What does 'SAS Saturated' mean?

[gatordev]

On 8/2/2022 at 8:32 AM, TZeer said:

You can still get this in normal flight. If you trim you aircraft (Force Trim Release), and operate the Apache in a way that makes the SCAS reach it's limits, you will saturate the SCAS.

Let's say you trim your Apache to fly straight. Let's say you are doing 90 knots. The SCAS is then trimmed at that spot and will assist you. Yaws, stick etc.

Now you want to decrease speed. As you loose speed, you will need to increase input on your Yaw. If you don't, the SCAS will do it for you, until the 10% limit is reached, and it's saturated.

The question I haven't heard answered is why do I, as the pilot, care if it's saturated?  Or to ask the question more precisely, why does saturation require both a light and a tone?  The helicopters I've flown in the real world with SAS only gives a warning if it degrades/fails (or is turned off), so I'm curious to hear from the Apache guys here if they know why Boeing thought saturation was such an urgent matter.

 

[mbits]

I think it's because it can no longer keep you stable in a fixed position.

It feels like it happens far too much right now though and holding force trim up doesn't seem to stop it for long.

[Floyd1212]

Well, for one thing, if the Collective channel becomes saturated (as it often does) it may mean that the SAS can no longer keep the helo from falling out of the sky.  This is useful when you have your head buried in the F10 map, but I'm sure it is unlikely a real Apache pilot would be in that situation.

[GrEaSeLiTeNiN]

 

[Hiob]

I flew the AH-64 yesterday for the first time in a while. The behavior of the Collective SAS is definitely weird. And new. I wasn't even aware that the Collective is SAS augmented in the past. 

[mbits]

2 hours ago, Hiob said:

I flew the AH-64 yesterday for the first time in a while. The behavior of the Collective SAS is definitely weird. And new. I wasn't even aware that the Collective is SAS augmented in the past. 

Same here. Hadn't been on it for a good while and pulled up the controller info panel to see the green collective line and thought "oh was that a thing last I flew?".  I feel so much better just hearing schoolio64d say its not normal and that he barely heard the sas saturation tone in 6 years! Thats all I wanted to know...am I doing something wrong or is this just not right at the moment in the beta? Now I know.

Edited September 15, 2022 by mbits

[gatordev]

On 9/11/2022 at 3:42 PM, Floyd1212 said:

Well, for one thing, if the Collective channel becomes saturated (as it often does) it may mean that the SAS can no longer keep the helo from falling out of the sky.  This is useful when you have your head buried in the F10 map, but I'm sure it is unlikely a real Apache pilot would be in that situation.

Unless the Apache has a drastically different system, SAS is an inner-loop system and doesn't prevent flight deviations, it only dampens inputs to a flight control (ie, rotor in a helicopter) system.  Some sort of outer-loop system would be needed to prevent you from falling out of the sky.  Typically this is in the form of an autopilot and/or trim system.

Given the other thread with the video posted, it sounds like seeing the caution light isn't actually a normal occurrence in the real thing, which makes more sense.

[jubuttib]

The collective SAS is indeed binging at me constantly, seemingly with any slight change in altitude or ascent/descent rate. It's gotten to the point that I turn off the collective channel of the SAS altogether.

[mbits]

Another real pilot talks about it here, along with his views on the flight model in general.

[Raptor9]

7 minutes ago, mbits said:

Another real pilot talks about it here, along with his views on the flight model in general.

I read this article today as well, and this is my response because I know it will probably snowball:

1) This is one AH-64 pilot's impression of the DCS AH-64D. Multiple real pilots that have just as much experience flying it have (at great length) provided feedback on recommended improvements to the flight model and SCAS characteristics of the DCS AH-64D. Anyone that has been around this forum section for longer than two weeks has seen myself or one of the other SME's openly state that there are inaccuracies with the flight model that are actively being addressed by the dev team. This isn't some big revelation. But hardware does play a big role in simulation, so his own assessment is no less subjective than any other pilot's.

2) From what I gathered reading the article, the author did not seem to understand that the aircraft is in fact representative of a very specific avionics version and era, as stated in the FAQ section on the forums as well as the manual. His statement that the aircraft represents multiple aircraft versions across 15 years is 99.9% false (There is a discrepancy in the shape of the underside of the engine nacelles, but that is a known item). Beyond that, there are no known inaccuracies based on the configuration that is modeled. He does not identify any of these inaccuracies that he is referring to, which makes it impossible to judge what his assessment is based on. Further, he makes references to "equipment timelines" that were misunderstood or unknown. Again, without him identifying what he is referring to, the statement itself is probably not within the proper context. For example, there is no BFT antenna installed because this system is not planned for implementation due to sensitivity reasons.

3) In one instance, he admits that he doesn't know what systems are fully modeled and which ones are actually "inaccurately implemented". As an example, he mentions that the ice detector is cycling to random values, yet the stickied posts in this section list the anti-icing systems as "later in Early Access". But then he subsequently makes a series of very generic assessments on such systems, after admitting he isn't sure which version of the AH-64D is being modeled, although he does say it seems to be based on an older version of the software. Without knowing what version is being modeled (which, again, is listed here and in the manual), how can he assess the accuracy of the avionics? If he is incorrectly assessing that this aircraft is a mash-up of many AH-64D versions (which it is not), than I can see how he may incorrectly see inaccuracies if he is expecting something different than what the DCS: AH-64D is modeled after. Elsewhere, he makes very generic statements about the pages. I get that he may not be going into detail due to sensitivity concerns, which I respect and support. But in doing so, it makes the credence of his assessment on the accuracy of the module in question if it is driven by generic statements and not quantifiable data.

And before it happens, I want to stress this does not mean that it is ok to post real-world documentation on here to credit or disprove his assessments, nor mine. The reason I am posting this here is to bring awareness to the fact that his review is based on a broad misunderstanding of what the DCS: AH-64D is, or what it is not. There are additional things that I feel are questionable in the review, but these three items are the big ones.

The author is very direct and honest with his review, so I will be equally direct and honest with what I am about to say:
I suspect many people reading this post will probably interpret it as an ED team member that is speaking on behalf of Eagle Dynamics and their interests. I can assure you, this is not the case. I joined the ED team this summer because I wanted to contribute to DCS. This drive comes from the perspective of a player and as someone that is passionate about aerospace and bringing such experiences to those that might never have the opportunity to fly themselves. If anyone has read my posts in the past you know that I will be brutally honest about what is accurately modeled versus what needs improvement/refinement (short of restricted documentation/information or what is not appropriate for discussion of course). If I don't know something as fact, I will simply say I don't know or identify my statement as an opinion or as a "reasonable certainty". Overall, I get the impression the author did not not do his homework prior to writing a review, based on his own misunderstandings of the DCS: AH-64D. Therefore a lot of the content within that article should be taken with a grain of salt from the lack of specific context that was not provided.

[mbits]

Thanks for the response. To be honest as a casual simmer the only thing which concerns me is his personal experience of it being really hard to fly compared to real life inspite of trying different controller settings. He is using one hell of an expensive and uncommon setup though.

He comments on how tippy/rolling it is and the constant sas which isn't accurate.  Views also recently shared by another real pilot on youtube as mentioned in this thread.  I just wish it was a bit easier to fly   Maybe that will come in time.

Edited September 21, 2022 by mbits

[cow_art]

8 hours ago, Raptor9 said:

 Multiple real pilots that have just as much experience flying it have (at great length) provided feedback on recommended improvements to the flight model and SCAS characteristics of the DCS AH-64D. Anyone that has been around this forum section for longer than two weeks has seen myself or one of the other SME's openly state that there are inaccuracies with the flight model that are actively being addressed by the dev team.

As a software developer myself I can definitely feel your pain on this. The people who carefully read all your responses definitely know that by now. Everyone else probably not so much.

Perhaps it would be a good idea to sticky a "Yes, the flight model is still unfinished. We know. We are working on it."  post in the forum and provide a summary of all the improvements the SMEs suggested to the devs?

[mbits]

I'm not bothered if a work in progress helicopter has issues.  I think almost everyone here knows its not finished.

Personally I feel there could be better, more detailed comms of what devs are doing though. For it to be an "open beta" which implies open beta "testers".  I just don't enjoy flying/testing it when the response is often "works fine here" or a one liner days/weeks later in the patch notes related to the issues being reported. That's my choice though, I don't have to fly it. No worries.

[GrEaSeLiTeNiN]

On 9/21/2022 at 8:00 PM, cow_art said:

Perhaps it would be a good idea to sticky a "Yes, the flight model is still unfinished. We know. We are working on it."  post in the forum and provide a summary of all the improvements the SMEs suggested to the devs?

+1 

We get that the FM and SAS are being worked on. But I'm curious if they are being fixed behind the scenes and then released in the recent updates because I don't see FM/SAS mentioned in the changelog (perhaps I missed it). I'd understand too if they do not want to mention it if the changes are still fluid or experimental, unless there is something major worth mentioning.  

[exil]

I think he may have a certain point regarding different flight control setups.

I am a DCS Simmer since the Huey went to life and also a RL pilot. I've had multiple setup of joysticks over the years of simming. Currently I have a 40cm gooseneck extension on my Warthog (in fact, a bit too long already). Since that upgrade every helicopter in DCS or MSFS or X-Plane feels more natural than ever before to me compared to my real life experience. Even the Apache feels pretty good to me (leaving out the know flaws). I, personally have no problems hovering the aircraft while other users report that it's barely possible in the current state. 

I experienced this also on another occasion. With this setup I did a huge amount of FM tweaking for a MSFS third party company. While with my setup the helicopter felt pretty good and close to the real deal, a lot of people with shorter sticks were complaining about the twitchiness. 

So, in short you can tweak certain parameters of a FM just after numbers out of the manual or with the help of recorded data during flight. Things like at weight X with powersetting Y it should climb xx ft/min at a certain speed. 

But you can't really tweak a feeling of a FM as long as you don't have the exact controls of the aircraft you are modeling. So it's highly dependent on your setup. Alone the length of the stick has so much influence on the feeling. 

So what's the conclusion for it? Well, you can go two ways here. You can of course build a home cockpit. Or you need to be aware of the fact, that there is no unique representation of a FM as long as we don't use the same setup. 

I also noticed another thing. A lot of companies (not specifically ED) have SMEs that have a lot of experience with their aircraft but have 0 experience in simming.

Bu this is also so important. A lot of my older buddies are used to real life simulators which in fact have a <profanity>ty representation of a FM. Guess what, they would applaud to every FM that's a tiny bit better than their real world sim experience. But it still might not be a good FM for current state of the art in DCS. What happens now is, they are telling their devs that their FM is great while it's actually not. And devs believe them because they are SMEs. 

So we basically need devs who are able to translate a FM into code and good SMEs that are also simmers and know how to translate their feeling into the sim. So I am pretty happy we have someone like @Raptor9 on the Apache who can provide that. I really believe this is a crucial point for a good model. And the devs of ED are highly capable of building excellent helicopters. So all in all, I belive the apache will shine bright in the future. 

[Raptor9]

@bradmick is also a major flight sim player as well, and is a wizard at rotorcraft aerodynamics.

I've been playing flight sims since the late 80's (5.25" floppy disks), and have also experienced precisely what you are saying regarding the differences between a real aircraft and it's professional simulator counterpart. Raw numbers aren't the whole story when it comes to simulation. Even the background sounds can make a difference in replicating how the aircraft feels in flight.

