Su-27 trim issue is in need of explanation

[Yo-Yo]

Yo-Yo, please do the following experiment:

After takeoff with 56% fuel, accelerate at low level to 1000Km/h, trimming for horizontal flight. Reduce speed to 400Km/h, leaving the trim where it was. Engage full AB and pull the stick fully back and perform consecutive slow loops, maintaining the stick full aft. The AoA will oscillate around 19-21 deg, the only way to reach 24 deg AoA again is by applying trim aft. Is that behaviour correct or it is an error?

 

Do you use FFB stick?

[Fox One]

^^^ No, I use X55 stick.

[Yo-Yo]

^^^ No, I use X55 stick.

 

Doing a silly things with the system you can not hope to get smart answer from it :)

 

Do you agree that your test has nothing common with RL demands?

 

I think that this effect, if it presents, is due to using non-FFB device - you know that, for example, for helicopters FFB trim is natural and does not require any unnatural actions. THis is a discussion aging as many years of discussion as the joystick is used gor flight sims...

[Nedum]

So the point seems to be that we have a trim function which is made for FFB only?

It would be nice if we could "simulate" the same behavior for non FFB user too, wouldn't it? ;)

The center of my not FFB flight stick is always at the same point, neverless how much I have trimmed the DCS Su27 and this will give us a completely wrong feeling of a trimmed plane at different speeds.

The gamer stick input will always be wrong if he starts to trim the plane for different speeds if he isn't using a FFB flight stick.

ED should try to give us a solution to no loosing the center of control if we are using the trim function.

I don't know if this would work, but how would it be to use something like the KA50 trim function to "simulate" a real FFB flight stick for non FFB stick gamer? :dunno:

[NineLine]

So the point seems to be that we have a trim function which is made for FFB only?

It would be nice if we could "simulate" the same behavior for non FFB user too, wouldn't it? ;)

The center of my not FFB flight stick is always at the same point, neverless how much I have trimmed the DCS Su27 and this will give us a completely wrong feeling of a trimmed plane at different speeds.

The gamer stick input will always be wrong if he starts to trim the plane for different speeds if he isn't using a FFB flight stick.

ED should try to give us a solution to no loosing the center of control if we are using the trim function.

I don't know if this would work, but how would it be to use something like the KA50 trim function to "simulate" a real FFB flight stick for non FFB stick gamer? :dunno:

 

I dont have FFB and I dont have an issue with how it works now.

[Hummingbird]

I doubt ED is going to share their data, nor should they have to. They dont have to prove anything based of someones 'feelings' or 'opinion'. Show the FM that is wrong with your own data, then we will talk.

 

So what you're saying is that the data is purposely withheld so that the consumer has no chance of telling wether or not the right data is used or wether it has been interpreted right?

 

Being open about these things is a lot smarter.

[Hummingbird]

Yo-Yo, please do the following experiment:

After takeoff with 56% fuel, accelerate at low level to 1000Km/h, trimming for horizontal flight. Reduce speed to 400Km/h, leaving the trim where it was. Engage full AB and pull the stick fully back and perform consecutive slow loops, maintaining the stick full aft. The AoA will oscillate around 19-21 deg, the only way to reach 24 deg AoA again is by applying trim aft. Is that behaviour correct or it is an error?

 

^^ Point in case!

 

If one needs an FFB stick in order to avoid this then there's a problem as 90% of people don't use one.

[NineLine]

So what you're saying is that the data is purposely withheld so that the consumer has no chance of telling wether or not the right data is used or wether it has been interpreted right?

 

Being open about these things is a lot smarter.

 

Are you serious???? I mean really... serious... like not joking? Why should ED have to divulge any data they collected, most likely data they had to invest money to get, to appease one or two people that have a hunch its not right?

 

Ugh...

 

They dont need to give you anything because they promote the FM as a PFM:

 

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).

 

Bottomline, if you feel its wrong, go find the data on your own to back it up. ED gave you the PFM, thats what you paid for (actually with the Su-27, most of us didnt pay for the PFM), they arent required to give us anything more.

[Teknetinium]

I dont have FFB and I dont have an issue with how it works now.

