DCS: AH-64D Flight Model discussion

[Rogue Trooper]

No curves.

No Saturation

Just raw analogue input. centre stick, 10cm cyclic extension on my airframe.

Balance the cockpit's centre sill to horizon as you increase collective, This is Roll I am talking about.

Balance roll via the pedals only. Right pedal leans left and left pedal leans right.

Start pedal right, as you increase collective, smoothly increase the left pedal to balance the airframe's natural roll to righ( ignore the hover digital display), keep increasing left pedal as you increase collective. hold the centre sill level with the horizon. 

Increase collective until wheels light. ensure your centre sill is horizontal with the horizon. When the roll is done right, you will simply drift off the ground..... it is all pedal work with this girl.

The airframe will naturally hang right low & tail low in hover.... but this will become apparent as you drift off the ground and may need simple cyclic adjustment.

I just think she is the best chopper in DCS!

Hover and BoB up digital displays are advisory only, what you are hiding behind is the primary point of reference in day light.

Night time manoeuvres is whole different level!

 

Edited June 26, 2023 by Rogue Trooper

[kdfw]

the cyclic is very sensitive to the touch, you barely move it and the helicopter moves about.  

so, in the real thing, how does one fly it with turbulence and g-forces without losing control? 

maybe the controls are way too sensitive?  the mass of the aircraft and the large 4 blade rotating disk should offer inertia and gyroscopic stability...

[Sandman1330]

On 6/26/2023 at 11:05 PM, kdfw said:

the cyclic is very sensitive to the touch, you barely move it and the helicopter moves about.  

so, in the real thing, how does one fly it with turbulence and g-forces without losing control? 

maybe the controls are way too sensitive?  the mass of the aircraft and the large 4 blade rotating disk should offer inertia and gyroscopic stability...

Helicopter controls are extremely sensitive in hover, it’s realistic. It is exacerbated by the controls most players have at their disposal - short joysticks with limited throw increase sensitivity even more. Extensions help. You can also adjust saturation in the axis settings (I do not advocate curves), saturation will reduce your maximum range of motion but the extreme edges are rarely needed anyway (exception being forward pitch, you may run out of forward authority in fast forward flight).

Try and hover like we do in the real thing - set yourself up so your wrist is resting comfortably on something. We use our leg with a center cyclic, if you have a side mounted joystick try and use the arm of your chair or something. Rest your arm comfortably, relaxed, and control the stick with just fingertip control. Don’t move the controls, just ‘think’ about moving the controls. The rest is just practice

[TZeer]

I can only echo what @Sandman1330 is saying.

I have done what he mentioned. Centerstick, extension and resting my arm on my leg, and using fingertips to do corrections. No fatigue, better control, fine adjustments etc.

And use the visuals OUTSIDE the cockpit much more. Changing to the "hover" symbology to early just makes you chase the instrument. No point in using the symbology if your not first able to keep it realitvely stable just using the visual cues from outside the cockpit, at least in my opinion. Helped my quite a bit.

Currently just flying around on Nevada, in hilly areas. Going from cover to cover, practicing the transition from forward flight to hover, just using the visuals, and trying to keep the same altitude.

Very easy to go from 50-60 feet and suddenly be 10 feet of the ground when you finally have come to a hover

[kdfw]

8 hours ago, Sandman1330 said:

Helicopter controls are extremely sensitive in hover, it’s realistic. It is exacerbated by the controls most players have at their disposal - short joysticks with limited throw increase sensitivity even more. Extensions help. You can also adjust saturation in the axis settings (I do not advocate curves), saturation will reduce your maximum range of motion but the extreme edges are rarely needed anyway (exception being forward pitch, you may run out of forward authority in fast forward flight).

Try and hover like we do in the real thing - set yourself up so your wrist is resting comfortably on something. We use our leg with a center cyclic, if you have a side mounted joystick try and use the arm of your chair or something. Rest your arm comfortably, relaxed, and control the stick with just fingertip control. Don’t move the controls, just ‘think’ about moving the controls. The rest is just practice

Thanks for the comments!

I'm using a vkb stick with 4" extension and my wrist is resting on my leg for my sim setup.  Also using cyclic saturation at 50% to take advantage of the dynamic range of the stick.

