Su-27 controls in DCS vs RL

[rami80]

I was watching this video

where a pilot performs a cobra. He first pulls the stick and then when maximum aoa is reached he forces it down all the way until the nose starts going down and then pulls the stick slightly backwards. When attempting this in DCS the plane's nose falls to rapidly. Should this be reported as a bug? It feels like one of the reasons the aircraft has troubles pointing its nose in game.

[Ironhand]

No, it seems to take the same 3 or 4 seconds for the nose to come down:

 

It might have something to do with the airspeed at which the maneuver is initiated, too. I haven't paid too much attention to the time it takes at various airspeeds.

 

Nice link by the way. It shows what's happening in the cockpit well.

[rami80]

No, it seems to take the same 3 or 4 seconds for the nose to come down:

 

It might have something to do with the airspeed at which the maneuver is initiated, too. I haven't paid too much attention to the time it takes at various airspeeds.

 

Nice link by the way. It shows what's happening in the cockpit well.

 

This isn't exactly what I was pointing at. If the stick is pushed forward as in the video, after the nose levels it will continue moving downward.

 

Glad you like it :D

[Ironhand]

This isn't exactly what I was pointing at. If the stick is pushed forward as in the video, after the nose levels it will continue moving downward...

And what you see starting, just as that clip ends, is the quick, snap of the stick back to stop the downward movement. :)

[tovivan]

Nice link by the way. It shows what's happening in the cockpit well.

 

You don't know the Wings of Russia Studios docus? :O

 

They've made docus about most Soviet/Russian planes, even detailed docus about MiG-25/31, Su-27, MiG-29, Tu-160, Mi-8 and Mi-24. Fantastic watching. In the general series about the planes (sorted on type of planes) the narrator is a bit hard on the ears, but he actually grew on me quickly and I like hearing him now. :D

 

They're THE best docus on Russian hardware out there. Western crap is just that, crap. Too full of propaganda (bashing Soviets and grandizing their own) that I stopped watching them years ago. Russians, on the other hand, stay on topic and deal mostly with facts not myths. :D

[Ironhand]

Yes. I know them. :) I was referring to how nicely that particular clip showed what the pilot was doing.

[rrohde]

This isn't exactly what I was pointing at. If the stick is pushed forward as in the video, after the nose levels it will continue moving downward.

 

I fly my cobra just like that; however, for the nose to not fall down, the cobra has to be initiated from about 600 km/h (and not much faster nor slower). Also, I sometimes enable the auto-leveling AP right after the maneuver to prevent the nose from falling as well. Works decently well for me.

[tovivan]

I fly my cobra just like that; however, for the nose to not fall down, the cobra has to be initiated from about 600 km/h (and not much faster nor slower). Also, I sometimes enable the auto-leveling AP right after the maneuver to prevent the nose from falling as well. Works decently well for me.

 

Any reason why not slower than 600? I've done them successfully at 300-350 and no problem.

 

And for some reason autopilot doesn't work for me, in no FC3 plane that I fly nor in Su-25T.

[rrohde]

Any reason why not slower than 600? I've done them successfully at 300-350 and no problem.

 

For me, slower speeds made it harder to prevent the nose from falling down - but that could be just my overall poor technique... :music_whistling:

[archer86]

600kmh is way fast for cobra, AFAIK that manoeuvre's optimum performans is between 300-350kmh.

I noticed that over 400kmh, aircraft gains too much altitude for cobra manoeuvre and I guess 600kmh is near limit for wing stress and possible damage which we'll see on dcs flanker with future updates

 

correct me if I am wrong:)

Edited January 12, 2016 by archer86

[rrohde]

Good to know! I will try this out and see how I fare. :)

[ShuRugal]

600kmh is way fast for cobra, AFAIK that manoeuvre's optimum performans is between 300-350kmh.

I noticed that over 400kmh, aircraft gains too much altitude for cobra manoeuvre and I guess 600kmh is near limit for wing stress and possible damage which we'll see on dcs flanker with future updates

 

correct me if I am wrong:)

 

A quick run through Wolfram Alpha estimates that at 90-degree angle of attack (used a Cd of 1) a 62 square meter surface moving at 600 kph at sea level on a standard day produces 10,076,000 kilogram-force of drag. Su-27 at 50% fuel is ~23,000 kilograms. 10M / 23k = 434 times the force of gravity on the plane.

 

So, yeah, no cobras at 600 kph.

[theropod]

which we'll see on dcs flanker with future updates

 

i dont have it but what i saw on the video, razbam m-2000 has wing damage

 

check 2:39

entering speed 770kmh

 

Edited January 12, 2016 by theropod

[archer86]

i dont have it but what i saw on the video, razbam m-2000 has wing damage

 

check 2:39

entering speed 770kmh

 

 

not same position but yes it has:)

[rrohde]

So, yeah, no cobras at 600 kph.

 

DCS certainly lets you perform cobras at that speed, however, I tested archer86's suggestion of doing the cobra at ~350km/h, and I agree - the handling is much more controllable, and there's hardly any altitude gained. So, I stand corrected! Thanks! :thumbup: