How does the rudders work?

[Stringfellow]

Whenever I use the rudders (I use the joystick's 'rotation') the helicopter just swirves back to it's original heading. I'm aware that the black shark will in hover mode automatically have it's nose towards the wind, but it resets itself so fast that I have really given up using the rudder when flying. Even just turning the helicopter in hover mode towards a target is annoying as the chopper instantly tries to revert to it's original position. Is it the autopilot? Have I misunderstood something? please help!

[hilikusopus]

Disclaimer: I am neither a physicist, nor an aerodynamics scholar!

 

But if the helo has a tendency to turn toward the wind then maybe it has a related tendancy to turn toward the direction of your movement. Say you're heading straight with some speed and apply some heavy rudder - even though you're orientation has changed, most of your momentum is still heading in the original direction due to inertia - when you recenter the rudder pedals the helo will tend to revert to the original configuration. I notice that this also happens in fixed wing simulators, as well. I wonder if it's the same principle as with rotary craft.

 

I'm curious about an intelligent answer to this question too!

?

Edited July 7, 2009 by hilikusopus

[Maulkin]

Yes there is a heading autopilot which has been the bane of my piloting existence. Look at the panel with the big square blue buttons... its the lower left one. :)

[Nate--IRL--]

For now, turn on the Flight director, blue button to the right of the 4 autopilot buttons, then start reading up on the trim and stabilisation systems. Brew a pot of coffee, it will be a long read.

 

Here's a start.......

http://forums.eagle.ru/showpost.php?p=572028&postcount=27

http://forums.eagle.ru/showpost.php?p=572028&postcount=33

[connos]

And here is a video explaining Trim

 

Note: Trim resets all Auto Pilot Chanels and this also includes your Heading Hold. Besicaly every time you change Heading Trim. Engadge rudder Trim. Always Dream oh sorry Trim.

[enigma6584]

Here is what I do. When I'm flying and want to turn in another direction. During the turn I will hold down the "trim" and release it when I'm at the heading I want to go. Of course when you do this, remember to center the cyclic quickly.

 

It is the same when making a turn in a hover. While twisting my joystick (i.e. using rudder pedals), I hold down trim until I'm pointing where I want to and then release trim. You have much more control of the aircraft this way.

 

I also believe (although just a guess on my part) that is what the real Russian Ka-50 pilots do. Just look where the trim button is located on the cyclic. Extremely easy and comfortable for them to utilize the trim while moving cyclic.

[Triggerhappy69]

These are just my own experiences from flying RC helicopters, a handfull of time flying real helicopters, and simulators.

 

The rudder pedals serve several functions.

 

They counteract the torque twisting motion:

Whenever you change your collective or cyclic input. And as such they never have a "fixed" center.. any small change in the collective will throw the yaw axis of balance, and you need to counter with the pedals.

 

They control your angle against sideways working forces when flying straight forwards:

Since helicopters are unstable systems by nature, any force working on the chopper will get you out of balance. Wind and the weathervane effect are the two forces most needed to be balanced when you fly straight forwards. Mainly you control this by keeping the "ball" under your HSI more or less centered (if your not in a side-slip that is). Failing to do this will put you in a position where your nose is pointing at your eleven-o-clock while your flightpath is at twelve-o-clock. In short your flying towards your waypoint slightly sideways. And burning more fuel that you need to.

 

making a constant speed turn in helicopters I have found is best done by rolling the chopper to the side your turn should be and then, while making sure you don't lose your angle of attack, forcing the chopper through the turn with your yaw pedals. Your collective, while in a turn like this, is used to maintain altitude, and if the roll angle is high enough you can apply some collective at the end of the turn to accellerate out of it.

In short for a left constant speed turn:

- Roll to the left.

- maintain your pitch angle of attack.

- force the chopper arround with your yaw pedals in a constant steady manner.

- use collective so maintain altitude (and as such also speed)

 

 

The chopper by nature doesn't even want to be airborne.! It's natural instinct is to plunge to the ground and dissintigrate..!

Flying it is more like balancing a ball on top of another ball. If you wayt to see what direction it moves, you'll be fighting it all the time. Much easyer to give the wrong input yourselves, and then knowing what you just did you simply give the opposite input. Forcing the ball to stay in place..?

[nomdeplume]

It's been discussed a lot and the post Nate linked to (twice?) is informative, so definitely read that. It also answers enigma6584's question about real Ka-50 pilots: they don't hold the trimmer button down.

 

However, real Ka-50 pilots don't have a slightly incorrectly implemented autopilot heading hold channel. I believe this is being fixed in the 1.0.1 patch. As I understand it, in the real Ka-50, the heading hold autopilot channel works out when you're actually trying to turn and updates the heading it's holding accordingly. In the currently simulated Ka-50 (1.0.0), the heading hold autopilot channel tries to hold the last trimmed heading. If you turn, it'll immediately start trying to turn back.

 

Therefore at the moment, you need to either hold the trimmer while you turn, use the flight director, or turn off the heading hold AP channel while you turn. None of these options are ideal. I'm looking forward to seeing how the Ka-50 flies with the modified heading hold logic.

[AlphaOneSix]

I am very familiar with the Mi-8/17 autopilot, and it actually "knows" when the pilot is giving control inputs, so doesn't counteract them. I have a hard time believing that the real Ka-50 doesn't behave similarly. Hopefully it will be something that we can get implemented/improved in the future, but since I personally don't have any access to the relevant documentation for the actual aircraft, I can't say how it really supposed to be, all I have to go on is my knowledge of the Mi-8/17 autopilot.

[hilikusopus]

cheers, fellas.

[ericinexile]

I am very familiar with the Mi-8/17 autopilot, and it actually "knows" when the pilot is giving control inputs, so doesn't counteract them. I have a hard time believing that the real Ka-50 doesn't behave similarly. Hopefully it will be something that we can get implemented/improved in the future, but since I personally don't have any access to the relevant documentation for the actual aircraft, I can't say how it really supposed to be, all I have to go on is my knowledge of the Mi-8/17 autopilot.

 

 

AHHH! A16, I've been waiting months for you to say this! (Perhaps you previously did and I missed it. If so, apologies...)

[AlphaOneSix]

Well for the Mil autopilot, it's fairly simple in concept. You have gyros that tell the autopilot the rate of attitude change, and the copilot's ADI tells the autopilot the amount of attitude change. It uses these two inputs to decide how much to affect the flight control servos in order to counteract the attitude change. Very simple, and this is what the game seems to do for the Ka-50 as well. But on the Mil autopilot, there are "compensation transducers" on the pitch and roll channels (I'll get to yaw in a second). The transducers are actually attached physically to the flight control tubes. So if you move the cyclic to the left, for example, to initiate a roll....well the roll gyro would send rate of change to the autopilot, and the ADI would send amount of change to the autopilot, AND the transducer send an OPPOSITE signal to the autopilot, canceling out the autopilot's tendency to fight the control input while still providing "dampening". If the pilot does not move the cyclic, the autopilot will attempt to hold the aircraft's attitude. For the yaw channel, it is slightly different. The pedals have microswitches in them to determine if your feet are on the pedals or not. If your feet are NOT on the pedals, the autopilot ssumes you want to hold your heading, and it will do everything it can (20%) to hold your heading (just like we currently see in the game). However, if you put your feet on the pedals, the yaw channel goes into "matching mode" and heading hold is disabled automatically, and the autopilot only performs dampening.

 

All of that only works if all of the autopilot channels (except altitude) are on. Of course, on an Mi-8/17, there is no flight director.

 

To me, the autopilot in the game *should* perform similarly to how I've described it above, but it doesn't, and I can't prove that it should because I don't have the documentation. If the AP *did* work like this, then all FD mode would do would be to give you symbology on the HUD. Again, this is just me copying and pasting my Mil knowledge onto my vision of how the Ka-50 should act...I have no way of knowing how it *really* acts.

[Nate--IRL--]

From what I've been able to understand the KA-50 operates much like the DCS Ks-50. I think the difference is down to the design philosophies between Mil and Kamov. Mil IMHO have got it right.

 

Nate

[ericinexile]

Well for the Mil autopilot, it's fairly simple in concept. You have gyros that tell the autopilot the rate of attitude change, and the copilot's ADI tells the autopilot the amount of attitude change. It uses these two inputs to decide how much to affect the flight control servos in order to counteract the attitude change. Very simple, and this is what the game seems to do for the Ka-50 as well. But on the Mil autopilot, there are "compensation transducers" on the pitch and roll channels (I'll get to yaw in a second). The transducers are actually attached physically to the flight control tubes. So if you move the cyclic to the left, for example, to initiate a roll....well the roll gyro would send rate of change to the autopilot, and the ADI would send amount of change to the autopilot, AND the transducer send an OPPOSITE signal to the autopilot, canceling out the autopilot's tendency to fight the control input while still providing "dampening". If the pilot does not move the cyclic, the autopilot will attempt to hold the aircraft's attitude. For the yaw channel, it is slightly different. The pedals have microswitches in them to determine if your feet are on the pedals or not. If your feet are NOT on the pedals, the autopilot ssumes you want to hold your heading, and it will do everything it can (20%) to hold your heading (just like we currently see in the game). However, if you put your feet on the pedals, the yaw channel goes into "matching mode" and heading hold is disabled automatically, and the autopilot only performs dampening.

 

All of that only works if all of the autopilot channels (except altitude) are on. Of course, on an Mi-8/17, there is no flight director.

 

To me, the autopilot in the game *should* perform similarly to how I've described it above, but it doesn't, and I can't prove that it should because I don't have the documentation. If the AP *did* work like this, then all FD mode would do would be to give you symbology on the HUD. Again, this is just me copying and pasting my Mil knowledge onto my vision of how the Ka-50 should act...I have no way of knowing how it *really* acts.

 

You know, I think I've confused you with EvilBivol, who I argued with a few months back about this. On the forum you two look like twins :D.

 

Anyway, isn't it easy enough to find a Ka27 pilot/mechanic/manual to get a definitive answer on Kamov FCS philosophy? Whatever happened to AirTito, btw?

[AlphaOneSix]

Anyway, isn't it easy enough to find a Ka27 pilot/mechanic/manual to get a definitive answer on Kamov FCS philosophy? Whatever happened to AirTito, btw?

 

Easy is relative, I suppose. Easy for some, not so easy for others. I've been trying, but no luck so far. AirTito has taken a hiatus from the forums, but I think he pops in occasionally. He left his job working with Kamovs, I think, and moved on to another job working with fixed wing aircraft.

[ArchAngel]

rudder

 

Stringfellow, this is how I fly and its very easy.

 

b4 takeoff, disengage alt hold, I believe its the lower right blue button, and engage flt director. U will find that flying this way is easy. as u fly watch the ball and make corrections to keep it center. if u r on a long flight then center the ball and hit trim. bware that u may have to hit trim several times until u have the yaw center and the pitch/roll center. when going into a hover or b4 doing any sort of manuevers simply disengage trim.

 

holding the trim button while manuerving is, in my honest opinion not necessary at all.

 

hope this helps.

 

Peace.

[slug88]

holding the trim button while manuerving is, in my honest opinion not necessary at all.

 

That's because you fly with FD on. The whole point of holding the trim while maneuvering is to temporarily enable an FD-like state for the maneuver, and then disable it as soon as the maneuver is completed. Obviously, there's no point in temporarily enabling an FD-like state if it's already on at all times.