Aircraft Rudders

[hailstorm 4]

Since OFP, there has been this problem with the rudders on aircraft - but since, in my opinion, it was really hard to judge what direction the player was actually flying in at any given time, it was hard to notice. however, with the advent of the flightpath being marked on the HUD of aircraft, it's quite obvious - aircraft rudders are completely, absolutely detatched from reality.

in ArmA, if you use the rudder at speed, you'll notice the aircraft body slew to the left/right... then nothing! all the rudders apparently do in ArmA is to twist the airframe 5 degrees to the side - and keep it there, while the aircraft flies off to the side! if anyone, ANYONE can name me a fixed-wing aircraft that has rudders that do this, i'll give 'em a cookie!

in fact, i'm sure that everyone who has flown a real plane or even an R/C one will say that Rudders, besides keeping a plane in-balance during a banked turn - will, if used exclusively, end up turning a plane around in circles - it has the same effect as every other flight control on a plane (ailerons for roll, elevators for pitch) - it creates a force that acts on the airframe and results in it changing alignment. anyone who has witnessed - or, even better, flown - a 'stall turn' will tell you the force a rudder can have on an aircraft.

to put it simply, the real effect is more like the steering of a car - if you twist the steering wheels, the body of the car - and direction - turns. the same applies with rudders. twist the rudder, the body of the aircraft turns in the same manner, along with it's engines (and therefore the thrust line), and the aircraft begns to turn like a car, more or less. this, in it's basic form at least, is what i want to see in ArmA.

Coming from a fixed-wing background, i'm not very knowledgeable about helicopters, but coming from a fluid dynamics point-of-view, i do question the total lack of rudder on helicopters going at speed. true, there is an aerodynamic force that prevents a helicopter from going side-on to it's flightpath if moving at speed - but hang on, for a helicopter tilting forwards and using rudder to turn, wouldn't the flightpath change as well as the direction of the body? the direction of the rotordisc is directly attached to the airframe, so if you rotate the airframe and keep the stick where you left it, shouldn't the rotordisc change angle too, and coupled with that, the flightpath?

simply put, Rudders act to twist the airframe, and can, if so used, change an aircraft's flightpath - not to point weapon launchers offset to the flightpath.

vote on this issue in the bugtracker:

Lack of constant, authorative rudder control on all aircraft

[bravo 6 0]

i done my part

[memnoch 0]

Not sure if it is speed related by I have always seen the same thing. Hold left or fight, the nose will slowly point in that direction but you won't start move round and will return to the original heading once released. Just keep an eye on the compass strip at the top to confirm.

[frederf 0]

Quote[/b] ]in ArmA, if you use the rudder at speed, you'll notice the aircraft body slew to the left/right... then nothing! all the rudders apparently do in ArmA is to twist the airframe 5 degrees to the side - and keep it there, while the aircraft flies off to the side! if anyone, ANYONE can name me a fixed-wing aircraft that has rudders that do this, i'll give 'em a cookie!

in fact, i'm sure that everyone who has flown a real plane or even an R/C one will say that Rudders, besides keeping a plane in-balance during a banked turn - will, if used exclusively, end up turning a plane around in circles - it has the same effect as every other flight control on a plane (ailerons for roll, elevators for pitch) - it creates a force that acts on the airframe and results in it changing alignment. anyone who has witnessed - or, even better, flown - a 'stall turn' will tell you the force a rudder can have on an aircraft.

In my 100 hours as a fixed wing pilot I have always experienced the rudder authority to mostly just yaw the aircraft's heading without actually changing its course. Mash on the rudder pedal and the nose slews around but the airplane keeps on going the direction it used to. Let off the the rudder and the nose snaps back to where it used to be like it was on a rubber band.

Yes it is possible to do a "skidding turn" with rudders alone but it will be a 0.5 deg/sec turn or something very small. Any amount of bank will totally dwarf the effects of even full rudder authority at speed. You'd fly totally off the map 3 times over before you could do a successful 180 degree turn in any of the ArmA jets by rudder alone.

In my opinion the rubber-band nose-rudder thing is entirely correct it's just the way that rudder authority relates to speed is off in ArmA. For both airplanes and helicopters the weather vane tendency is far too high and abrupt. Mashing on the rudder at high speed in a helicopter should give you 3-5 deg of yaw not 0.25 deg.