With this setup, the AH is pretty stable to control with two fingers on the grip but I'm sitting on a stationary chair. 

What with the real AH in flight making tactical takeoff/landings with the wind buffeting the aircraft, controlling the stick with finger tips would be pretty much impossible with this kind of control sensitivity?

For this model, it seems mass of the aircraft and gyroscopic stability are not quite there.  Control response shouldn't be instantaneous to the touch as the rotor blades flex with change to control input.

I guess I don't like the twitchiness of the cyclic for such a heavy double turbine 4-blade beast of a helicopter--a mellower AFCS modulated control is what I was expecting. 

Whining aside, it's still a blast to fly though.

[Phantom_Mark]

Even whilst flying with tons of consideration for rotor speed, vortex, and all the other stuff we have to worry about flying choppers I continually find myself dropping out the sky like a stone or spinning around wildly because I ran out of available torque because of the amount of torque being used by the rear rotor to remain stable or kick the rear to do basic turns, I don't feel this was so prevalent in the past ?? 

Is this totally just me or some of the improvements we might see in later flight model evolutions ?  I know how the trim works and use it continually to make sure I don't run out of trim options 

[admiki]

32 minutes ago, Phantom_Mark said:

Even whilst flying with tons of consideration for rotor speed, vortex, and all the other stuff we have to worry about flying choppers I continually find myself dropping out the sky like a stone or spinning around wildly because I ran out of available torque because of the amount of torque being used by the rear rotor to remain stable or kick the rear to do basic turns, I don't feel this was so prevalent in the past ?? 

Is this totally just me or some of the improvements we might see in later flight model evolutions ?  I know how the trim works and use it continually to make sure I don't run out of trim options 

TR has plenty of authority. Are you sure you are not overweight for conditions?

[Poptart]

The TR won't have much authority at higher speeds. You should bank and turn once you're over about 30knots. Adding more pedal at higher speeds will just sap power from the main rotor.

[Phantom_Mark]

9 minutes ago, admiki said:

TR has plenty of authority. Are you sure you are not overweight for conditions?

Maybe, I tend to just have rockets and 8 missiles onboard ,nearly always this happens when I am at low speed either positioning behind a tree line or in preparation for landing, I find things go from super stable and predictable to completely out of control in an instant.

[admiki]

24 minutes ago, Phantom_Mark said:

Maybe, I tend to just have rockets and 8 missiles onboard ,nearly always this happens when I am at low speed either positioning behind a tree line or in preparation for landing, I find things go from super stable and predictable to completely out of control in an instant.

And full fuel? Yeah, that sounds like you are overweight.

[Phantom_Mark]

I just checked, 80% weight

I am starting to wonder if it because I have a habit of turning left at low speed rather than using the natural torque to turn right ??? 

Edited July 9, 2023 by Phantom_Mark

[Raptor9]

56 minutes ago, Phantom_Mark said:

I just checked, 80% weight

Just to clarify, the weight ratings in the mission editor are based on structural limitations, not performance limitations. If the aircraft is loaded to 20,000 pounds, that is below the maximum gross weight the aircraft is structurally rated for, but that does not mean the aircraft has sufficient power-to-weight ratio to carry such a payload. Even if it can, it may not be able to maintain a hover until it burns off fuel or expends munitions.

[Phantom_Mark]

5 hours ago, Raptor9 said:

Just to clarify, the weight ratings in the mission editor are based on structural limitations, not performance limitations. If the aircraft is loaded to 20,000 pounds, that is below the maximum gross weight the aircraft is structurally rated for, but that does not mean the aircraft has sufficient power-to-weight ratio to carry such a payload. Even if it can, it may not be able to maintain a hover until it burns off fuel or expends munitions.

So what you are saying is there is zero issues related to.........thank you.

[SloppyDog]

7 hours ago, Phantom_Mark said:

Maybe, I tend to just have rockets and 8 missiles onboard ,nearly always this happens when I am at low speed either positioning behind a tree line or in preparation for landing, I find things go from super stable and predictable to completely out of control in an instant.

Do you have the mission you are flying or a track file? Altitude and temperature play a crucial role when trying to hover or land.

