AH-64D Apache - Issues with pitch as 'Pilot'

[Toni Carrera]

Hi All,

I have managed to sort out my Anti-Torque issue now, but I have a significant issue with Pitch

In order to just maintain level flight, you can see by the attached image, how much forward stick I have to apply, just to try and maintain level flight

I am trying to avoid using Trim at the moment, as that just makes everything worse. The problem is that as soon as I  get airbourne pretty much, my nose is pointing to the sky, and I am fighting to keep it down as you can see from the control axis in the top right, so rather than nice controlled flight, I am spending most of my time looking out the window pretending I am a Kangaroo

I am constantly centering my TrackIR whilst in flight. One thing I have noticed, if it is relevant in anyway, is that I seem to be sitting quite high in the cockpit on start. I have to reduce the physical height of my head by scooching down in my chair, and reducing my cockpit head height with RCTRL+RSHIFT+NumPad2, to get anywhere near being able to BoreSight my IHADSS. Makes it worse that I have to do it every time I restart the flight, not sure if I can save it so I do not keep having to do it. I have tried without TrackIR and the same issue is there

I am not sure if you can tell by my image whether or not my cockpit head is at the right height. Like I said though, my biggest issue is the fact that I am having to apply so much forward stick, just to keep the nose down, even to just stay level in height, but because I am doing that, I have no real ability to control my speed. As soon and I box the speed, it immediately disengages and I also get the tone

Please can someone help me with this, the aircraft is unflyable as is. I do not get this issue in the UH-1, SA-342 etc

Thank you for your attention

Toni

[frostycab]

At 132 knots with 82% torque that amount of forward cyclic seems perfectly normal to me. Cruising along 100 knots with less torque reduces the necessary cyclic input by quite a bit. Engaging ATT hold mode doesn't do a lot that I can see right now, but I understand it's still WIP.

The Apache was never known as a particularly fast helicopter, so for now my advice would be just to slow down and take it easy.

[Floyd1212]

What do your curves look like for your cyclic?

[frostycab]

11 minutes ago, Floyd1212 said:

What do your curves look like for your cyclic?

I put a +10 curvature on both axes just to get slightly better fine control when hovering.

[Toni Carrera]

I do not want to travel fast, I want to be slow if anything, the problem is that I am spending so much time pushing forward, that the speed is all over the place. I can assure you that even at around 60 kts, in order to keep the aircraft from pitching nose high (a lot), I have to keep the stick way forward

The image I selected to show was, the last I took of 7. I will reduce the curve in options to 10 and repost image

[frostycab]

1 hour ago, Toni Carrera said:

I do not want to travel fast, I want to be slow if anything

Then I don't understand why you're hooning around at 135 knots.  

These pictures show my controls at speeds of 135kt (to compare with yours), 90kt and 60kt. All were in fairly stable level flight using the aircraft configuration from the Caucuses Runway Start instant action mission. As you can see, at lower speeds you need very little cyclic input to keep things stable, but cyclic deflection seems to increase exponentially at higher speeds. Even if I'm in a rush I won't push her past around 115 to 120kt. Also take note of the engine torque. At high speed you really have to rag it, but ease off a bit and it comes back to a comfortable low to mid range.

If you want to jump into MP sometime and we can see what you're doing wrong in real time then let me know, but I suspect it's just a case of needing some more practice and perhaps a bit of guidance. Let me know.

 

[Toni Carrera]

OK, well I do not wish to enter in to an argument about it, so I will just pull back from my question. I can assure you at lower speeds, 60's to 90's, I have the issue where naturally the helicopter sits way above the transition line and I have to maintain a huge amount of forward pitch to just keep the crosshairs on the dashed line

Worry not, I will just get my Stream Deck profile done for the CPG that some are waiting for, and go back to the F/A-18C

Apologies for wasting everybody's time in reading this thread

Toni

[frostycab]

Don't apologise. You asked for help and we're trying to give it, but to do that we need to understand the "why it's happening part." Without actually seeing it the problem is very hard to diagnose. I've done my best in the above post, but you're saying that's not the issue, so we just need to look at other possibilities. You say this is happening at in the 60-90 knot range. Is your stab trim in AUTO? I know it reverts to AUTO above 80 knots regardless, but if for some reason it's in a nose-up trim then that could be causing issues.

EDIT: Had another though. Have you been into the axis bindings and confirmed that nothing went out of whack with the last update? I'm thinking a conflict on your pitch axis with another physical axis. It's a slim chance, but it's happened to me in the past.

Edited April 2, 2022 by frostycab
Typos

[Toni Carrera]

@frostycabI suppose that I was trying to make out that I do not hoon about at large speeds, in reality, I would rather control my speed and arrive late, than give it the full beans and die en route. I know the picture provided did not show that, but that is what I find happens after I have been flying a while, the speed just creeps up and up, because I almost feel like I have the pitch full forward at times to stop it pointing at the moon

 

Well I thought that too about the axis, but I tried pulling out everything but the joystick and collective, both of which are TM product, HOTAS Warthog and Stick (using F/A-18C add-on grip

As for the stab, not a 100% on that, I will check in next flight. I have tried resetting all controllers, and axis, but the same occurs. It just seems to always want to be nose high whatever I try.