Substitute the words "tail rotor authority" for "rudder" when referring to helicopters above. I don't think any of the rotor aircraft in ArmA have rudders.

[scudrunner 0]

Rudder input in fixed winged aircraft has a rubber band effect initially do to momentum, but keeping the rudder down long enough will certainly change the direction of the aircraft. Pulling a 360 with rudder and keeping bank steady would take quite some time, but certainly as long as exaggerated above- and of course it'd depend on speed. The rudder effect could certainly be strengthened without objection in fixed winged aircraft.

[hailstorm 4]

In my 100 hours as a fixed wing pilot I have always experienced the rudder authority to mostly just yaw the aircraft's heading without actually changing its course. Mash on the rudder pedal and the nose slews around but the airplane keeps on going the direction it used to. Let off the the rudder and the nose snaps back to where it used to be like it was on a rubber band.

Yes it is possible to do a "skidding turn" with rudders alone but it will be a 0.5 deg/sec turn or something very small. Any amount of bank will totally dwarf the effects of even full rudder authority at speed. You'd fly totally off the map 3 times over before you could do a successful 180 degree turn in any of the ArmA jets by rudder alone.

In my opinion the rubber-band nose-rudder thing is entirely correct it's just the way that rudder authority relates to speed is off in ArmA. For both airplanes and helicopters the weather vane tendency is far too high and abrupt. Mashing on the rudder at high speed in a helicopter should give you 3-5 deg of yaw not 0.25 deg.

well, yes, ideally banking would be preferred to yawing in most situations, but there are cases where you need rudder - for example, very low and with the wings rolled over 90 degrees, or trying to fine-tune aim of the guns on the fighter jets - which, especially in the case of the A-10, would have oversized rudders for increased effectiveness.

Planes DO NOT 'keep going in the direction they used to" when rudder is applied, they WILL change course - I remember recieving a 'stern lecture' from my flight instructor for attempting to turn a trainer using only the rudder - coupled with my aerobatics experience, where i learnt both stall turns and four-point rolls, which both involve stomping on the pedals at the right moments -  i know for a fact that rudders can be in cases considered a primary flight control.

like scudrunner said, the 'rubber-band' effect is due to momentum, same as any other flight control - ever notice you have to begin to level out, or begin to roll wings level, before you actually have to? same reason why the nose feels like it 'snaps back' when you let go of the pedals - and in addition your sense of balance also has an effect, as you're used to twisting around, you think the nose is going in the opposite direction when it stops.

The problem in ArmA is that Rudders/tail rotor authority currently has ZERO effect on flightpath - which is simply not true. the image i placed on the bugtracker page shows this off clearly - I Placed the A-10 straight down the runway (for a reference point) and put in left rudder for four seconds - enough to show that the flightpath does simply not change - i could hold on the rudder across the whole map, and my flightpath will be straight as an arrow.

What i want to see is that the initial turning effect slightly reduced from what it is now, but have the nose motion followed through with a change in flightpath.

[subs17 9]

Decent HOTAS support has my vote as with both collective with the throttle and rudder axis for the tail rotor. (with that it would probably be possible to adjust the sensitivity of the rudder axis)The thing is that tail rotor input is constant to fly helicopters. It needs to be applied in response to increased power from the main rotors. If they add HOTAS support then I'd be really impressed as no FPS has ever crossed that line. Just one other thing the targetting for helicopters it would be nice to have a realistic MFD targetting display and also to be able to use the HAT on my stick to slew the TDC onto targets, ground stabilise and lock. That would be cool as an addon anyway.

[max power 21]

HOTAS is supported.

[subs17 9]

Yup as I just discovered, this game rocks now.

[Gisen 0]

The fidelity of the controls is just awful. The aircraft - planes and helis - don't fly well from a gameplay point of view OR from a realism point of view. And please, don't anyone claim that better flight modelling would be too hard on the engine: there are better flight models in games DECADES old such as "A-10 Cuba" or "Enemy Engaged Apache Havok". You can almost run these games on a mobile phone, there is no reason arma can't have flight models half as good as these games.

