DCS: AH-64D Flight Model discussion

[placsea]

On 4/14/2023 at 10:05 PM, admiki said:

I see only altitude hold drift here?

Which makes sense. If you look at collective channel, you can see FMC increasing collective until it runs out of authority. Reason that is happening is your helicopter increasing speed. Increasing speed will decrease lift.

Yes because the attitude hold is drifting, meaning the altitude hold has to compensate and quickly reaches it's authority limit as the aircraft continues to pitch down. Everything is stable when I trim and engage the hold modes then the pitch SCAS green cross creeps forward incrementally. This behaviour occurs with or without the altitude hold engaged.

Edit: Problem was me 

Edited April 18, 2023 by placsea

[Raptor9]

2 hours ago, Toge said:

The first reply by NineLine to the comments about the latest patch seemed more dismissive to me, and that's where my reaction comes from.

He wasn't being dismissive; he was stating facts in response to claims by users, as I had earlier in this very same thread over the previous weeks.

If a person states something that is incorrect, the listener has no way of knowing that the speaker meant something else. Therefore, if the person hearing the original claim refutes it, they are not being dismissive; they are responding to the original statement as framed by the person stating it.

[admiki]

Just now, placsea said:

Yes because the attitude hold is drifting, meaning the altitude hold has to compensate and quickly reaches it's authority limit as the aircraft continues to pitch down. Everything is stable when I trim and engage the hold modes then the pitch SCAS green cross creeps forward incrementally. This behaviour occurs with or without the altitude hold engaged.

For me, your attitude seems to be steady. I don't see any nose drop. You speed was increasing before you activated holds. 

Try to pull nose just a fraction up and test again what will happen.

[Raven434th]

To put it simply before vs after patch....I'm more fearful of the apache itself flying it than I am of the enemy I'm engaging. That should speak volumes.

[GremlinIV]

3 hours ago, admiki said:

For me, your attitude seems to be steady. I don't see any nose drop. You speed was increasing before you activated holds. 

Try to pull nose just a fraction up and test again what will happen.

 

So this raises a question about the Holds...

1. When you press ALTitude hold  at 200 feet in a slight nose up and it climbs to 210 feet, does the SCAS settle it at 200 feet? or? - couldnt think of an alternative..

2. If you press ATTitude hold at 100 knots and it rumbles to 105 knots does the SCAS lift the nose slightly to hold 100 knots? or? - same as above what is the alternative..

3. If you bump ALT hold at 200 feet and ATT at 100 knots within a second of each other within reasonable margins, does the SCAS compensate? - if not what does it do?

Then - I would assume the Collective SCAS kicks in in someway to assist with the 1, 2 hold requests as an individual condition,

and for 3, would then choose requested ALT hold as priority over ATT hold, and slow the helo rather than a slow descent into the ground (within its parameters)

Are we over expecting Holds to act like an "auto-pilot~ish" - StabilisationCAS would make you think it was "capable~ish"

This is of course a simplified question, aware there is also the additional work on YAW by the Tail rotor for all 3 scenarios affecting available power etc

Going to the Video posted above of a slowly increasing speed and loss of altitude to the point the collective is saturated, im suprised the SCAS didnt say, "hey we are going faster than requested and lower than requested and the collective is saturated, should we pull the nose to get back to the requested parameters AND reduce saturation of the collective?"

It seems once saturated there is no de-saturation without pilot interaction..

Do i have a misunderstanding of the SCAS, if I do then it needs an explanation at some point, starting with, do i need all my parameters to be exact before i use Hold/Holds... or can i expect the parameter at the time of pressing the Hold to be acheived/maintained thorugh the SCAS - (within reason, ie nose down dive click ALT Hold - Crash likely)

In general im talking about using Holds for Straight level flight on a heading or a gentle orbit, at reasonable speeds, for the hold modes, not zing zang combat stuff..

Also  i am aware, im not a SME,or a RL pilot, and its EA, 

Are we entertained......

Hmm didnt know how to add quotes,,, still not sure so hash it with an edit

 

Edited April 14, 2023 by GremlinIV

[admiki]

39 minutes ago, GremlinIV said:

1. When you press ALTitude hold  at 200 feet in a slight nose up and it climbs to 210 feet, does the SCAS settle it at 200 feet? or? - couldnt think of an alternative..

It tries to, but if your climb is too severe, it will run out of authority

39 minutes ago, GremlinIV said:

2. If you press ATTitude hold at 100 knots and it rumbles to 105 knots does the SCAS lift the nose slightly to hold 100 knots? or? - same as above what is the alternative..