Multi-sensory perception is important, so when you take away the "seat-of-the-pants" feeling (proprioceptive inputs, for you nerds), there is often a need to supplement the remainder of sensory inputs with something else. And what that solution ends up being can be a hard nut to crack, and may be different for any given simulator or game depending on the "feel" of it all.

[Hiob]

46 minutes ago, Raptor9 said:

Multi-sensory perception is important, so when you take away the "seat-of-the-pants" feeling (proprioceptive inputs, for you nerds), there is often a need to supplement the remainder of sensory inputs with something else. 

A little bit off topic, but that is precisely the reason why I wished ED would make more use of some „exaggerated“ sounds even if they would not necessarily be audible to the real pilot in the real aircraft - like alpha, airbrakes, burner or the click of the throttle detent. Personally I think, that sound is probably the best substitute for haptic feedback there is.

On topic: A long extension for the stick (in combination with a very light spring) is really a game changer for DCS Helicopters. I second this. However, comparing the flight model of different choppers inside DCS with the very same controls setup, sometimes makes them feel a little bit out of order, especially regarding things like „inertia“ and „twitchyness“. Where (in my humble and unqualified) opinion, the Huey, Hip and Hind feel more or less plausible to each other (and overall good), the Gazelle is a RC-Helicopter with no weight at all and the Apache is a bit „inconsistent“ atm. Which is perhaps due to its augmentation systems. A matter of fine tuning probably.

[bradmick]

1 hour ago, Raptor9 said:

@bradmick is also a major flight sim player as well, and is a wizard at rotorcraft aerodynamics.

I've been playing flight sims since the late 80's (5.25" floppy disks), and have also experienced precisely what you are saying regarding the differences between a real aircraft and it's professional simulator counterpart. Raw numbers aren't the whole story when it comes to simulation. Even the background sounds can make a difference in replicating how the aircraft feels in flight.

Multi-sensory perception is important, so when you take away the "seat-of-the-pants" feeling (proprioceptive inputs, for you nerds), there is often a need to supplement the remainder of sensory inputs with something else. And what that solution ends up being can be a hard nut to crack, and may be different for any given simulator or game depending on the "feel" of it all.

I’ve been simming since around 1991 when we got our first computer. It’s been Flight sim, Longbow 1&2, Falcon 3, Comanche, ARMA, Operation Flashpoint, Janes WW2 fighters, Enemy Engaged, Gunship, X-plane, IL2 and all of its subsequent releases to date, Ruse if Flight, you name, I’ve probably flown/played it. Those are the biggies that come to mind.

I’m a nerd.

[Dragon1-1]

I think that a stick extension is definitely not too much to ask for, as far as helo drivers are concerned. I'm fine with it feeling twitchy on a short throw sidestick, I managed to cope with other helos. I'm looking forward to the FM, and particularly the FMC, being improved.

[Swift.]

9 hours ago, Hiob said:

A little bit off topic, but that is precisely the reason why I wished ED would make more use of some „exaggerated“ sounds even if they would not necessarily be audible to the real pilot in the real aircraft - like alpha, airbrakes, burner or the click of the throttle detent. Personally I think, that sound is probably the best substitute for haptic feedback there is.

On topic: A long extension for the stick (in combination with a very light spring) is really a game changer for DCS Helicopters. I second this. However, comparing the flight model of different choppers inside DCS with the very same controls setup, sometimes makes them feel a little bit out of order, especially regarding things like „inertia“ and „twitchyness“. Where (in my humble and unqualified) opinion, the Huey, Hip and Hind feel more or less plausible to each other (and overall good), the Gazelle is a RC-Helicopter with no weight at all and the Apache is a bit „inconsistent“ atm. Which is perhaps due to its augmentation systems. A matter of fine tuning probably.

