Can't hold bank angle (and pitch)

[Penshoon]

Are you trying to say that because it is more Advanced, it should handle differently than other DCS choppers in normal flight regimes?

 

I'm just saying that the handling discrepancies between Uh-1, Mi-8, Ka-50 vs Gazelle could be explained by this.

 

From https://forums.eagle.ru/showthread.php?t=122801

"Advanced Flight Model (AFM) and AFM+. An AFM uses multiple points of force application and calculation on the relevant flight surfaces. This simulates edge of envelope conditions well and avoids scripted behaviors as used in an SFM. This system also partially implements the aircraft's flight augmentation systems. DCS aircraft that use AFM includes the Su-25T. A further evolution of the AFM is what we term the AFM+ and this uses the same calculations as AFM but adds limited modeling of the hydraulic and fuel systems. Examples of AFM+ in DCS include the Su-25 and A-10A.

 

Professional Flight Model (PFM). This is generations beyond an AFM/AFM+ and is based upon:

 

• Use a wider array of wind tunnel tests CFD methods for aerodynamics parameters calculations.

• A higher level of aircraft construction details for forces calculations. For example: our landing gear model includes individual kinematics of retracting/extending is used to calculate its movement, servo-piston forces, etc. In such cases, we truly use real lengths, arms, etc. This also includes such items as a realistic simulation of airflow along the airframe due to the propeller or helicopter rotor thrust.

• Realistic simulation of Flight Control, CAS and Autopilot systems.

• Realistic simulation of Hydraulics, Fuel, Electrical, Engine and other systems influence flight characteristics.

• Unprecedented access to test data packs.

 

This is combined with much more detailed and accurate accounting of the physical forces on the aircraft and airfoils. DCS examples of the PFM include the A-10C, Ka-50, P-51D, UH-1H, Mi-8MTV2, F-15C and Su-27 (in development) for DCS Flaming Cliffs, and the Fw190-D9 (in development)."

Edited September 21, 2016 by Penshoon

[Holbeach]

Here is the Gazelle handled by somebody who knows what he is doing.

 

 

..

[BronzeYardNo11]

Here is the Gazelle handled by somebody who knows what he is doing.

 

 

..

your point is?

[Holbeach]

Description: When rolling or pitching the aircraft, there seems to be quite a bit of lag when returning the stick to center. It just keeps rolling/pitching in the direction you gave it, again despite that fact you returned to center!

 

DCS Version: 1.5.4.56500

 

Reproducible: Yes.

 

Step to Reproduce: Open the controls indicator, roll the aircraft a bit then return to center. Turn SAS off to really feel it. It happens when SAS is on too, just not as noticiable.

 

 

My earlier video, from 2.20, was in response to your OP. I rolled and pitched, but didn't get the same result as you.

If it's not reproduced correctly, just say so.

 

The 2nd one was to show a Gazelle being flown expertly, for interest sake.

 

..

[zerO_crash]

I'm just saying that the handling discrepancies between Uh-1, Mi-8, Ka-50 vs Gazelle could be explained by this.

 

From https://forums.eagle.ru/showthread.php?t=122801

"Advanced Flight Model (AFM) and AFM+. An AFM uses multiple points of force application and calculation on the relevant flight surfaces. This simulates edge of envelope conditions well and avoids scripted behaviors as used in an SFM. This system also partially implements the aircraft's flight augmentation systems. DCS aircraft that use AFM includes the Su-25T. A further evolution of the AFM is what we term the AFM+ and this uses the same calculations as AFM but adds limited modeling of the hydraulic and fuel systems. Examples of AFM+ in DCS include the Su-25 and A-10A.

 

Professional Flight Model (PFM). This is generations beyond an AFM/AFM+ and is based upon:

 

• Use a wider array of wind tunnel tests CFD methods for aerodynamics parameters calculations.

• A higher level of aircraft construction details for forces calculations. For example: our landing gear model includes individual kinematics of retracting/extending is used to calculate its movement, servo-piston forces, etc. In such cases, we truly use real lengths, arms, etc. This also includes such items as a realistic simulation of airflow along the airframe due to the propeller or helicopter rotor thrust.

