DCS: AH-64D Flight Model discussion

[Rhinozherous]

Is the weird skidding bug adressed in todays update?

[dedlike.]

did i miss something durring todays patch ? the heli feels realy wobbly now its kinda hard to explain, especaly int he pitch axis, its realy bad, but in a different way as to how it used to be

[Belphe]

15 hours ago, TZeer said:

Getting light on the wheels, countering the yaw with my pedals. At the same time I need to put in cyclic to prevent the skidding. But as you get light enough and takeoff, the Apache almost wants to tip over.

Yes, same here and it makes sense (although just as Casmo says, it is wrong). We have to apply so much left cyclic to counter the right slide that we load the left wheel way past what should be reasonable. The only thing that holds us motionless is the friction of that left wheel against the surface and if we choose to lift off slowly the aircraft will tip over. Doing it faster will likely induce a left drift which needs an instant counter to the right. Wiggle wiggle wobble wobble

[unairspace]

7 hours ago, dedlike. said:

did i miss something durring todays patch ? the heli feels realy wobbly now its kinda hard to explain, especaly int he pitch axis, its realy bad, but in a different way as to how it used to be

I believe the FM remains unchanged. Wobbly +1

[GrEaSeLiTeNiN]

23 hours ago, Belphe said:

Yes, same here and it makes sense (although just as Casmo says, it is wrong). We have to apply so much left cyclic to counter the right slide that we load the left wheel way past what should be reasonable. The only thing that holds us motionless is the friction of that left wheel against the surface and if we choose to lift off slowly the aircraft will tip over. Doing it faster will likely induce a left drift which needs an instant counter to the right. Wiggle wiggle wobble wobble

Hmm.. after watching Casmo's vid, I decided to do a quick test. The takeoffs seemed smooth to me. Just a little left cyclic and very little left pedal. Did I miss something? Track attached. (Latest Open Beta, MT version.)

 

Apache Take-Offs.trk

[Belphe]

Awkward, I actaully have to add right pedal now during takeoff... 

[TZeer]

@Belphe axis been inverted in the setup?

[Floyd1212]

7 hours ago, GrEaSeLiTeNiN said:

Hmm.. after watching Casmo's vid, I decided to do a quick test.

I also messed around with it a bit after watching his video and couldn't replicate the behavior exactly as he was showing it.  I could get a little slip going once I got light-on-wheels, but not a maintained slide across the tarmac.  If I was on the ground, the tires would stick.

Maybe it's time for him to do a repair, or reinstall?

[Raptor9]

Casmo's claims that these are wrong behaviors are not accurate. The Apache experiences translating tendency to the right in real life as well, as it will also rotate in place on the ground if the tail wheel is unlocked and tail rotor thrust is applied in an unbalanced fashion. As was stated on the previous page, the tail rotor is producing positive thrust when the pedals are centered in the yaw axis, and must be applied slightly to the right in an offset manner to actually zeroize the tail rotor thrust.

If left cyclic is properly applied to counter the right rolling motion and the right translating tendency from the high-mounted tail rotor, the aircraft will lift straight up. In a no winds situation and with a symmetric loadout, the AH-64 will always lift the right wheel off the ground before the left if the takeoff is performed properly. Just as is the case with any other maneuver or flight condition in a helicopter, if the forces that are being applied to the helicopter are out of balance, the aircraft will respond in an unbalanced manner. If translating tendency is not countered by the pilot, the aircraft will start to slide to the right as it gets very light on the wheels and continue drifting right after liftoff. Although this typically results in the main landing gear tires sort of skipping across the ground if the aircraft is light enough to lift up without inducing a dynamic rollover.

EDIT: "Light on the wheels" is typically described as approximately 20% torque below IGE hover power. Once you start increasing power above this, you will be in a weird region where the aircraft is essentially flying, but has not fully cleared the landing gear from the ground due to the shock struts extending as the aircraft weight comes off the landing gear. This is the prime region for inducing dynamic rollover and should be avoided by continuing to increase power to IGE hover power or reducing the power to fully land and compress the landing struts. You do not want to "dance" around on the ground in this region in real-life nor in DCS.

Edited June 10, 2023 by Raptor9

[SloppyDog]

1 hour ago, Raptor9 said:

EDIT: "Light on the wheels" is typically described as approximately 20% torque below IGE hover power. Once you start increasing power above this, you will be in a weird region where the aircraft is essentially flying, but has not fully cleared the landing gear from the ground due to the shock struts extending as the aircraft weight comes off the landing gear. This is the prime region for inducing dynamic rollover and should be avoided by continuing to increase power to IGE hover power or reducing the power to fully land and compress the landing struts. You do not want to "dance" around on the ground in this region in real-life nor in DCS.