[subs17 9]

Compared to other FPS games out there the FM for Armas helicopters is the best I've seen so far. I can still pull loops and rolls with the Cobra. I haven't tried the hog out yet but when I do I'll be able to compare it to lockons as I've spent a fair bit of time using the hog in lockon. From a realism perspective I think the weapons employment from the helicopters could be better if we could use a proper optical sight on an mfd and also couple that with zoom, ground stabilise and lock with laser for hell fires. I know that in OFP there was the ability to paint a target from the ground for lgbs. It would be good if the Kiowa could do this for the cobras hellfires(if someone were to make one for it).

[hailstorm 4]

I think the flying model needs work, but simply saying that won't really help the situation - what i'm aiming to do is place several things into the bugtracker, pointing out what needs to be changed - the most important one i figured that hasn't already been mentioned was the lack of rudders/tail rotor authority, hence this thread and BT listing.

i placed a image onto the bugtracker page itself showing what the ArmA aircraft do when you put rudders in. today i went and did the same thing, only in a different flight sim - this was my result:

Rudder Effect

a nicely curving left-hand turn, ending with me crashing into the tower that appears in the last few seconds of the clip.

in addition, in This Video (19mb), at about the 1:25 mark, you can see that the pilot flies a right-hand turn using only rudders.

it's simple. rudders DO effect an aircraft's flightpath.

[jasono 0]

I think they got all the rudder sorted and thought "look at it, rudders are working!".. but it's just an illusion of some kind that they are.

I doubt any of the BIS coding team are real pilots so they wouldn't know the exact effect of rudders. But, your right, it doesn't do what it's meant to do therefore a pointless feature.

Add in the next Patch please BIS?

[BLUEmako 0]

simply put, Rudders act to twist the airframe, and can, if so used, change an aircraft's flightpath - not to point weapon launchers offset to the flightpath.

Simply put, your post is completely wrong.

As previously mentioned, rudders alone do not turn an aircraft.

If you keep a rudder deflected the main effect is side slip. There is in some aircraft a secondary roll effect but in no circumstances will rudder alone cause an aircraft to turn.

That said, the entire flight model in ArmA is woeful and the modelling of the rudder controls appears to be reasonably accurate more by luck than anything else...

As far as helicopters go, while moving forwards the anti-torque rotor will cause the aircraft to point in the direction of the pedal you push. However, as soon as you release the pedal the chopper returns to it's original heading. The amount of deflection you get is a function of the forward speed, aerodynamics and the power of the tail rotor. Generally the faster you go, the less deflection you get. I can go through the theory but suffice it to say that I've done it in practice and it's also a standard part of heli pilot training.

Please note though that use of these controls can affect your ground track, but this is a very different thing to your aircraft heading.

If anyone wants to debate these points, it's probably worth noting that I have a degree and 10 years experience as an Aero Engineer IRL.

'nuff said.

[Col.Flanders 0]

Yes but at 40/50km/h you could fly a blackhawk or littlebird sideways if you wanted. (ie. from flying forward at 40km/h, then full use of pedal, the aircraft would still rotate 90 degrees on the rudder axis and keep it's original direction of motion even if it slowed down.)

The ArmA flight model brings in that aerodynamic effect at too low a speed whereby the design of the airframe is forced head-on into the wind because of its aerodynamic properties.

Put this to the test - take off in a helo in ArmA. Give a cyclic input so that you begin to move either directly left or right with no forward or backwards movement. See how fast you can go before the nose flicks into the wind. Now take off and fly forwards. Take half the speed that was required for the nose to be forced into the wind on the other test and apply full rudder. Does anything happen? My guess is probably not or very very little.

My point is that up to a given speed, you should have some rudder authority so as to be able to attack ground targets accurately with rockets even at relatively low speed. (say 60-80km/h) It's just not the case in ArmA. As it stands, every helo with weapons has to be used either in a hover, or like the Hind where you run in at full speed requiring you to be lined up from miles out.

The numbers I've used here in my post aren't all down to the meter per second. Some of them I've used simply to illustrate my point. I'm sure i'll be shot down in flames nonetheless - but that's just a heads-up.

