Jump to content

Flight model and other early impressions


AcroGimp

Recommended Posts

It sure does seem to flare up with the landing flaps down on final. It caught me off guard the first time, and I actually had to do a go-around, but I landed without incident on the second try!

It's interesting that non of the RL manuals or pilot reports mention this very unusual and really dangerous pitch up tendency.

i7-7700K 4.2GHz, 16GB, GTX 1070 

Link to comment
Share on other sites

  • ED Team
It's interesting that non of the RL manuals or pilot reports mention this very unusual and really dangerous pitch up tendency.

 

The same old song... The answer is that in RL the plane is piloted "by stick force". In the sim - by position. Specialists call it "controls free" and "controls fixed". In RL as you lower flaps THREE effects are encountered:

- the plane trims at lower AoA due to nose-down moment from the flaps.

- CL increases, so even at lower AoA lift becomes higher than w/o flaps.

If the stick remains in the same position (controls fixed) the plane begins to flare loosing speed.

- increased downwash from the wing changes elevator forces, so elevator creates pulling force at the stick. As the pilot tries to maintain the same force, the stick goes forward decreasing AoA and decreasing the second effect.

Ніщо так сильно не ранить мозок, як уламки скла від розбитих рожевих окулярів

There is nothing so hurtful for the brain as splinters of broken rose-coloured spectacles.

Ничто так сильно не ранит мозг, как осколки стекла от разбитых розовых очков (С) Me

Link to comment
Share on other sites

The same old song... The answer is that in RL the plane is piloted "by stick force". In the sim - by position. Specialists call it "controls free" and "controls fixed". In RL as you lower flaps THREE effects are encountered:

- the plane trims at lower AoA due to nose-down moment from the flaps.

- CL increases, so even at lower AoA lift becomes higher than w/o flaps.

If the stick remains in the same position (controls fixed) the plane begins to flare loosing speed.

- increased downwash from the wing changes elevator forces, so elevator creates pulling force at the stick. As the pilot tries to maintain the same force, the stick goes forward decreasing AoA and decreasing the second effect.

 

I understand, and agree, of course, but I would suggest a similar implementation to that on the Spitfire Mk IX, where indeed the virtual stick deflects due to the change in trimming, and we're forced to pull it when we deflect the flaps.

Flight Simulation is the Virtual Materialization of a Dream...

Link to comment
Share on other sites

The same old song... The answer is that in RL the plane is piloted "by stick force". In the sim - by position. Specialists call it "controls free" and "controls fixed". In RL as you lower flaps THREE effects are encountered:

- the plane trims at lower AoA due to nose-down moment from the flaps.

- CL increases, so even at lower AoA lift becomes higher than w/o flaps.

If the stick remains in the same position (controls fixed) the plane begins to flare loosing speed.

- increased downwash from the wing changes elevator forces, so elevator creates pulling force at the stick. As the pilot tries to maintain the same force, the stick goes forward decreasing AoA and decreasing the second effect.

 

true. in order to overcome that, joystick should have curvature settings for multitude of speeds, say for every 15 km/h.

Link to comment
Share on other sites

  • ED Team
true. in order to overcome that, joystick should have curvature settings for multitude of speeds, say for every 15 km/h.

 

No cuvature can do it. Even FFB stick can not do it properly because of low forces.

By the way, if you have kilograms of force per 1g for the real stick the additional force due to flaps down downwash can be, say, 200-300 g abruptly applied to the stick and causing it to move. The proportional amount for the FFB joystick with 100-150 g PER 1G will be 20-30 g that is comparable with dry friction and the amount of travel causing by this force is comparable to the free play. So, quite innoticable...

Ніщо так сильно не ранить мозок, як уламки скла від розбитих рожевих окулярів

There is nothing so hurtful for the brain as splinters of broken rose-coloured spectacles.

Ничто так сильно не ранит мозг, как осколки стекла от разбитых розовых очков (С) Me

Link to comment
Share on other sites

It sadly true there is no real way to replicate it in the sim. You'd have to be feeling the real thing to get a good overall sense of what was happening. I think it's counterproductive to limit what you can do with the controls in the game in a way. I get that you would not physically be able to move the control surfices in certain situations, but artificially limiting the player with no way to communicate the forces acting on the stick is not a very good solution either.

 

I think DCS nails the flight modeling, but in my opinion the biggest downfall of sims is the inability to really feel the forces acting on the plane and the control surfices. Aircraft move around in the air a lot more than it seems to in the sim. Whether that results from a lack of modelling in the engine, or just not easily communicated when sat perfectly still in a computer chair is an entirely different question.

 

In the end though, DCS mimics the feeling of flight much better than any other sim in my opinion, based on my limited real life stock time. X-Plane 11 is getting pretty good too though.

Fire only at close range, and only when your opponent is properly in your sights.

 

-Hauptmann Oswald Boelcke, Jasta 2

Link to comment
Share on other sites

It sadly true there is no real way to replicate it in the sim. You'd have to be feeling the real thing to get a good overall sense of what was happening. I think it's counterproductive to limit what you can do with the controls in the game in a way. I get that you would not physically be able to move the control surfices in certain situations, but artificially limiting the player with no way to communicate the forces acting on the stick is not a very good solution either.

 

I think DCS nails the flight modeling, but in my opinion the biggest downfall of sims is the inability to really feel the forces acting on the plane and the control surfices. Aircraft move around in the air a lot more than it seems to in the sim. Whether that results from a lack of modelling in the engine, or just not easily communicated when sat perfectly still in a computer chair is an entirely different question.

 

In the end though, DCS mimics the feeling of flight much better than any other sim in my opinion, based on my limited real life stock time. X-Plane 11 is getting pretty good too though.

 

 

They actually found a very nice way around with the Spitfire IX...

The virtual stick deflects forward to adapt to the new trim when flaps are lowered, causing the natural pitching down moment that the pilot naturally counters by pulling the stick.

With such an approach in the Yak-52 I believe we would all be satisfied :-)


Edited by jcomm

Flight Simulation is the Virtual Materialization of a Dream...

Link to comment
Share on other sites

No cuvature can do it. Even FFB stick can not do it properly because of low forces.

By the way, if you have kilograms of force per 1g for the real stick the additional force due to flaps down downwash can be, say, 200-300 g abruptly applied to the stick and causing it to move. The proportional amount for the FFB joystick with 100-150 g PER 1G will be 20-30 g that is comparable with dry friction and the amount of travel causing by this force is comparable to the free play. So, quite innoticable...

 

I know that, I flew jet from the 60's in my air force days. What we need are long joystick rods.

Link to comment
Share on other sites

I have a joystick extended from the floor, it doesn't fix the problem. For what it's worth, I naturally adapted to the flap pitch moment with forward pressure the way I would in a real airplane. Most small airplanes have an appreciable change in pitch moment with flaps that must be anticipated and compensated for, so I really didn't find this "wrong" in any way.

 

Yo-Yo, am I correct in understanding that all calculations in the Yak are stick-fixed? Would using hinge moments help with damping at higher speeds?


Edited by aaron886
Link to comment
Share on other sites

we would all be satisfied

 

Wanna bet? ;)

 

As far as I can see, it seems this thread has degenerated into complaining that the game is a game and doesn't have the 'real' feeling of a 'real' plane. I can only say that people can get a taste of the real thing for about $25-40/hr renting gliders, or $100ish /hr renting powered aircraft. Quite affordable even if only a few hours a month ;)

Де вороги, знайдуться козаки їх перемогти.

5800x3d * 3090 * 64gb * Reverb G2

Link to comment
Share on other sites

this thread has degenerated into complaining that the game doesn't have the 'real' feeling of... the real thing for about $25-40/hr... or $100ish /hr renting powered aircraft.

 

It's $210/hr to rent an 8KCAB with an instructor. If you don't mind listening to old people talking about clouds and/or bathtubs, then the local soaring club is the most economical and fun way to fly, but there are only a handful of places where you can do glider aerobatics.

 

For a fully authentic psychosomatic experience, a gym membership and a swivel chair are necessary, to aggravate the hemorrhoids and induce motion sickness respectively. (Don't forget to hydrate.)

 

The snap/snatch is very well modeled, this is a unique characteristic of the Yak that catches new Yak pilots by surprise and it is exactly as I experience in my Yak when I ask too much.

 

The post stall/ballistic behavior is also very well modeled and matches my experience.

 

That's exciting. It will be a useful supplement to aerobatic training, once the energy retention and p-factor/torque/lateral trim issues are addressed. (High AoA modeling in Northrop-Grumman's FS2004 Special Edition™ is lacking, and nobody has 350 hours of rotary-engine Camel time to validate Rise of Flight's.)

 

Of course, I'll be refreshing the page every five minutes until you post about spins. This is the first consumer software to accurately model (aerobatic) inverted spins.

Link to comment
Share on other sites

This is the first consumer software to accurately model (aerobatic) inverted spins.

Talking about spins; Are the ailerons really so powerful that opposite aileron completely stops the spin like in the DCS Yak-52?

 

On most planes I flew, in spin aileron accelerates the spin and opposite aileron flattens the spin.

i7-7700K 4.2GHz, 16GB, GTX 1070 

Link to comment
Share on other sites

Talking about spins; Are the ailerons really so powerful that opposite aileron completely stops the spin like in the DCS Yak-52?

 

On most planes I flew, in spin aileron accelerates the spin and opposite aileron flattens the spin.

I'm not sure how applicable this is to the Yak, but I regularly fly a K-21 and anti-spin aileron will usually lead to recovery in that thing, even if it takes longer than the normal recovery procedure. At first the aircraft will bank away from the spin but then it will pitch down soon after, which leads to an increase in airspeed and therefore recovery, although often at moderate-high sideslip angles. Pro-spin aileron on the other hand will have next to no effect, maybe increasing the yaw rate slightly. I've also flown a Pilatus B4 which needs pro-spin aileron all the way through the spin, or it will recover instantly.
Link to comment
Share on other sites

  • ED Team
Talking about spins; Are the ailerons really so powerful that opposite aileron completely stops the spin like in the DCS Yak-52?

 

On most planes I flew, in spin aileron accelerates the spin and opposite aileron flattens the spin.

 

No, they are not.

The point is that this early access build does not include last changes regarding the post-stall behaviour. Rather, I should say, it's a model of early days of the Yak... So, be patient and wait for the next build.

 

Opposite ailerons flatten spin.

Ніщо так сильно не ранить мозок, як уламки скла від розбитих рожевих окулярів

There is nothing so hurtful for the brain as splinters of broken rose-coloured spectacles.

Ничто так сильно не ранит мозг, как осколки стекла от разбитых розовых очков (С) Me

Link to comment
Share on other sites

So, be patient and wait for the next build.

Opposite ailerons flatten spin.

Sounds absolutely great! Looking forward to every tiny improvement, thanx :) :)

 

@swagchimp. Gliders are completely different animals, especially when it's about spins etc...apart from the Lo100 maybe...

i7-7700K 4.2GHz, 16GB, GTX 1070 

Link to comment
Share on other sites

I have a joystick extended from the floor, it doesn't fix the problem. For what it's worth, I naturally adapted to the flap pitch moment with forward pressure the way I would in a real airplane. Most small airplanes have an appreciable change in pitch moment with flaps that must be anticipated and compensated for, so I really didn't find this "wrong" in any way.

 

Yo-Yo, am I correct in understanding that all calculations in the Yak are stick-fixed? Would using hinge moments help with damping at higher speeds?

 

forgot to add - full size handle and properly modeled command rod/wires movement would help. But there is this gray area, where only feeling the forces and the movement of the commands and general feeling of the energy state of the airplane and its behaivour would come near to real flying. Its that "flight sim realism" debate.... cheers!

Link to comment
Share on other sites

Guys... it's early access... please...

 

Of course the Yak-52 is going to have problems within the first few days to months. It isn't finished and requires a public environment to test it. Private testing can only get you so far when you have a massive community with the open beta branch who can rather report everything to you, and you check.

Link to comment
Share on other sites

Quick note on ailerons and spin behavior in the real Yak.

 

The Yak features a lot of very clever design elements - the ailerons are very powerful and remain energized and very effective deep into the stall given their slotted design and very slight offset hinge points.

 

They will NOT however take the plane out of a spin.

 

In-Spin aileron as I recall causes a slight flattening, Out-Spin aileron significantly accelerates the rate of rotation and flattens the spin as well. This is called an Aggravated Spin and I demonstrate one in a video I linked on my Advanced Spins thread.

 

And to clarify, I for one am not just complaining here, I want this module to be successful and in order for that to happen it needs to be right - especially if it is being portrayed as the result of a professional training tool development.

 

I am satisfied that the developers have more/better elements of the flight model in their internal build and am happy to wait for that to be released - but some things were so far out of sync with the real plane I felt compelled to comment on them. It seems that by and large ED is listening and taking the critique in the spirit intended (to help make it better).

 

'Gimp

[sIGPIC][/sIGPIC]

A-4E | F-5E | F-14B | F/A-18C | AV-8B NA | UH-1H | FC3 | Yak-52 | KA-50 | Mi-8 | SA-342



i7 8700K | GTX 1070 Ti | 32GB 3000 DDR4

FAA Comm'l/Instrument, FAST Formation Wingman, Yak-52 Owner/Pilot

Link to comment
Share on other sites

It sadly true there is no real way to replicate it in the sim. You'd have to be feeling the real thing to get a good overall sense of what was happening. I think it's counterproductive to limit what you can do with the controls in the game in a way. I get that you would not physically be able to move the control surfices in certain situations, but artificially limiting the player with no way to communicate the forces acting on the stick is not a very good solution either.