• Realistic simulation of Flight Control, CAS and Autopilot systems.

• Realistic simulation of Hydraulics, Fuel, Electrical, Engine and other systems influence flight characteristics.

• Unprecedented access to test data packs.

 

This is combined with much more detailed and accurate accounting of the physical forces on the aircraft and airfoils. DCS examples of the PFM include the A-10C, Ka-50, P-51D, UH-1H, Mi-8MTV2, F-15C and Su-27 (in development) for DCS Flaming Cliffs, and the Fw190-D9 (in development)."

 

Totally irrelevant, AFM can be as good as PFM. The difference lies in whether 3rd parties use ED approved methods, or their own. So that argument is invalid. Been like this in DCS since BS2.

[Penshoon]

Totally irrelevant, AFM can be as good as PFM. The difference lies in whether 3rd parties use ED approved methods, or their own. So that argument is invalid. Been like this in DCS since BS2.

Have anything to back up that statement with? Why say that PFM is "generations beyond an AFM/AFM+" if what you say is true?

 

I believe the AFM system was developed by An.Petrocich in the flaming cliffs release era who have since then went on to be IL2/RoF flight model engineer. No other module since has been released as AFM/AFM+ so I am a bit skeptical to why they would advertise the Gazelle using that description though. I speculated that the software suit was carried over with his change of employment.

[exil]

Here is the Gazelle handled by somebody who knows what he is doing.

 

 

..

 

And now what?

 

I'm a RL Helopilot too with several flight ours on several models. And i would say, the one i have flown which comes closest to the Gazelle is the EC-120B. Three-bladed rotorsystem, fenestron, etc. But i still think the FM is a bit buggy. What doesn't mean, that the FM is generally crap.

The main reason complaining (just a bit) about the FM is the fact, that you're not able to turn and maintain speed or altitude with a level flight power setting. I encounter this behaviour IRL too, but with a much greater bankangle.

 

It was no problem to maintain altitude with none of the helo's i've flown with an bank angle of about 20°.

 

What also is a bit strange is that you need pedal input to perform a coordinated turn regardless of the wind situation (even with 0 wind velocity), the bank angle and without any changes of power settings.

 

If you keep an eye on those particularities, the gazelle is one of the best (if not the best) helo to fly in DCS. But if you ask me if it feels real, i would say: no and yes!

 

No, because of the points i made in the lines above.

Yes, because the FM has some real advantages compared to other helo's in DCS. For example what some people call twitchyness. Making tiny inputs on cyclic feels really real. Or straight and level flight: Some people complained about the gazelle running like a train. But (with no gust and a laminar wind) this is basically what a helo does when trimmed out and no changes of power settings occur.

[BronzeYardNo11]

I rolled and pitched, but didn't get the same result as you.

 

Yeah, but you had SAS on, I'm talking about when it's off.

[Holbeach]

Yeah, but you had SAS on, I'm talking about when it's off.

 

I also did it with SAS off and also during turns. Apart from a sightly longer time to settle down, the result was the same.

 

..

[BronzeYardNo11]

I also did it with SAS off and also during turns. Apart from a sightly longer time to settle down, the result was the same.

 

:huh: So why am I getting odd behaviors and not you?

 

'tis very very strange

[zerO_crash]

Have anything to back up that statement with? Why say that PFM is "generations beyond an AFM/AFM+" if what you say is true?

 

I believe the AFM system was developed by An.Petrocich in the flaming cliffs release era who have since then went on to be IL2/RoF flight model engineer. No other module since has been released as AFM/AFM+ so I am a bit skeptical to why they would advertise the Gazelle using that description though. I speculated that the software suit was carried over with his change of employment.

 

Yes, it has been discussed in a thread with devs, not going to bother to find it as I cannot even remember where it was. And the "PFM is generations beyond" refers to the default AFM, ED one. ED PFM =/= ED AFM, simple.