No. Speed hold mode works only up to 40 knots. After that, it is pure attitude mode.

39 minutes ago, GremlinIV said:

3. If you bump ALT hold at 200 feet and ATT at 100 knots within a second of each other within reasonable margins, does the SCAS compensate? - if not what does it do?

See above

40 minutes ago, GremlinIV said:

Are we over expecting Holds to act like an "auto-pilot~ish"

Yes.

[GremlinIV]

Ah thx dude that explains alot - i will fly with these expectations in future

[pii]

17 hours ago, M1Combat said:

I didn't ask you to remain silent sir :).  I asked you to be nice, and it was simply asked because the world needs more nice and less rude.

Your post was clearly an obvious jab at what you think was a release that shouldn't have happened because it made something subjectively worse for you and it was also made from a "high horse" as it were.  It's fine to see it that way...  that's not a problem...  but some snide comment about it doesn't change the fact, doesn't help anyone and only serves to add to negativity.

 

So be nice ;).  Please :).

You seem overly sensitive.

xxoo

[Nereid]

23 hours ago, Raptor9 said:

People tend to see what they want to see

Indeed. That's why a was imprecise about my feelings about the changes over the last few patches. I think I saw a huge difference between my experiences from last year and my experiences now. But I can not really tell what exactly was different but it felt easier and without surprises in behavior in flight.

And I did a quick test with the new update this week. For me it looks more or less the same as last week. But it was a quick test only - ten to twenty minutes, not more and without attitude or altitude hold. And as admiki said: those are not like an autopilot in a jet.

The only thing that irritates me (but it did this since the AH-64D was  released), is that in a hover takeoff the bird tends to fall to the right - until it is in the air. Then any compensation for this will suddenly drift you to left. But maybe there is an explanation for this. But every day I try the AH-64D I need a little practise to get used to it.

[Raptor9]

28 minutes ago, Nereid said:

The only thing that irritates me (but it did this since the AH-64D was  released), is that in a hover takeoff the bird tends to fall to the right - until it is in the air. Then any compensation for this will suddenly drift you to left. But maybe there is an explanation for this.

You are probably seeing translating tendency. The combination of the main rotor torque and the tail rotor thrust will cause the AH-64 to translate right in a hover. Below is an image from the upcoming manual revisions, which will include better explanations of these concepts, among others.

When stationary on the ground, as you apply left pedal you should notice the aircraft starts to roll to the right from the thrust acting upon the top part of the vertical tail from the increase in tail rotor thrust. With the aircraft on the ground, the fuselage pivots around the landing gear, which has the aircraft weight and friction keeping it in place. As you come off the ground, you will need to apply left cyclic to bank ever so slightly to counter it.

Other helicopters experience this as well, but they counter it in different ways. The Mi-24 for instance has it's main transmission mounted at an angle, allowing the fuselage to remain level at a hover.

[GrEaSeLiTeNiN]

I can’t help but think all this makes it sound like the Huey and Shark have inaccurate flight characteristics, or otherwise superior flight characteristics, that make it a joy to fly. But I’d imagine the real Apache flies better than the current sim Apache for it to be safe to fly into battle.

[NeedzWD40]

2 hours ago, GrEaSeLiTeNiN said:

I can’t help but think all this makes it sound like the Huey and Shark have inaccurate flight characteristics, or otherwise superior flight characteristics, that make it a joy to fly. But I’d imagine the real Apache flies better than the current sim Apache for it to be safe to fly into battle.

The Huey and Shark being a decade into development means they've had a lot more refinements that we've yet to receive with the AH-64 at this point. Since the most recent patch was primarily bug fixes and a few SAS mods, it's not exactly there yet, though by no means is it unusable.

My experience with the recent patch has resulted in fewer SAS saturation advisories, a more aggressive collective SAS channel, and a less authoritative attitude hold. There have been no major changes that I can perceive beyond that.

[admiki]

8 hours ago, Nereid said:

The only thing that irritates me (but it did this since the AH-64D was  released), is that in a hover takeoff the bird tends to fall to the right - until it is in the air. Then any compensation for this will suddenly drift you to left. But maybe there is an explanation for this. But every day I try the AH-64D I need a little practise to get used to it.

Problem all sims have is seat-of-pants input. You can't really be pro-active if you don't know how much you need to be. We can only react to what we see. As Raptor said, it's translating tendency and you can't avoid it.

Even with Mi-24's tilted transmission, it will try to roll left on you when getting light on wheels.