Same, no problem whit trim rather then when going autopilot off. If you don't use FFB joystick you need to find autopilots trim setting/position on your stick in order to have smoth transition.

Edited November 3, 2015 by Teknetinium

[GGTharos]

So what you're saying is that the data is purposely withheld so that the consumer has no chance of telling wether or not the right data is used or wether it has been interpreted right?

 

Being open about these things is a lot smarter.

 

That's never the reason. The data might be confidential or otherwise proprietary. You don't have a right to them, period, end of story.

[FSKRipper]

So what you're saying is that the data is purposely withheld so that the consumer has no chance of telling wether or not the right data is used or wether it has been interpreted right?

 

Being open about these things is a lot smarter.

 

Sorry but this thread is leaving the point of justified critics. I have studied mathematics, I'm interested in aviation since 25 years and I'm a RL spare time pilot ( with only 150 hours I have to admit). Not that I would expect ED to share their information/sources with the public.

But what will qualify YOU as a consumer to judge wether the right data is used or interpreted right to comment on the FM if you are not a RL SU-27 pilot?

I admit that with all my theoretical and practical knowledge, I have no idea on how the real plane will behave until I fly it myself. You can try to compare it to other modules but what makes you believe you can give more than an educated guess about it?

 

ED delivered a solid FM to you (which is still WIP). As in all cases you are the one to bring the evidence that something isn't right here. Not by your feelings, other modules or guys that talked to some other guys but by hard FM data, statements from actual pilots and official documents.

Edited November 3, 2015 by FSKRipper

[Hummingbird]

Confidential data used in a video game accessible to any public person? Right...

[Hummingbird]

This is not about wether or not "I" am better at interpreting the data, it's about the data being freely available so that those who 100% do know how to interprete it will be able to do so.

 

In other words it's about being open about the data used, which IMO is important when a video game claims to be a simulation, and ofcourse since it is a video game none of the data used is going to be confidential to the public anyway.

 

With that having been said if the issue is that they have payed money for the information, well then simply demand money to pass on said information - some interested people will no doubt be willing to pay.

 

In short let's not twist this into anything about "rights" when it's all about being open with the basic data used as this actually promotes credibility.

 

Finally no'one is telling or demanding anyone to provide anything, I am simply saying that the smart move would be to make available the obviously non confidential data used to make the ingame FMs - most importantly as such data would douse any suspicions people might have about the FMs.

[NineLine]

Your the one that took it to the "withholding" place in this discussion, like ED somehow has to convince you they know their profession.

 

So I will go back to my original point, bring data that there is something wrong, or I will simply close this discussion as Yo-Yo has already addressed this issue. Let me know what I should do.

 

This is not about wether or not "I" am better at interpreting the data, it's about the data being freely available so that those who 100% do know how to interprete it will be able to do so.

 

In other words it's about being open about the data used, which IMO is important when a video game claims to be a simulation, and ofcourse since it is a video game none of the data used is going to be confidential to the public anyway.

 

With that having been said if the issue is that they have payed money for the information, well then simply demand money to pass on said information - some interested people will no doubt be willing to pay.

 

In short let's not twist this into anything about "rights" when it's all about being open with the basic data used as this actually promotes credibility.

 

Finally no'one is telling or demanding anyone to provide anything, I am simply saying that the smart move would be to make available the obviously non confidential data used to make the ingame FMs - most importantly as such data would douse any suspicions people might have about the FMs.

[Hummingbird]

Your the one that took it to the "withholding" place in this discussion, like ED somehow has to convince you they know their profession.

 

So I will go back to my original point, bring data that there is something wrong, or I will simply close this discussion as Yo-Yo has already addressed this issue. Let me know what I should do.

 

No that's not the point at all, I am simply asking where their information is from: i.e. if it's based on actual real life data then where can I get a hold of it if I so wished?

 

Is that really such a bad thing to ask for? Is that me attacking them? I really don't see it that way at all...

[NineLine]

No that's not the point at all, I am simply asking where their information is from: i.e. if it's based on actual real life data then where can I get a hold of it if I so wished?

 

Is that really such a bad thing to ask for? Is that me attacking them? I really don't see it that way at all...

 

This thread isnt about data collection, you should know, you started it. As such, I think this discussion is closed.