 

Also, what are you talking about?! Mig21Bis is Leathernecks AFM (is really PFM). Mirage 2000C is also using AFM (although it`s not going to be quite on top as PFM afaik they didn`t use wind tunnel testing, rather hard data from reliable sources).

 

They are advertising it that way because Polychop has developed their own engine for aerodynamic caluclation (Please correct me Poly if I made a mistake here), meaning they use their own method, not specified ED one for achieving the highest level of simulation.

 

Also, I don`t "speculate" or "think", I write what I know. I have no interest in providing misinformation, esp. with so many new people around not being familiar with how this all started and how it`s working.

[Holbeach]

And now what?

 

 

The guy in the vid has nailed the in game Gazelle, whether it be a good FM or not.

 

Rather than answer your points in detail, I will say this.

With a Saitek and no pedals, it has for me, become much more pleasant to fly.

It use to be twitchy,and landing was difficult, as here.

 

but not any longer, since the FM has been updated.

 

But it has some serious flaws.

 

I can take off, collective only, in a stable, anti clock, rotation, climb to any altitude without further input, then drop the collective to zero, drop straight down and land, without any other control input, but the collective.

Or, T/O and climb out, go and make a cup of tea, without any input and it will still be on the same heading and climb, when I get back, yank the collective up and down, but it will make no difference, it will stay on the same heading.

 

The Huey is the best Chopper. :)

 

..

Edited September 22, 2016 by Holbeach

[exil]

The guy in the vid has nailed the in game Gazelle, whether it be a good FM or not.

 

Rather than answer your points in detail, I will say this.

With a Saitek and no pedals, it has for me, become much more pleasant to fly.

It use to be twitchy,and landing was difficult, as here.

 

but not any longer, since the FM has been updated.

 

But it has some serious flaws.

 

I can take off, collective only, in a stable, anti clock, rotation, climb to any altitude without further input, then drop the collective to zero, drop straight down and land, without any other control input, but the collective.

Or, T/O and climb out, go and make a cup of tea, without any input and it will still be on the same heading and climb, when I get back, yank the collective up and down, but it will make no difference, it will stay on the same heading.

 

The Huey is the best Chopper. :)

 

..

 

I know what you mean, but this time i guesstimate it's the SAS supporting a sort of "heading hold" feature. For example the CH-53 does the exact same thing (as long as you don't move the collective harshly). It holds heading even with collective inputs during hover. Basically no pedals needed. But i'm with you, you would at least need cyclic movements during hover. Woulnd't be possible to hover or T/O without cyclic input.

 

And yes, the Huey is also fantanstic! I still love it, after so many years eventhough it has also a few bugs in the FM (and this is not my exclusive opinion, but also from some RL huey drivers i know also playing DCS). For example, dropping or raising the collective leads to to excessive pitch down/up behaviour.

 

So both choppers have their difficulties, but once you get used to it, both are beautiful aircrafts ;)

[Penshoon]

Yes, it has been discussed in a thread with devs, not going to bother to find it as I cannot even remember where it was. And the "PFM is generations beyond" refers to the default AFM, ED one. ED PFM =/= ED AFM, simple.

 

Also, what are you talking about?! Mig21Bis is Leathernecks AFM (is really PFM). Mirage 2000C is also using AFM (although it`s not going to be quite on top as PFM afaik they didn`t use wind tunnel testing, rather hard data from reliable sources).

 

They are advertising it that way because Polychop has developed their own engine for aerodynamic caluclation (Please correct me Poly if I made a mistake here), meaning they use their own method, not specified ED one for achieving the highest level of simulation.

 

Also, I don`t "speculate" or "think", I write what I know. I have no interest in providing misinformation, esp. with so many new people around not being familiar with how this all started and how it`s working.