I will gather some more information and provide on here. I feel though, with all aircraft I fly, I work almost at times with decimals of degrees. I am so gentle on the controls, and not a yanker and banker, just a so gentle, as I have been when flying real helicopter, granted not a military one. I work on the 'Slow is smooth, smooth is fast' methodology, always trying to avoid pilot induced oscillation

One question, when you are flying the Apache, say at 40kts and release the stick, what does the helo do, with zero trim. What does your nose do?

Toni

[frostycab]

7 minutes ago, Toni Carrera said:

One question, when you are flying the Apache, say at 40kts and release the stick, what does the helo do, with zero trim. What does your nose do?

Give me 15 minutes and I'll do a flight and upload a track.

[Zap921]

1 hour ago, Toni Carrera said:

OK, well I do not wish to enter in to an argument about it, so I will just pull back from my question. I can assure you at lower speeds, 60's to 90's, I have the issue where naturally the helicopter sits way above the transition line and I have to maintain a huge amount of forward pitch to just keep the crosshairs on the dashed line

Worry not, I will just get my Stream Deck profile done for the CPG that some are waiting for, and go back to the F/A-18C

Apologies for wasting everybody's time in reading this thread

Toni

Toni, I think I understand what you're seeing and think when referring to the pitch ladder or "crosshairs on the dashed line".  The crosshairs on the dashed line does not correlate from airplanes to helicopters.  What you're looking at is only the attitude of the aircraft in relation to level flight.  This works fine for airplanes telling you that your nose is aiming towards the ground or headed towards the sky.  Works the same in helicopters as far as where the nose is pointed but the faster a helicopter flies the more the nose wants to dip down (to a point) because the blades above you are dragging you forward unlike an airplane which is pulling the aircraft straight forward.  In your first pic, at that attitude and torque you are actually going down about 300fpm so you could pull back on the cyclic more which would even up your crosshairs.  Don't pay so much attention to that and more on your Torque, Airspeed, and Rate of Descent.  Frostycab was right in his explanation.  Airplanes vs. Helicopters are really different when it comes to flying them.  Hope that makes some sense.

Depending on your loadout, outside air temp, altitude, wind, etc. that pitch ladder may never be lined up exactly the same at a given airspeed, close maybe.  An airplane can and should be trimmed out to fly the way you picture it for level flight, unless maybe your load is to far forward/back.  

[frostycab]

OK, I've got 2 tracks for you, one long one in the Apache, and a shorter on in the Huey for comparison. 

On the Apache track you can see that there's very little cyclic deflection needed to maintain stable flight at 40-60 knots, though the deflection require does increase significantly around  80 or 90. Above 100 the deflection required increases dramatically. At low speeds there was some pitch up motion when releasing the cyclic back to center, but nothing dramatic. At high speeds I got the expected "reach for the sky" effect, again as expected. Towards the end of the flight I tried a few more times with and without ATT hold mode engaged, as I don't normally use it right now and thought I'd see how it affected things. It did actually manage to correct the low-speed pitch increase within a couple of seconds of stick release, and returned pretty much to where I'd have wanted it. (I'm not sure if it's something you need to turn off and on again when you want to settle at a different speed/attitude, so best to check with one of the SMEs for that.)

You 

On the Huey track you can see that it pretty much exhibits the same behaviour, being relatively stable below 70 knots, but if you push the speed up then you get a bigger reaction when you center the cyclic. 

How does this compare to what you're seeing when you fly? Can you maybe get us a track to look at?

P.S. Please forgive the slovenly standard of direction control in my tracks. There was a cat that thought my rudder pedals looked particularly comfortable and decide to defend it's new-found napping zone. I do not own a cat, so this was very hard to get my head (and feet) around.

pitch test UH-1H.trk pitch test.trk

EDIT: Another thing just occurred to me. Taking your original post as an example, you say you get a huge pitching up motion if you return the cyclic to the center. What are you doing with your collective when this happens? I just did a quick flight and noticed something that I seem to do naturally. I start to dump collective just before I ease back on the cyclic. Not doing so does induce a massive pitch up motion, but if I start to drop the collective first and then ease back on the cyclic as a countermotion using the flight path vector as a reference then the pitching is fairly easy to control. Afraid it was about a 20 minute flight and you can only really notice it at the end so I didn't bother saving the track but next time out I'll try to do a short demo to see if that might be what's happening.

I should add that everything I've said in this thread is stuff I'd say if advising someone who's not overly familiar with flying helis in DCS. For all I know you may be a total rotorhead, so forgive me if any of these suggestions sound condescending. I have no measure of your level of experience to go on, so I write as if I'm dealing with someone who's a bit new to it.