I'd like to say that I wholeheartedly disagree. The ridiculously loud switches in something like tomcat completely ruin the experience for me. Like in what universe is the faint click of the radalt needle hitting the lower stop post going to be louder than the engines!

[Hiob]

1 hour ago, Swift. said:

I'd like to say that I wholeheartedly disagree. The ridiculously loud switches in something like tomcat completely ruin the experience for me. Like in what universe is the faint click of the radalt needle hitting the lower stop post going to be louder than the engines!

I think you missed my point, but nevertheless, you are entitled to disagree of course.

Edit: the cherry on top would be, if they made the volume control even more granular and give us separate control over those effects.

Edited September 27, 2022 by Hiob

[Dagobert666]

1 hour ago, Swift. said:

I'd like to say that I wholeheartedly disagree. The ridiculously loud switches in something like tomcat completely ruin the experience for me. Like in what universe is the faint click of the radalt needle hitting the lower stop post going to be louder than the engines!

 

1 hour ago, Hiob said:

I think you missed my point, but nevertheless, you are entitled to disagree of course.

I absolutely agree with Hiob.
At home in front of a computer screen, we lacked important sensory feedback that a real pilot has. In Germany we call this the "popometer". Translated, that means something like "Buttocks-Display". You just feel what the machine is doing... The vibration, the pressure, the changes in direction of movement. Since we don't have that in a sim we need a spare and the F14 module is great at simulating that. You can hear the AoE, you can hear the stall coming, you can hear the airframe overloading. And Jester also helps a lot by announcing speeds etc. I wish all of this for the AH64 and George as well.

Edited September 27, 2022 by Dagobert666

[Swift.]

35 minutes ago, Dagobert666 said:

 

I absolutely agree with Hiob.
At home in front of a computer screen, we lacked important sensory feedback that a real pilot has. In Germany we call this the "popometer". Translated, that means something like "Buttocks-Display". You just feel what the machine is doing... The vibration, the pressure, the changes in direction of movement. Since we don't have that in a sim we need a spare and the F14 module is great at simulating that. You can hear the AoE, you can hear the stall coming, you can hear the airframe overloading. And Jester also helps a lot by announcing speeds etc. I wish all of this for the AH64 and George as well.

 

Buffet is one thing, having a switch with a 200db action is another...

 

Feedback on Airframe performance exists in many modules, including Apache. Think about how you can hear the rotor speed, you can tell what the blade AOA based on the noise the rotor makes. Etc.

What isn't seen other than tomcat is the 'tactile' switches as you put it. Something that is completely ridiculous to anyone using an actual switch instead of button jabbing with the mouse.

[Hiob]

Guys, we digress from the topic of this thread. I'd say, we cancel discussion about sound effects here. Ok?

(Yes, I'm aware, that I started this. Sorry!!!)

Edited September 27, 2022 by Hiob

[Dagobert666]

8 minutes ago, Swift. said:

Buffet is one thing, having a switch with a 200db action is another...

 

Feedback on Airframe performance exists in many modules, including Apache. Think about how you can hear the rotor speed, you can tell what the blade AOA based on the noise the rotor makes. Etc.

What isn't seen other than tomcat is the 'tactile' switches as you put it. Something that is completely ridiculous to anyone using an actual switch instead of button jabbing with the mouse.

Swifty, I think the problem is that you're talking about loud buttons and we're talking about sound feedback in general.
The volume of the button presses is a single small detail. That has nothing to do with the feedback the plane gives you.

-Yes, they are too loud for you ok.
-And I can follow the argument you bring too. So, buttons that are louder than the afterburner. Personally, this one detail doesn't bother me. But YES YOU ARE RIGHT they are unrealistically loud.
-Although I have to admit I've never been in a real F14 so I don't know how loud these buttons really are compared to the afterburner which is outside the cockpit and further away at the end of the plane and the sound has to be upwind and come through the cockpit insulation.

Swifty it was never about the buttons. It was about the sound feedback when flying.