Think you are mixing up AFM with EFM, see https://forums.eagle.ru/showthread.php?t=122801

Guess it simply could be a misprint in the product page naming it AFM instead of EFM. Take what you will from it, I'm not here to argue. :pilotfly:

Edited September 21, 2016 by Penshoon

[zerO_crash]

Think you are mixing up AFM with EFM, see https://forums.eagle.ru/showthread.php?t=122801

Guess it simply could be a misprint in the product page naming it AFM instead of EFM. Take what you will from it, I'm not here to argue. :pilotfly:

 

Well, put it simply, EFM can be on any level, it`s really a term used in conjunction with the others, unless EFM is on PFM level, if the EFM was on AFM level (again, comparing to ED`s level system SFM-AFM-PFM), it would be mentioned as such I suppose. EFM is really a newer term, and wasn`t used in the beginning as far as I remember when 3rd parties started emerging. I also do remember the initial Mig21Bis being advertised as the LN`s AFM being equal to ED PFM standards. I guess I should correct myself that it´s called EFM now. But overall, it`s not so important what they call it, more important what they simulate. Technically, the only difference being that PFM undergoes more windtunnel tests as opposed to computer calculations based on formulas (and tuned to real life data) - again, you just cannot notice the difference here, because even "if" calculation part would be off, it would be tuned to the RL data (not that I`ve encountered any FM being off - don`t count the beta`s)

 

As for Gazelle being still advertised as AFM, well, I guess devs could mention what`s up here, but I wouldn`t really bother with these simulation levels (unless it is SFM) as you simply cannot notice the difference between AFM (+ or not) and PFM (again, EFM covers these). I would doubt that even a real pilot would not notice a difference here, as the difference is smaller than say weight (light vs heavy) factor, wind, etc... (the last statement is based on some pilot Q/A for A10`s, F15`s, Mig21`s, Mi8`s etc...)

[LazerPotatoe]

I don't know why people keep talking about difficulty. We are not complaining that it is too difficult -- just that it doesn't seem to match any other helicopter flight dynamic.

 

When I hold a small amount of left cyclic, it wants to roll me upside down. But when I use the magnetic hold in the same position, it does a graceful turn. Maybe I'm missing something here?

[Holbeach]

I know what you mean, but this time i guesstimate it's the SAS supporting a sort of "heading hold" feature. For example the CH-53 does the exact same thing (as long as you don't move the collective harshly). It holds heading even with collective inputs during hover. Basically no pedals needed. But i'm with you, you would at least need cyclic movements during hover. Woulnd't be possible to hover or T/O without cyclic input.

 

Unfortunately, it does exactly the same heading hold, T/O and landing, with the pilot off. It's simply not possible to yank the collective up and down and with no pedal or cyclic input, stay on the same heading or T/O and land.

 

Can a real helicopter do this?

 

Well no, of course it can't. Stable rotation with flat vertical descent, (4000 fpm) to land, (no pedal or cyclic input) and course maintained with full collective movement, plus landing, both without cyclic, pedal, or trim input. This FM needs a bit more looking at. SAS is turned off. No helicopter on Earth can do this stuff.

 

 

..

Edited September 24, 2016 by Holbeach

[msalama]

in whether 3rd parties use ED approved methods, or their own

 

No. If they're aiming for a PFM-level flight model but use their own methods instead of ED's, it's called EFM. I suggest you read the following, it's all explained there:

 

https://forums.eagle.ru/showthread.php?t=122801

 

So as stated by Wags, PFM is indeed more accurate than AFM/AFM+.

[zerO_crash]

No. If they're aiming for a PFM-level flight model but use their own methods instead of ED's, it's called EFM. I suggest you read the following, it's all explained there:

 

https://forums.eagle.ru/showthread.php?t=122801

 

So as stated by Wags, PFM is indeed more accurate than AFM/AFM+.

 

a) PFM is more accurate than AFM, never argued with that. You should re-read what I wrote. For all you know, it could be at PFM level, or closer to AFM. Simple.

 

b) If you read closely, the definition of EFM in it being a 3rd party approach at PFM level, but HOW FAR away or how close they are, is another thing. And that is what I point out!

[msalama]

PFM is more accurate than AFM, never argued with that.

 

And yet you said:

 

Totally irrelevant, AFM can be as good as PFM.

 

So I don't know about you, but IMHO, that which is more accurate is also better. Or did you mean to compare a shoddily made PFM with a brilliant AFM perhaps?

 

Anyway, I'm out. Got more urgent things to do than splitting hairs here ;)

[zerO_crash]

And yet you said:

 

 

 

So I don't know about you, but IMHO, that which is more accurate is also better. Or did you mean to compare a shoddily made PFM with a brilliant AFM perhaps?

 

Anyway, I'm out. Got more urgent things to do than splitting hairs here ;)

 

Well pardon that, should have said close to. Was thinking more of the older days where EFM wasn`t really used much, instead they would call it AFM, such as Mig21, before updating that info. I can see how that was confusing...

 

Well anyways, as you say, kinda irrelevant. What`s important to point out is that gazelle is very well made, and high accurate (judging here from videos + research)

[exil]

Unfortunately, it does exactly the same heading hold, T/O and landing, with the pilot off. It's simply not possible to yank the collective up and down and with no pedal or cyclic input, stay on the same heading or T/O and land.

 

Video showing, "stone drop" descent to land and "on rails" stable handling without cyclic or pedal input.

 

 

..

 

Yep, got your point! Doesn't seem to be realistic...

 

But that really doesn't bother me much. What is really important for me (really just my personal opinion), is that you can't turn without that strange behaviour.

[Whisper]

Well pardon that, should have said close to. Was thinking more of the older days where EFM wasn`t really used much, instead they would call it AFM, such as Mig21, before updating that info. I can see how that was confusing...

 

Well anyways, as you say, kinda irrelevant. What`s important to point out is that gazelle is very well made, and high accurate (judging here from videos + research)

 

And that's where Penshoon original post makes sense : if Polychop indeed use AFM as advertised, and no method of their own (making it an EFM), then they are limited to a set of parameters for their FM. AFAIK no other chopper in DCS uses AFM.

Actually, looking into it, no other chopper even use EFM, unless Polychop doesn't use AFM as advertised but internal tools to build an EFM.

ED (obviously) and BST (if I'm not mistaken they have access to tools other third party do not, thus use PFM) use PFM for their chopper. AFM may have limitations for choppers that do not allow certain features for Polychop.

[zerO_crash]

And that's where Penshoon original post makes sense : if Polychop indeed use AFM as advertised, and no method of their own (making it an EFM), then they are limited to a set of parameters for their FM. AFAIK no other chopper in DCS uses AFM.

Actually, looking into it, no other chopper even use EFM, unless Polychop doesn't use AFM as advertised but internal tools to build an EFM.

ED (obviously) and BST (if I'm not mistaken they have access to tools other third party do not, thus use PFM) use PFM for their chopper. AFM may have limitations for choppers that do not allow certain features for Polychop.

 

No other chopper uses less than PFM because they are made by ED and Belsimtek (ED partner, consider them complete insiders of ED). Again, I wouldn`t go into the naming too much as there have been mistakes made here before with advertising by devs where it was corrected afterwords. The case being, Polychop`s model resembles the real gazelle so closely that it`s accepted by pilots and Airbus. (I`m sure they will improve on the aspects of flight envelope that are not mapped -> read not flown by real pilots.)

[Whisper]

No other chopper uses less than PFM because they are made by ED and Belsimtek (ED partner, consider them complete insiders of ED). Again, I wouldn`t go into the naming too much as there have been mistakes made here before with advertising by devs where it was corrected afterwords. The case being, Polychop`s model resembles the real gazelle so closely that it`s accepted by pilots and Airbus. (I`m sure they will improve on the aspects of flight envelope that are not mapped -> read not flown by real pilots.)

 

I'm not saying the Gaz' FM is bad or only up to AFM standard. Just that Polychop stated that they had the FM nailed... well, I don't remember the exact terms, but it was along the line "to the best of our possibilities". Perhaps not having access to PFM model and only using their own tool to extend from AFM into what we have here prevent them to simulated everything, and that could explain the discrepencies seen between the Gaz' and the other choppers.

 

Yes, that's reading really much into words, I agree :) It's just that there may be more into some of the FM issues than just Poly being stubborn, happy with it , etc... They may be hitting a limitation.