Edited April 2, 2022 by frostycab

[Toni Carrera]

@frostycab Firstly, thank you for taking the time and effort to produce the trk files for me, as well as such an informative post

Secondly, do not worry about being condescending, did not even occur to me that you were being so, therefore I guess you weren't in my eyes. As far as I am concerned, you can treat me as if I were 10. I am about 40 years older than that, but I would take advice from a 10 year old if it were relevant. I have no ego to bruise. I guess it is just frustrating that I can fly the UH-1 and the SA-342 without any issues at all, which is what led me to my comment about feeling like the Apache is out of control, and something in my setup is very wrong. I have got use to the collective and yaw, and that annoying flight characteristic where all of the sudden, ever though you are not minimums on the collective, you seem to lose all list, and she starts to drop like a stone

@Zap921 I too thank you for your detailed and lengthy response, Looking at it from the perspective you applied to my brain, I can see what you mean, however, there does seem to be 'some' correlation between the cross and the dashed line, albeit not an official characteristic, but if I manage to keep it on the line, with virtually no other input, she will maintain a constant speed, within a few kts either side, when down around the 40's to 60's

I have downloaded the tracks, and will watch them both tonight, if I can keep my damn eyes open, so it may be at 7am tomorrow

Again, thank you both for your inputs and the efforts you have made on my behalf. I will report back when I have seem that which needs watching, and have some decent to say

Toni

[frostycab]

No problem. My offer of a multiplayer flight still stands. It might be the simplest way to sort things out.

[Leg2ion]

Hi @Toni Carrera - been playing with AH over the last few days - and can only but empathise! What seems good in one situation goes completely wrong in another. I ended up setting up custom curves (reference here) - and not generic - which give me a 'softer' central control position for yaw/pitch/roll - but also give me a linear input above a certain value. These have definitely improved my general handling....

Would also suggest setting up a local mission to play with 'on finals' landings - to get use to the sensitivity/reactivity of the collective for landing practice.

When I initially started I set up a mission at High Altitude in the test range - oh how so twitchy. I then set up another mission in Caucasus - completely different handling characteristics...

 

[Toni Carrera]

Morning All,

I can confirm that adding the cyclic manual curve as suggested by Leg2ion, as well as the advice from frostycab and zap921, and I am now in position where she is significantly more stable, even so much that I WAS Upped the Gun and managed a drive by shooting of a BTR and 2 bad guys

Anyway, off to a mission where I can practice the landing approaches as suggested

I thank you all for your effort and support, and time invested helping me with this issue

@frostycab I will take you up on your offer maybe later down the line, I am very nervous in talking to people, and especially so when I am making myself look like a rookie idiot

Toni

[frostycab]

32 minutes ago, Toni Carrera said:

Morning All,

I can confirm that adding the cyclic manual curve as suggested by Leg2ion, as well as the advice from frostycab and zap921, and I am now in position where she is significantly more stable, even so much that I WAS Upped the Gun and managed a drive by shooting of a BTR and 2 bad guys

Anyway, off to a mission where I can practice the landing approaches as suggested

I thank you all for your effort and support, and time invested helping me with this issue

@frostycab I will take you up on your offer maybe later down the line, I am very nervous in talking to people, and especially so when I am making myself look like a rookie idiot

Toni

Glad you're feeling more confident with it today. My offer is always open, and don't worry about talking much. I'm not exactly much of a chatterbox with new people myself. I also fly much, much worse when I know somebody is watching! LOL

[Zap921]

Good to hear Toni!  It will come with time, it's a different animal compared to an airplane.  Nice long approaches to your landing spot of choice, keep your airspeed around 60knts and below 500fpm descent.  This will vary of course but don't worry about the crosshairs, you should be starting your flare between 50-100ft and that is where your speed starts decreasing below 50-60knts.  You'll get it and then you'll get a big smile on your face!  Good luck....

[Toni Carrera]

@Zap921 Thank you, I am just doing some StreamDeck XL work and then I will do some flying later

Toni

 

[Toni Carrera]

@Zap921 Do you happen to have to hand the mission for long run in approaches that you used?

Toni

[Zap921]

I created a mission in the Caucasus Map with about 4 waypoints and some ground targets in the area of each waypoint for practice.  It starts cold/dark to practice startup with the Apache and it's located on one of the airports.  No traffic or nothing to speed you up, but a runway and parking on airports are great for picking a spot in the distance and learning to descend from given altitudes and hitting the spot that you picked.  Fly by your spot and then make u-turns and land where you picked.  Also there is a mission someone else created in the downloads section that would be great for you.  It has training squares in it that are in the air and it makes you fly through them stressing the co-ordination between cyclic, collective, and pedals.  Believe it had ones that make you land to.  I can look later if you like and let me know if you want that simple mission I created.  The enemy is my mission will shoot back if you get close enough but at least you know where they are and can practice.

[Zap921]

Well, I looked and can't find the training mission that makes you fly through green squares in the sky at certain speeds, banking, landing, etc..  I know I"m not dreaming maybe it was X-Plane.