 

I think DCS nails the flight modeling, but in my opinion the biggest downfall of sims is the inability to really feel the forces acting on the plane and the control surfices. Aircraft move around in the air a lot more than it seems to in the sim. Whether that results from a lack of modelling in the engine, or just not easily communicated when sat perfectly still in a computer chair is an entirely different question.

 

In the end though, DCS mimics the feeling of flight much better than any other sim in my opinion, based on my limited real life stock time. X-Plane 11 is getting pretty good too though.

 

forgot to add - full size handle and properly modeled command rod/wires movement would help. But there is this gray area, where only feeling the forces and the movement of the commands and general feeling of the energy state of the airplane and its behaivour would come near to real flying. Its that "flight sim realism" debate.... cheers!

 

You could spend money on the brunner FFB joystick when the software is ready? I have spoken to these guy's and they are implementing DCS at some point, no timeline given. You can still adjust the force for now in DCS. I wish we had more options for FFB and one day we might? VKB have hinted....?

 

Brunner cls-e joystick $1.249 Euro!!

Peak Force 5Nm (5Kg at 10cm Stick length)

Travel +/- 25°

 

I'm will be considering it when the software is ready, if you think about the cost of flying IRL as a Hobby, this is a very small cost in comparison. Would be good to grab the rudder pedals too (Peak Force 200 N / 45 lbs), except there $1.749,00 Euro..!! Both for €2.868,00 and use a WH stick. mmm

 

QUOTE

"In DCS our control loading units work as USB devices with its normal functionality but no dynamic FFB. You can set a static force profile, but for now there is no FFB."

 

https://www.brunner-innovation.swiss/product/cls-e-joystick/

https://www.brunner-innovation.swiss/product/cls-e-rudder-with-toe-brakes/

 

Some more gusty turbulent elements to the weather system would be nice too.

i7-7700K OC @ 5Ghz | ASUS IX Hero MB | ASUS GTX 1080 Ti STRIX | 32GB Corsair 3000Mhz | Corsair H100i V2 Radiator | Samsung 960 EVO M.2 NVMe 500G SSD | Samsung 850 EVO 500G SSD | Corsair HX850i Platinum 850W | Oculus Rift | ASUS PG278Q 27-inch, 2560 x 1440, G-SYNC, 144Hz, 1ms | VKB Gunfighter Pro

Chuck's DCS Tutorial Library

Download PDF Tutorial guides to help get up to speed with aircraft quickly and also great for taking a good look at the aircraft available for DCS before purchasing. Link

Link to comment
Share on other sites

If I can afford a Brunner or similar expensive joystick, I'd really rent an aerobatic airplane for a few flights instead!

This super-realistic experience will last forever :)

 

Well on that front, I'm looking into hang gliding and jumping off a cliff instead.:D

Looks like heaps of fun.

i7-7700K OC @ 5Ghz | ASUS IX Hero MB | ASUS GTX 1080 Ti STRIX | 32GB Corsair 3000Mhz | Corsair H100i V2 Radiator | Samsung 960 EVO M.2 NVMe 500G SSD | Samsung 850 EVO 500G SSD | Corsair HX850i Platinum 850W | Oculus Rift | ASUS PG278Q 27-inch, 2560 x 1440, G-SYNC, 144Hz, 1ms | VKB Gunfighter Pro

Chuck's DCS Tutorial Library

Download PDF Tutorial guides to help get up to speed with aircraft quickly and also great for taking a good look at the aircraft available for DCS before purchasing. Link

Link to comment
Share on other sites

Thanks a million to AcroGimp for sharing his experience and impressions with us!

 

I'm having a blast with the Yak and I really wasn't excited about it before release. I'm now in the process of learning what I can.

 

I really hope ED will fix the few discrepancies and EA hiccups along the way. The next patch certainly makes it look like it.

 

I thought I'd share this video from AcroGimp as it's really interesting and I didn't see it on the Yak forum. Maybe I just missed it.

 

 


Edited by Bourrinopathe

/// ВКБ: GF Pro MkII+MCG Pro/GF MkII+SCG L/Black Mamba MkIII/Gladiator/T-Rudder MkII | X-55 Rhino throttle/Saitek Throttle Quadrant | OpenTrack+UTC /// ZULU +4 ///

/// "THE T3ASE": i9 9900K | 64 GB DDR4 | RTX 2080ti OC | 2 TB NVMe SSDs, 1 TB SATA SSD, 12 TB HDDs | Gigabyte DESIGNARE mobo ///

Link to comment
Share on other sites

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...