7 hours ago, GrEaSeLiTeNiN said:

I can’t help but think all this makes it sound like the Huey and Shark have inaccurate flight characteristics, or otherwise superior flight characteristics, that make it a joy to fly. But I’d imagine the real Apache flies better than the current sim Apache for it to be safe to fly into battle.

DCS Huey has it's own issues with FM and Shark is specific since its counter-rotating rotors are negating a lot of issues all "normal" helicopters have.

For example, Huey also has translating tendency, but grip between skids and tires is modeled, so it just starts to slide sideways instead of rolling on you. And it's teetering rotor system, meaning fuselage will just hang suspended instead of rolling you see in Apache or Hind.

[Nereid]

11 hours ago, Raptor9 said:

You are probably seeing translating tendency. The combination of the main rotor torque and the tail rotor thrust will cause the AH-64 to translate right in a hover. Below is an image from the upcoming manual revisions, which will include better explanations of these concepts, among others.

Yes. Something like this. But in the AH-64D it seems more hard to compensate for it as in other choppers as far as I remember (and to be clear: I did not mean the countering by applying left cyclic; I meant the sudden drift to the left when airborne). But this doesn't mean it is a bad thing and it should be changed. It just that I need a few attempts to get used to it everytime (!) I try to have some fun with the Apache. And as Admiki said: We are not feeling it in a sim, so we have to rely on visuals or routine.

But currently I do like the FM on the AH-64D. On its release in EA and even several months later.... well, not so much. Either it's me or something has been improved a lot.

Edited April 15, 2023 by Nereid

[VKing]

On 4/14/2023 at 1:38 AM, Raptor9 said:

I would like to ask two open-ended questions to anyone:

1) When flying with Attitude Hold enabled (regardless of sub-mode), how many use the force trim?
2) When flying without Attitude Hold enabled, how many use the force trim?

I've been flying the Apache quite a bit again after the MT release, and I find it a blast to fly now. The collective SCAS fixes seems to have done the trick of no longer attempting to counter my altitude changes.

I always fly pressing and holding the trim release any time I'm doing basically any kind of manoeuvre, with or without hold mode enabled. Probably more than is strictly necessary, to be honest, and I tend to fly like I'm using attitude hold even when I'm not using the hold mode, especially when turning: Holding force trim and banking, trimming the aircraft in the bank and releasing force trim, then holding force trim and trimming out of the bank when I'm on the desired heading. I also frequently use hover hold and velocity hold with no issues, nor with holding hovers without the hold mode.

I've basically never experienced oscillations induced by the SCAS that I've seen others get sometimes. The weirdest flight model thing I've had is the aircraft rolling over when I've transitioned from a hover into sideways flight, but those were done under "oh-<profanity>-pop-up-SAM" circumstances, so there's a fair chance I was outside of normal acceptable parameters for the helicopter.

[pii]

15 hours ago, GrEaSeLiTeNiN said:

it sound like the Huey and Shark have inaccurate flight characteristics,

Oddly, the Huey is getting a new FM after all these years so you may be correct.

[pii]

5 hours ago, Nereid said:

well, not so much. Either it's me or something has been improved a lot.

It's you and maybe MT. After the last patch I gave it a try and, at first, thought it was better but soon after realized it wasn't. They did do some work on Hold Modes, but the FM is still sloppy. 

Oh well back to sloppy flying   

[Miro]

If a real Apache pilot says a helicopter is hard, it's hard, that's it. More practice gentlemen, unless you want ED to make a second Gazelle that can fly upside down... I like to fly Apache, I fly it a lot, and I'm getting better and better with it over time. 

Edited April 15, 2023 by Miro

[GremlinIV]

I dont think people really think it is "HARD" to fly, for me it is simply "HARD WORK" when flying, which for a modern helo with a SCAS you wouldnt expect it to be.

Actually flying the apache right now is "EASY", it just does some odd things when you dont expect it, making it a chore...

Yes you can Ying Yang around in a combat stylo, but pretend you have passengers and its bring out the sick bags...

Real pilots say things are hard to reduce competition for their job....., everybody here in DCS and that other game from MS believes they could fly in real life.... or at least want to..

Its not finished, its EA, needs work, it is WIP, etc etc, and its not fun.. IMHO

Flew the F-14 today, after patch changes,  and its real nice... so i can wait for the Apache NP

[cow_art]

12 hours ago, GremlinIV said:

I dont think people really think it is "HARD" to fly, for me it is simply "HARD WORK" when flying, which for a modern helo with a SCAS you wouldnt expect it to be.