[Phantom_Mark]

On 7/10/2023 at 2:00 AM, SloppyDog said:

Do you have the mission you are flying or a track file? Altitude and temperature play a crucial role when trying to hover or land.

So I spent a good deal of time flying around empty in the same situation, just fuel onboard with gun rounds. 74% weight iirc.

Most of my troubles seem to stem from trying to stop the chopper torque rotate to the right at low speed, basically just run out of rotor speed / and / or engine power , its the speed that it departs that makes it super hard to predict sometimes ??  the amount of times I have literally just dropped out the sky like a stone would defy the hours I invested and the effort I make not to create my own bad situations from bad choices.

No track atm - maybe I make one later, and still as ever happy to concede maybe I just suck.

[Floyd1212]

39 minutes ago, Phantom_Mark said:

run out of rotor speed / and / or engine power

You are keeping your throttles at FLY and only adjusting the collective, right?  Sounds like maybe you are reducing power on the throttles and l causing a low RPM situation?

[Phantom_Mark]

9 hours ago, Floyd1212 said:

You are keeping your throttles at FLY and only adjusting the collective, right?  Sounds like maybe you are reducing power on the throttles and l causing a low RPM situation?

Nope, normally the only time that throttle moves from fly is to boost the engines to get some extra rotor speed if it starts to dip below 95%,  if if when descending I end up with high rotor speed and over speeding the engines - else it sits continually on fly, slightly OT it seems quite amazing there is not an automatic throttle which keeps all that stuff in unison / optimal

[Floyd1212]

7 minutes ago, Phantom_Mark said:

slightly OT it seems quite amazing there is not an automatic throttle which keeps all that stuff in unison / optimal

There is.  That's what the FLY position is for.  Once you bring it from IDLE to FLY during your startup, don't touch it again.

You just need to be slow on the collective to let the engines keep up and not let the rotor system over-/under-speed.

[SloppyDog]

14 hours ago, Phantom_Mark said:

So I spent a good deal of time flying around empty in the same situation, just fuel onboard with gun rounds. 74% weight iirc.

Most of my troubles seem to stem from trying to stop the chopper torque rotate to the right at low speed, basically just run out of rotor speed / and / or engine power , its the speed that it departs that makes it super hard to predict sometimes ??  the amount of times I have literally just dropped out the sky like a stone would defy the hours I invested and the effort I make not to create my own bad situations from bad choices.

No track atm - maybe I make one later, and still as ever happy to concede maybe I just suck.

Thanks for the info.

That's really strange. Tackling this problem piece by piece, what I can think of is that you are inputting too much collective while trying to hover. Very powerful helicopters like the Apache and the Hind have the similar problem: if excess collective is inputted, the torque in the main rotor becomes too strong to be counteracted by the tail rotor, thus they start to rotate. Then it is very easy to lose control, and as you are already at maximum collective or above, trying to input more collective just adds to the control issue, and it will fall out of the sky.

The second part to the problem is that you may having problems with control bindings or curves. Maybe you are moving the collective and it is moving another control (as the throttle), or you are moving any other control and it is adding to the collective. 

I use curves to diminish some of the crazy reactions that the Apache and its SAS control have when maneuvering. 

The dead zones at the end of the collective axis are there because my throttle control is old and has some looseness at the end, thus this way I guarantee having 100% control of the collective. For the other axis this 100% control is not needed, and a very smooth curve with a high saturation allows for a more controllable aircraft.

COLLECTIVE AXIS

CYCLIC X AXIS

CYCLIC Y AXIS

RUDDER AXIS

Edited July 11, 2023 by SloppyDog
Adding subtitles to the controls axis pictures

[Grennymaster]

there is a sort of auto throttle system. but i dont remeber the name

the bird need to be flown realativly gentle the whole time. you can do hard stuff but this takes a lot of praktice. in transition from flight to hover you have to be very gently with the collektiv. if your sink rate is to high you will get in the VRS an lose the bird.

it will take time to learn but you will get into it. espezialy with helos, slow is presice and prescise is fast

 

[SloppyDog]

6 minutes ago, Grennymaster said:

there is a sort of auto throttle system. but i dont remeber the name

the bird need to be flown realativly gentle the whole time. you can do hard stuff but this takes a lot of praktice. in transition from flight to hover you have to be very gently with the collektiv. if your sink rate is to high you will get in the VRS an lose the bird.

it will take time to learn but you will get into it. espezialy with helos, slow is presice and prescise is fast

 

The "Auto-throttle" in helos is called a governor. 

It automatically injects more or less fuel to compensate for the changes in the angle of attack of the blades, thus more or less drag, in order to try and maintain rotor speed constant.

[Phantom_Mark]

I will get some tracks up at some point, but I am mostly focussed on the idiot in the cockpit at the moment, to try and self analyse if I am merely causing my own problems.

One observation I have tho, which may be related.

I was in a nice stable hover at around 50ft, deliberately trying to provoke the departure so I could better understand why and when etc, after trying to oversaturate the torque by using a ton of pedal to the left etc I resumed a normalised hover and then decided to have a little practice at lowering my height without excessive rotor speed, as usual I got Rotor Speed High warning and then started observing the engine percentage, it was sat around 45 on both engines, nothing out the ordinary there, as I am doing all these flights empty now so I can rule out the weight, then I started to enter a little bit of a vortex ring or ground effect , this was despite a very very very subtle and gentle descent rate, then it happened, I dropped out the sky like a stone because the moment I started to drop the engines were too slow to respond to my input, I visually saw I was going into a bad space and immediately went full power and added a little collective to get away from the ground........nada.......I will try and do it again but this but only increasing the engine speed next time ?

I have no real issues flying around or hovering at all, its just these sudden unrecoverable moments where you fall out the sky like a stone...I have def identified my preference for circling left on a low approach & turn doesn't help, so that is one pilot induced risk reduced at least ?

Edited July 11, 2023 by Phantom_Mark

[Floyd1212]

12 minutes ago, Phantom_Mark said:

immediately went full power and added a little collective

Again, it looks like you are messing with both the throttle (power) and the collective.  Leave the throttles at FLY and only use the collective.

If you enter VRS and the helo starts to shudder and shake as you drop out of the sky, you need to use the cyclic to fly out of your vortex; forward, sideways, backward, whatever.  Just adding in more collective will often not allow you to recover.

If you are in a hover and you want to descend, lower the collective slightly and take your time on the descent.  Once you get your vertical speed dropping too fast, VRS is likely to follow.

[admiki]

33 minutes ago, Phantom_Mark said:

I will get some tracks up at some point, but I am mostly focussed on the idiot in the cockpit at the moment, to try and self analyse if I am merely causing my own problems.

One observation I have tho, which may be related.

I was in a nice stable hover at around 50ft, deliberately trying to provoke the departure so I could better understand why and when etc, after trying to oversaturate the torque by using a ton of pedal to the left etc I resumed a normalised hover and then decided to have a little practice at lowering my height without excessive rotor speed, as usual I got Rotor Speed High warning and then started observing the engine percentage, it was sat around 45 on both engines, nothing out the ordinary there, as I am doing all these flights empty now so I can rule out the weight, then I started to enter a little bit of a vortex ring or ground effect , this was despite a very very very subtle and gentle descent rate, then it happened, I dropped out the sky like a stone because the moment I started to drop the engines were too slow to respond to my input, I visually saw I was going into a bad space and immediately went full power and added a little collective to get away from the ground........nada.......I will try and do it again but this but only increasing the engine speed next time ?

I have no real issues flying around or hovering at all, its just these sudden unrecoverable moments where you fall out the sky like a stone...I have def identified my preference for circling left on a low approach & turn doesn't help, so that is one pilot induced risk reduced at least ?

 

Quite a lot of things don't add up here. Please, post a track.

[corbu1]

vor 6 Stunden schrieb Phantom_Mark:

Nope, normally the only time that throttle moves from fly is to boost the engines to get some extra rotor speed if it starts to dip below 95%,  if if when descending I end up with high rotor speed and over speeding the engines - else it sits continually on fly, slightly OT it seems quite amazing there is not an automatic throttle which keeps all that stuff in unison / optimal

You should always stay the throttle n fly. You are sure you don‘t have mixed control bindings or move the throttle to lock out position? What is your setting for lock out detend in the AH64 special options tab?