My vote goes to bugtracker.

[hailstorm 4]

from what i can gather, the programmers believe the rudder functions the way it does because of how pilots use yaw to counteract wind - although not realising that there is no wind component in ArmA (and ignoring the fact that pilots dont have to hold the rudder to do so). coming from an airplane point of view, it is possible to use a rudder to turn - while not the most efficient means to do so, it can be done.

in the same manner a rudder is used to turn a large ship, if you keep a rudder deflected, it creates a force on the tailplane (or stern) to shift it in the opposite direction to the way the rudder points. this rotates the airframe (hull), along with it's thrust line, resulting in a change of direction. if the rudder is held in the same position, it keeps turning, and so does the direction of the craft.

yes, there is a bit of a roll generated because one wingtip is going faster than the other, but lets get the programmers to fix the primary effects first, eh? then maybe, if the flight models are looking somewhat respectable, then we'll think about those finer points...

[Aurvan 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

[subs17 9]

from what i can gather, the programmers believe the rudder functions the way it does because of how pilots use yaw to counteract wind - although not realising that there is no wind component in ArmA (and ignoring the fact that pilots dont have to hold the rudder to do so). coming from an airplane point of view, it is possible to use a rudder to turn - while not the most efficient means to do so, it can be done.

in the same manner a rudder is used to turn a large ship, if you keep a rudder deflected, it creates a force on the tailplane (or stern) to shift it in the opposite direction to the way the rudder points. this rotates the airframe (hull), along with it's thrust line, resulting in a change of direction. if the rudder is held in the same position, it keeps turning, and so does the direction of the craft.

yes, there is a bit of a roll generated because one wingtip is going faster than the other, but lets get the programmers to fix the primary effects first, eh? then maybe, if the flight models are looking somewhat respectable, then we'll think about those finer points...

Rudder is used in fixed wing aircraft to coordinate turns as if you turn without using them the aircraft is actually slipping sideways. The exception to this though is fast moving aircraft such as the F-16 which hardly use rudder at all although they do use trim as the fly by wire system takes care of it.

[LeftSkidLow 1]

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

You can fly sideways in an ArmA helicopter, up to around 180 kmph. It has to be initiated from a hover otherwise it wont work, but its more of a quirk in the flight model than a feature.

[hailstorm 4]

Rudder is used in fixed wing aircraft to coordinate turns as if you turn without using them the aircraft is actually slipping sideways. The exception to this though is fast moving aircraft such as the F-16 which hardly use rudder at all although they do use trim as the fly by wire system takes care of it.

of course - that's usually what the rudder is most prominently used for - to keep the aircraft in balance, however, it doesn't mean you cannot turn using just the rudders.

have a look at the "Rudder Effect" vid link i posted before - it's actually from an F-16 simulator. if that thing can turn, why not other jets?

[ID7 0]

twist the rudder, the body of the aircraft turns in the same manner, along with it's engines (and therefore the thrust line)

Thrust and momentum are the key factors here. Thanks to the momentum (or the force of the wind) it is possible to fly with nose pointed in a direction different from the flight path. Depending on the level of thrust and other factors, the rudder affects flight path. The effect is demonstrated in the aerobatics video you have posted. Many times in the past the rudder has been the life-saver of aircrafts with damaged ailerons.

[subs17 9]

Rudder is used in fixed wing aircraft to coordinate turns as if you turn without using them the aircraft is actually slipping sideways. The exception to this though is fast moving aircraft such as the F-16 which hardly use rudder at all although they do use trim as the fly by wire system takes care of it.

of course - that's usually what the rudder is most prominently used for - to keep the aircraft in balance, however, it doesn't mean you cannot turn using just the rudders.

have a look at the "Rudder Effect" vid link i posted before - it's actually from an F-16 simulator. if that thing can turn, why not other jets?

Yes I have that sim thats Falcon 4 as I stated rudder is rarely used in real life in high speed aircraft such as F-16s. In falcon I rarely use the rudder unless the aircraft is damaged although I do use the rudder occassionally in lockon in the A-10 for example to help adjust my aim whilst straffing. Trim however is something all aircraft use.

[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.

[Pulverizer 1]

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?

[MehMan 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.