Actually flying the apache right now is "EASY", it just does some odd things when you dont expect it, making it a chore...

Yes you can Ying Yang around in a combat stylo, but pretend you have passengers and its bring out the sick bags...

Real pilots say things are hard to reduce competition for their job....., everybody here in DCS and that other game from MS believes they could fly in real life.... or at least want to..

Its not finished, its EA, needs work, it is WIP, etc etc, and its not fun.. IMHO

Flew the F-14 today, after patch changes,  and its real nice... so i can wait for the Apache NP

So much this. It's not that it's hard. Some things are just annoying.

For example:

1.) Doing pedal turns when in position hold mode.

There are two options:

• either you just put in pedal in the direction you want to turn. But the heading hold aggressively counteracts your pedal inputs, so you need to put in a LOT of pedal to break free from heading hold. And when the heading hold finally comes off, you rotate far too violently because now the pedal input is too big for a slow,precise turn.
• or you press and hold FTR during your entire turn. That makes the heading hold go away and you can do more reasonable pedal inputs (although still really tiny ones, because the Apache yaw is insanely twitchy). But holding FTR also completely disables all other hold assists, and now you have to do a completely unassisted hover+turn.

Both of these options are extremely suboptimal. Is the Apache really meant to be this way?

2.) Retrim and SAS desaturation

The instant the FTR is clicked, the SAS starts to desaturate. As a result, all assists the SAS is giving briefly go away. This often makes the helicopter jerk when the FTR is clicked. For me this is most noticable on the yaw channel: if I try to get into a hover but my pedal position is not 100% correct, the SAS adds some yaw input. I now get in a good and stable position and click the FTR. As a result, the SAS briefly takes out the yaw correction and the helicopter nose jerks to one side. Unless I get the pedal position exactly right, this happens every time I retrim.

Yes, not a big deal but I find it extremely annoying. And I wonder if this also happens in the real Apache? Perhaps our gaming controls are too different and the real SAS logic just doesn't work well for them?  For DCS why not add a 0.1 second delay before the SAS starts do desaturate, so we can click the FTR without compromising stability?

 

(For reference in case that matters: I use a VKB Gunfighter with 200mm extension, springs removed and dry clutch. And VKB T-Rudders with springs removed and a friction mod. No curves. Apache control special options set accordingly).

 

 

Edited April 16, 2023 by cow_art

[GrEaSeLiTeNiN]

4 minutes ago, cow_art said:

1.) Doing pedal turns when in position hold mode.

There are two options:

• either you just put in pedal in the direction you want to turn. But the heading hold aggressively counteracts your pedal inputs, so you need to put in a LOT of pedal to break free from heading hold. And when the heading hold finally comes off, you rotate far too violently because now the pedal input is too big for a slow,precise turn.
• or you press and hold FTR during your entire turn. That makes the heading hold go away and you can do more reasonable pedal inputs (although still really tiny ones, because the Apache yaw is insanely twitchy). But holding FTR also completely disables all other hold assists, and now you have to do a completely unassisted hover+turn.

Both of these options are extremely suboptimal. Is the Apache really meant to be this way

I use the tap method with instant trim, helps with the rudder inputs when trying to overcome the SCAS. I would think the real Apache is safer to fly than ED's version. Otherwise, many rookie pilots would have crashed in it for sure. 

[Miro]

Watch from 0:24. The machine does not follow the hand, just like in DCS, constant delicate adjustments. There is no reason to delude yourself that after 200 or 300 hours of flight you will be a master pilot. Maybe in WT or DCS Gazelle, but I don't want such a "simulator" in DCS. A simulator is supposed to be a simulator.

[admiki]

3 hours ago, GrEaSeLiTeNiN said:

I use the tap method with instant trim, helps with the rudder inputs when trying to overcome the SCAS. I would think the real Apache is safer to fly than ED's version. Otherwise, many rookie pilots would have crashed in it for sure. 

Most if not all rookie pilots fly with instructor just for that reason until they are no longer rookie Apache pilots.

[Raven434th]

I think people are missing the point...the differences in the "handling" are VERY noticeable between pre and post patch. To the point that it's become a hazard to fly. This needs to be addressed by either fixing the flight model or telling us what settings we need to refine to compensate. If its a center of gravity thing or whatever ... we need to know exactly what been adjusted or we just end up chasing our tails.

[admiki]

OK, let's say it's CoG thing. What would you change in the way you fly?

Yes, something has changed. That's why I always go to free flight and explore. And I adapt to it.

It might take me 5 or 50 minutes to adapt. And that's it.

You are being overly dramatic.