Takeoff procedure vs real aircraft

[Helios1138]

The official manual says that you have to raise the nose at 90kph. I flew in the real Yak (pilot seat but the takeoff was done by the instructor) and watched a bunch of cockpit videos that basically show it behaving as described. In DCS, however, the nosewheel cannot be raised at 90kph no matter how much I pull on the stick. It only comes up at something like 120kph it seems. It also sometimes does this very violently, so I even have to apply a forward stick to keep the angle manageable. The trim is kept neutral during this.

 

Am I doing something wrong or is this an issue with DCS flight model?

Edited June 29, 2020 by Helios1138

[Toriy]

Why do you keep the trim neutral?

[IvanK]

The statement in the manual doesn't mean you physically get the nose gear off the ground at 90 Kmh. The idea is to reduce the load on the nosewheel by applying some bacstick.

[Toriy]

Actually this is possible in DCS to raise the nosewheel at 90kph and lift off at 120. You just need to set the trim for take-off position according the manual and put 2 pilots unto the cockpit. And try not to use curves for your controls. FFB with a centring spring helps me a lot. Start rotation at 75-80 and as soon you notice that the cowl is raising stop back pressure on the stick, fix it, may be with a small forward pressure, (do not allow the cowl to go high and block the visibility of the far end of the runway until the plane lifts off,) and from this moment just wait until the plane lifts off at 120 kph and be ready to use the stick to prevent tail strike and not allow her to go for high AoA immediately after her lifting off. Just try this 5-6 times.

Edited June 29, 2020 by Toriy

[Helios1138]

Why do you keep the trim neutral?

 

That’s what the instructor on my flight did. Also, it’s what the manual says to do when 2 pilots are present

 

The statement in the manual doesn't mean you physically get the nose gear off the ground at 90 Kmh. The idea is to reduce the load on the nosewheel by applying some bacstick.

 

Possibly. Although looking at

for example, you can see that the nose is actually starting to rise at 90 to 100 and at 120 he’s already airborne. In DCS it seems the nose only starts rising at 120. Edited June 29, 2020 by Helios1138

[Toriy]

That’s what the instructor on my flight did. Also, it’s what the manual says to do when 2 pilots are present

 

Possibly. Although looking at

for example, you can see that the nose is actually starting to rise at 90 to 100 and at 120 he’s already airborne. In DCS it seems the nose only starts rising at 120.

 

 

I prefer to trim with 2 pilots as well. However it works perfectly with neutral trim for to pilots like in the manual. I've done one quick video

[Toriy]

And one more video with a trim like for 1 pilot but with 2 pilots

[Helios1138]

I've done one quick video

 

Thanks for that! Now at least I know that the flight model is capable of this, I will attempt to correct things on my end :)

Edited June 30, 2020 by Helios1138

[Fishface68]

On 6/30/2020 at 3:34 PM, Helios1138 said:

 

Thanks for that! Now at least I know that the flight model is capable of this, I will attempt to correct things on my end

 

This is over rotated, you wouldn't want to do this in the real aircraft. The procedure for take off is trim set for take off (which is slightly nose up) 70% on the brakes, release and smoothly open the throttle. Hold the stick aft of neutral and keep her straight with the rudder. nose should come up at 90, off at 110/120, hold the attitude for positive rate, gear when out of runway. throttle to 800mmHg prop 82% trim for 170kmh and climb away keeping the ball in the centre. I have a good illustrated flight manual that was translated from russian if that would help?

 

[Toriy]

A good video comparing the DCS Yak-52 and a real one. CC translation is good enough. In short - IRL, if you apply back pressure from the beginning, the Yak with one pilot in the 1st cabin lifts off - jumps into the sky on high AoAs - much earlier than the manual states. With a risk to damage the tail and all other high AoA risks and over rotating at 70 kph, but she is able to lift off at 85-90 kph and not on 120. The manual states that you have to start rising the nose at 90 and lift-off at 120 just for safety of young pilots reason.

Edited February 11, 2021 by Toriy