 

Cool. So what I am doing is not entirely wrong: I usually get Light on the Wheels about 40ish percent, then if I continue to apply collective in a slow manner, it will rollover. Then what I'm doing now is press on with the collective at about 70%, it will come off of the ground and will be stable. The thing I've noticed since last patch is that now it takes 10% more torque to lift off that I was used to, now it is about 70%, before it was a cool 60%.

[pii]

On 6/9/2023 at 1:56 AM, Belphe said:

Yes, same here and it makes sense (although just as Casmo says, it is wrong). We have to apply so much left cyclic to counter the right slide that we load the left wheel way past what should be reasonable. The only thing that holds us motionless is the friction of that left wheel against the surface and if we choose to lift off slowly the aircraft will tip over. Doing it faster will likely induce a left drift which needs an instant counter to the right. Wiggle wiggle wobble wobble

I've said it before and I'll repeat it when low and slow to me it's like I'm in a boat on rough water rocking back and forth. 

[pii]

On 6/9/2023 at 2:51 AM, unairspace said:

I believe the FM remains unchanged. Wobbly +1

it's changed but the slow-speed handling has gotten really bad! 

[bond672]

I have made a couple of videos on the latest apache flight model in doomsdayfriday. The one below was before the changed the FM again. 

 

Until it gets re-examined? I'm parking her up, I can't deal with the unpredictability of her.

Simon. 

[Raptor9]

Just to prevent any confusion or mixed information out there, the flight model received no updates on this most recent patch, nor did the SCAS or hold mode logics. If anyone is seeing anything different, I recommend examining your control options to see if anything has changed.

The last time the flight model received an update was in the mid-May Open Beta update.

[bond672]

That's the one I was using in the video. Once airborne, she flies so much better. I noticed a difference, but.. Slow speed, transition to a hover? It's so much harder. I have to use George to hold any sort of hover. 

[Poptart]

Yaw seems really active in a hover. Even small changes in collective result in 10 degree swings even with a little pedal input. I'm not even sure what SCAS is doing. It's almost easier to hover with trim interrupt. There is a huge onset of right torque as soon as you slow to 15 knots. It comes on really suddenly and feels unrealistic. 

Edited June 10, 2023 by Poptart

[Raptor9]

40 minutes ago, Poptart said:

There is a huge onset of right torque as soon as you slow to 15 knots. It comes on really suddenly and feels unrealistic. 

Just as the main rotor becomes less efficient as you slow below ETL (16-24 knots), the tail rotor experiences the same drop in efficiency for the same reason. The need to apply anti-torque input to counter the increase in collective performed to maintain altitude as the aircraft comes to a hover is correctly exacerbated by the fact the tail rotor is also becoming less efficient.

[GrEaSeLiTeNiN]

I am ok with the takeoffs but do notice the increased rocking back and forth when attempting OGE hover. 

[TZeer]

8 hours ago, bond672 said:

That's the one I was using in the video. Once airborne, she flies so much better. I noticed a difference, but.. Slow speed, transition to a hover? It's so much harder. I have to use George to hold any sort of hover. 

Just some feedback to you.

- You are using to much stick when correcting. This can be hard with the Warthog base, specially if you also have a short stick. I have used that base myself, and it's a PITA with helicopters. Also, even with a much smoother base, I do not hold my entire hand around the cyclic. Very easy to induce to much correction to the cyclic. Doing small corrections I only use my thumb, index and middle-finger. You should also have something to rest your arm on. Makes it much more comfortable, and when only using the three fingers I mentioned, much easier to hover.

- After you activated your "Hover-Hold", you kept moving your stick. This will override your "HOLD" if you move past 2,5%?? I think it was. Basically you are overriding any input the "HOLD" mode wants to do. Just try to hover as best you can do, hit "HOVER" and let go of the stick, to prevent you moving the stick.

- Another thing that can help you, move the trim-commands to a hat that is easy to reach and don't interfere with your cyclic inputs. Specially if you are not able to rest your hand. It's very easy to induce unwanted cyclic inputs when trying to reach whatever hat you have assigned your trim to, if it's on your cyclic. Personally I have an extra trim button on my pinky on the collective, that I use when I'm transitioning from forward-flight to hover. This is until I get an extra part on my setup that I can lower my cyclic so I can properly rest my arm on my thigh when flying. This makes it easier for me, as I can use tiny corrections coming into hover, while holding my trim button on the pinky switch. When I'm happy I can use my "hover-hold" command on my cyclic as normal.

[skypickle]

I have found scas to be more powerful. Using the trim button seems to not only give a sloppy stick but also suspends scas. I am using a rhino ffb stick.

Pressing the ‘show controls’ hotkey’ twice shows pilot inputs on the top left and scas inputs on the top right. During flight the scas tends to oppose pilot inputs but as soon as the trim button is depressed there are wild positional changes as the pilot’s unopposed inputs affect the aircraft.

 

similarly, lifting to hover is a totally different experience depending on whether or not the trim button is held down.

