Flight model - different joystick, different behavior when full flaps are extended

[Vita_CZ]

Greetings to developers!

We have found this interesting behavior while flying in multicrew setup, but the behavior is the same in single player too. What happens:

I have two joysticks - Sidewinder FF2 and Saitek X-52. While flying on final approach with Sidewinder, I have speed arround 250 km/h, aircraft trimmed and flaps in take off position. When I extend full flaps now, aircraft just puts it's nose down little bit and continues most likely as-is, which is correct and I would expect this.

 

In the same situation, using Saitek X-52, (speed 250, flaps in takeoff position, aircraft trimmed) when full flaps are extended, aircraft nose goes up and aircraft starts climbing. That's strange I think and it should basicaly do the same as if flown by Sidewinder. Using the Sidewinder primarily, I was not aware of this behavior when different joystick is used and I yelled at my student pilot many times what the hell is he doing with the pitch on final, but by further investigation shows that it was not his fault :-)

 

Would you please mind to look at these differences?

 

Thank you!

Vita

[msalama]

Have you tried to recalibrate the X-52?

[Vita_CZ]

it's not about the calibration.

1) The aircraft was trimmed, so there was no need for stick input as it flew

2) Two different instances of X-52 were tested on 2 different machines in two different geographic locations :-), both with the same result

[Ramsay]

What you see is likely due to switching between a Force Feedback joystick and a regular joystick.

 

When you adjust trim on your Sidewinder FF2 - it is done by the joystick changing it's centre position (and hence input).

 

For a regular stick - the centre position and input stay the same (zero) and trim adjustments to the in game flight stick are made using offsets to the 'real' joystick centre (zero).

 

Ideally, force feedback and regular sticks would be in sync and it might be WIP, on the other hand, it may be very difficult to do and is a design limitation of multi-crew control switching.

 

Edit:

However, if you are saying, when trimmed on final, changing from TAKE-OFF flaps to LANDING flaps - the L-39 gives a different flight reaction depending on stick used

 

• 
  
• slight pitch down for Sidewinder FF2
  
• pitch up for X-52
  

that is an important find.

 

For my X-52 Pro - I see a pitch up and assume every one else does too ?

Edited February 22, 2016 by Ramsay

[Dr_Arrow]

This might be a correct behavior. Because when flaps are extended to landing position a special servo compensator moves the left elevator trim tab down. So at first there is a pitch down moment from the landing flaps and after servo compensator moves the trim tab down putting the elevator in its previous position. The FFB stick does the same, it also first moves slightly forwards with pitch down flaps moment and then slightly backwards compensating it. Because non-FFB stick does not move this causes the plane to pitch up. Hope it is understandable. This is also described in RL manual and with FFB stick the plane behaves this way. I have a G-940 and it replicates this RL behavior - at first there is slight pitch down (stick goes forward) after compensator kicks in and the trim tab moves and stick goes back and the plane remains neutral in moments.

 

I would moreover add that the left trim tab is animated and you can see it moving down when you extend flaps to the third position effectively moving the elevator up - you can see it in ctrl+enter view.

 

When I disable FFB the plane indeed pitches up, because the servo compensator moves the elevator up.

Edited February 22, 2016 by Dr_Arrow
Added and corrected some info after testing

[badbud]

My X-52 does the same thing,

BadBud

[Vita_CZ]

However, if you are saying, when trimmed on final, changing from TAKE-OFF flaps to LANDING flaps - the L-39 gives a different flight reaction depending on stick used

 

• 
  
• slight pitch down for Sidewinder FF2
  
• pitch up for X-52
  

that is an important find.

 

 

Yes, that's exactly what happens.

 

Dr_Arrow - I (hopefully) understand what happens in real aircraft. Also agree with the statement that behavior with FF joystick in the sim is closer to real thing, but I don't understand why the behavior should differ with non FF joystick in simulator.

 

Vita