.

Press Z for a while till you hear the engine sound change, pull back on the stick and use tailrotor to left side for instance. Because your braking the tailrotor will eventually get enough airflow to turn the aircraft, you will turn directly 180 and do another run. Otherwise just bug out and return from another route.

By the way, most targets should be taken out from a stand off distance with hellfires anyway. Just pop up and masking and your ok.

Also the tailrotor of the blackhawk, cobra, mi-8/mi-17, just wouldnt have the needed power to turn the helicopter when flying at higher speeds. Because of the speed forwards the whole aircraft with all its weight needs to be changed, the tailrotor is configured to give you optimal power but its simply not enough when flying at high speed. Because the airflow is still going backwards because your moving forwards at high speed. Therefor you need to slow down in order to get proper tail rotor control.

I think the people who are complaining the hardest should instead of bitching in this topic, open their editor and fly some more.

I have NO problem what so ever with the current flight model, its very easy to do every turn, attack run, high speed landing etc without any difficulties or lack of realisme.

Just learn to fly!

And for fixed wing aircraft, the flight model was fucked in OFP allready and has improved with arma but still is fucked basicly, but everybody knows it. OFP and ARMA arent flight sims so get over it.

Besides this, addons that will be released when the tools are out, will change everything probally.

[subs17 9]

Quote[/b] ]You cannot make coordinated turns without rudder input - and FBW doesn't controll rudder for you.

Doesn't FLCS do this in modern jets?

Yes it does In Real Life

[subs17 9]

I don't see how you can say that rudder is rarely used in high speed aircraft.

Rudder input is just as common as it was back in the day of WW2.

You cannot make coordinated turns without rudder input - and FBW doesn't controll rudder for you.

You will have to use constant rudder adjustments in aircombat if you want to fly energy efficient.

Trim is used to keep the aircraft level and straight in flight.

Just because modern aircraft have automated trim doensn't mean that rudder is rarely used.

And speed of the airflow is completely irrelevant to rudder effectivness as an aerodynamic term.

It affects the needed input force on the controlls.

What we have now in ArmA is simply unrealistic.

Rudder changes the direction of movement - period.

The Fly by Wire FLCS does all that for you, can still use rudder though in situations such as landing in a crosswind etc. Try asking here

http://www.fighterops.com/

As I mentioned the A-10 still uses rudder in certain situations but in most F-16 sims its rarely used.

[Col.Flanders 0]

...but with helicopters your not supposed to use the tailrotor at higher speeds anyway.

Define higher speeds.

The way it is now, tail rotor starts to become ineffective at speeds of which some humans are capable of running at.

[Hunin 0]

I don't see how you can say that rudder is rarely used in high speed aircraft.

Rudder input is just as common as it was back in the day of WW2.

You cannot make coordinated turns without rudder input - and FBW doesn't controll rudder for you.

You will have to use constant rudder adjustments in aircombat if you want to fly energy efficient.

Trim is used to keep the aircraft level and straight in flight.

Just because modern aircraft have automated trim doensn't mean that rudder is rarely used.

And speed of the airflow is completely irrelevant to rudder effectivness as an aerodynamic term.

It affects the needed input force on the controlls.

What we have now in ArmA is simply unrealistic.

Rudder changes the direction of movement - period.

The Fly by Wire FLCS does all that for you, can still use rudder though in situations such as landing in a crosswind etc. Try asking here

http://www.fighterops.com/

As I mentioned the A-10 still uses rudder in certain situations but in most F-16 sims its rarely used.

I don't want to offend but please re-read my post.

I did not imply that the FCS canno't coordinate rudder input.

My point is that you are wrong about rudder beeing hardly used in high speed jets.

It is hardly used in normal flight yes - but to say rudder *may* be used *sometimes" in certain situations is not true.

In every single combat manouvre you will need to apply yawing motion manualy in one way or another.

Even the Typhoon has no completely automated rudder and it's FCS systems are by far superior to Block 52 Vipers.

As to the question what has to be changed pratically by BIS:

Seperate the plane and helo FM and get rid of the rudder ineffectivness at speed ( meaning setting this speed to a higher value).

If you want to have even more realism create true torgue; f.e. influence of collective changes to yaw.

[subs17 9]

Have a look here:

http://www.fighterops.com/forum....=rudder

[Hunin 0]

In capitals this time ( forgive me mods):

THE FCS DOES NOT AUTOMATE RUDDER INPUT: IT AUTOMATICALY REACTS TO CHANGES MADE TO THE OTHER INPUT DEVICES.

Another example to show you what I am talking about, just answer the question:

Can the F-16 make a barrel role? Yes/No?

[frederf 0]

as long as the tail rotor can produce enough torque to maintain the turn then it can fly at almost any angle. When it can't produce the required power it loses rudder authority and succumbs to drag. This means the aerodynamic forces caused by the fuselage will force the aircraft along its direction of flight. But only long enough until the tail rotor can produce enough torque to affect the turn again.

I'd suggest you do some research and learn how helicopters actually fly. Its quite interesting and should give you a far better appreciation of what’s being discussed.

Thank you for telling me I'm an idiot and then agreeing with me. I guess I'll just take my pilot's license and my degree in physics and go home.

A sideways flying helicopter does feel a weathervaning torque and there is some speed where the tail rotor is unable to keep the helicopter sideways. The post I was replying to stated (and I quote):

Quote[/b] ]Flying sideways does mean that airflow is now pushing against the side of the heli rather than the front, so the maximum speed obtainable without too much torque on the rotor depends on the aerodynamic qualities of the side of the heli, which is why some (such as the Hokum) are able to fly much better than others 'sideways.'

The maximum speed obtainable sideways depends on the weatherwaving torque and the finite ability for the tail rotor to counteract it, not the aerodynamic crosssection of the fuselage.

That being said there are about at least 3 very long, very long-winded threads on the aircraft yaw authority issue. It's been done to death. There's lots of informed people quite a few false 'facts' in the whole lot.

[Staos 0]

IF ARMA HAD A PERFECT HELICOPTER SIMULATION:

1. Player climbs into Kiowa.

2. Player clicks on the battery and fuel. Hits the starter.

3. Engine explodes.

4. Player gets out and climbs into next Kiowa on the flight line.

5. Repeat steps 2-4 until player figures out he's doing something wrong.

6. Player reads flight manual.

7. Not understanding what the words "hot start" mean, player attempts to start engine again.

8. Engine whirrs a little, then explodes.

9. Feeling discouraged, player hops into a nearby trabant to grab some fast food.

10. Player finds out he has destroyed $20mil in turbine engines, is unable to afford cheeseburger and fries, opts for two salt packets and a bullion cube.

I guess the moral of the story is: be careful what you wish for. Helicopters are VERY complex machines. Trying to figure one out is not "video-game fun". If BIS put in a complete aircraft simulation, people would be complaining it's too hard.

[frederf 0]

Hahah. <3.

Game design must of course be done with attention to the audience and the context that creates. It would be unreasonable to expect an F-16 pilot in ArmA to avoid venting Hydrazine vapors from the APU since the user is not a jet pilot but a gamer. However it is not unreasonable for the game to model the impossibility of a helicopter flying upside down.

The yaw authority of aircraft is well within the grasp of gamer pilots while entering all the IFF codes for the FAC Kiowa's laser designator is probably not. Not only is it within their ability to understand and adapt to, it's actually easier and more intuitive to fly.

There are of course gray zones between "reality for reality's sake uber unnecessarily complex sim" stuff and "arcade" but yaw authority is not one of them.

[Guest RKSL-Rock]

Thank you for telling me I'm an idiot and then agreeing with me. I guess I'll just take my pilot's license and my degree in physics and go home.

You're welcome.  I'll take my own pilot's licence, 378 hours flying, Aeronautical Engineering Degree and Masters in Aerospace Production and Design, not to mention 10+ years working in the aerospace industry and still call you and idiot.

And yes my cock is still bigger than yours.

You’ve just agreed with the original post you rubbished.  You demonstrated your knowledge by using a totally inaccurate and ridiculous analogy of a “bar-variety dartâ€.

The maximum speed obtainable sideways depends on the weatherwaving torque and the finite ability for the tail rotor to counteract it, not the aerodynamic crosssection of the fuselage.

Now while that is in part correct it’s not the whole story is it.  Whilst flying sideways the surface area of the fuselage will have more of an affect on drag on the “weathervaning effect†than just tail rotor torque.  There is, as you rightly say, a finite amount of torque available which in conjunction with the aerodynamic limits imposed by the drag of the fuselage will determine the max speed that the helicopter can fly sideways.  Torque alone is not the governing factor which is what you seem to want us to beleive.

That being said there are about at least 3 very long, very long-winded threads on the aircraft yaw authority issue. It's been done to death. There's lots of informed people quite a few false 'facts' in the whole lot.

I think this thread was more of an addendum to those debates, calling for a further change to the ArmA flight model, not one trying to disprove physics.  Personally I think it’s still a valid issue worthy of a fix at some point.

[subs17 9]

In capitals this time ( forgive me mods):

THE FCS DOES NOT AUTOMATE RUDDER INPUT: IT AUTOMATICALY REACTS TO CHANGES MADE TO THE OTHER INPUT DEVICES.

Another example to show you what I am talking about, just answer the question:

Can the F-16 make a barrel role? Yes/No?

Of course it can and yes the rudder can be used but as I stated its rarely used. Including dogfights you will see why when you check the above link. I agree with the idea of having separate FMs for each aircraft but the rudder depends on the aircraft type and how its used IRL.

[subs17 9]

Hahah. <3.

Game design must of course be done with attention to the audience and the context that creates. It would be unreasonable to expect an F-16 pilot in ArmA to avoid venting Hydrazine vapors from the APU since the user is not a jet pilot but a gamer. However it is not unreasonable for the game to model the impossibility of a helicopter flying upside down.

The yaw authority of aircraft is well within the grasp of gamer pilots while entering all the IFF codes for the FAC Kiowa's laser designator is probably not. Not only is it within their ability to understand and adapt to, it's actually easier and more intuitive to fly.

There are of course gray zones between "reality for reality's sake uber unnecessarily complex sim" stuff and "arcade" but yaw authority is not one of them.

Complexity can be scalable so arcade on some servers and more complex on others. I think the addition of an MFD with a slewable TDC which you can zoom, ground stabilise, lock and use TI would be cool and closer to the real deal with minimum effort than going the whole hog with a fully clickable 3d 6dof pit like Black Shark. Also a laser range finder would be good as well.