 

This makes the apache more difficult than the huey. In the uh1 there is no scas so holding the trim button only gives a sloppy stick. Your muscle memory remains valid so the chopper keeps its attitude. In the apache, the minute you depress the trim button, not only does the stick get limp, but that invisible ‘assistant’ disappears so you have to immediately change your inputs just to maintain the same attitude. Keeping the ball centered helps minimize this disconnect in yaw and roll but there is no indication for pitch. 
 

i realize scas is added to help stabilize an inherently labile airframe/powerplant design, but the added layer of complexity is challenging to fly if you forget the significance of the effect of scas.

[bond672]

9 hours ago, TZeer said:

Just some feedback to you.

- You are using to much stick when correcting. This can be hard with the Warthog base, specially if you also have a short stick. I have used that base myself, and it's a PITA with helicopters. Also, even with a much smoother base, I do not hold my entire hand around the cyclic. Very easy to induce to much correction to the cyclic. Doing small corrections I only use my thumb, index and middle-finger. You should also have something to rest your arm on. Makes it much more comfortable, and when only using the three fingers I mentioned, much easier to hover.

- After you activated your "Hover-Hold", you kept moving your stick. This will override your "HOLD" if you move past 2,5%?? I think it was. Basically you are overriding any input the "HOLD" mode wants to do. Just try to hover as best you can do, hit "HOVER" and let go of the stick, to prevent you moving the stick.

- Another thing that can help you, move the trim-commands to a hat that is easy to reach and don't interfere with your cyclic inputs. Specially if you are not able to rest your hand. It's very easy to induce unwanted cyclic inputs when trying to reach whatever hat you have assigned your trim to, if it's on your cyclic. Personally I have an extra trim button on my pinky on the collective, that I use when I'm transitioning from forward-flight to hover. This is until I get an extra part on my setup that I can lower my cyclic so I can properly rest my arm on my thigh when flying. This makes it easier for me, as I can use tiny corrections coming into hover, while holding my trim button on the pinky switch. When I'm happy I can use my "hover-hold" command on my cyclic as normal.

Thanks you so much for this feedback, means a lot. I use the warthog throttle but I use the Vkb evo stick with no extention. I was thinking of changing my saturation levels? 

Simon. 

[Floyd1212]

2 hours ago, bond672 said:

Thanks you so much for this feedback, means a lot. I use the warthog throttle but I use the Vkb evo stick with no extention. I was thinking of changing my saturation levels? 

 

You can start by setting a curve of maybe 20, then using a y-saturation of 70 or 80. This will definitely reduce the overall performance envelope of the aircraft if you were to try and make aggressive maneuvers, but it will help you with the finesse needed for hovering and low-speed flying.

Once you have a hang of hovering and landing with these settings, take the y-saturation back out a bit at a time over a few sessions until you are used to each step of the way. You will adapt at each step and train your muscle memory back to a 100 y-saturation level.

I fly with a 20cm extension with a curve of 15, and extremely light springs with minimal center detent, and it still takes very minimal adjustments to the cyclic when hovering and landing.

[bond672]

31 minutes ago, Floyd1212 said:

You can start by setting a curve of maybe 20, then using a y-saturation of 70 or 80. This will definitely reduce the overall performance envelope of the aircraft if you were to try and make aggressive maneuvers, but it will help you with the finesse needed for hovering and low-speed flying.

Once you have a hang of hovering and landing with these settings, take the y-saturation back out a bit at a time over a few sessions until you are used to each step of the way. You will adapt at each step and train your muscle memory back to a 100 y-saturation level.

I fly with a 20cm extension with a curve of 15, and extremely light springs with minimal center detent, and it still takes very minimal adjustments to the cyclic when hovering and landing.

I had looked at an extension but I mainly fly fast jets so I was rather hesitant to specialise with an extention. I will try the saturation advice and see how I get on. 

Simon. 

[Rogue Trooper]

For me the Apache is all about Pedal work at take off.

If you get the pedals wrong as the collective increases then the entire airframe tilts.

If the airframe tilts, then the main rotor tilts, if the main rotor tilts then you are increasing a massive force in the direction of the tilt. There is no give in the swashplate... only solid Hydraulic oil.

A touch of left trim on the cyclic and pedals to level roll as the collective increases is all that is needed.

If I remember correctly right pedal leans left and left pedal leans right.... I tend to apply it as I see it.

Edited June 12, 2023 by Rogue Trooper

[MustangSally]

My 0.02 cents....

I'm now finding the Apache relatively easy to fly since changing saturation and adding a slight curve to my pitch and roll. I've also removed the springs and just added dampers to my Orion 2. Removal of the spring centering on my MFG pedals has made a vast improvement to directional control. Just love it now....oh and btw, Casmo was a big help

Edited June 12, 2023 by MustangSally