Is something wrong with the L-39 flaps and trim system?

[Grippen7]

Is something wrong with the L-39 flaps and trim system? :cry:

 

During take-off with the flaps in the take-off position, the L-39 rotates very quickly on its tail.

The flaps give a strong pitch up moment.

It also looks that the trim system is reversed.

If I want to trim the plane up I have to trim it down.

The stick and the elevator dont match up.

I feel that something is wrong with the Trim action vs Stick animation vs elevators animation vs trimtabs animation.

If I trim up, the stick goes aft and the elevators up, but the nose of the plane goes quickly down.

Looks that the right trimtab is going down which must be correct and the left trim tab stays neutral.

Also the flaps shoud give a nose down moment instead of up.

I uninstalled the module and after reinstallation nothing changed.

I cant remember that the L-39 flew like this before, because this was the first module I bought and never had the extreme tailstrikes before.

 

 

Best regards, Grippen7

Edited May 8, 2019 by Grippen7

[Nooch]

I flew the L-39 yesterday, did a take off roll and did not notice any of that.

[Grippen7]

I flew the L-39 yesterday, did a take off roll and did not notice any of that.

 

I have this problem before and after the latest patch, also after a comlete new installation of the L-39 module.

Try the instand take off mission from the caucasus.

After a few meters I get a tailstrike if I dont push the stick almost full forward.

[gulredrel]

Can't speak for the OB, as I'm on stable version. There L-39 works correctly.

Have you checked you axis assignments? Sounds to me like something got mixed up. You could also open controls indicator window and check if your hardware stick movements are as expected.

[Grippen7]

Can't speak for the OB, as I'm on stable version. There L-39 works correctly.

Have you checked you axis assignments? Sounds to me like something got mixed up. You could also open controls indicator window and check if your hardware stick movements are as expected.

 

I did.

I also reasigned all the trimbuttons again and recalibrated my CH joystick and throttle assy's.

I checked also the controls indicator window in the cockpit view.

It is some problem in the module i think. :cry:

[Ramsay]

It is some problem in the module i think. :cry:

Please post a track so we can see what's wrong and/or recreate your problem.

 

Note: Takeoff Elevator trim is 2 marks down (or greater with more weight/drop tanks).

 

Instant Action > L-39C Takeoff, Beslan RWY 10 (100% fuel/GTW 4458 kg)

 

• L-39C takeoff was smooth and controlled in DCS Open Beta 2.5.4.30386 using a force feedback stick with takeoff trim set at 2 marks 'nose down'.

Edited May 9, 2019 by Ramsay
Test Instant Action > L-39C Takeoff in DCS Open Beta 2.5.4.30386

[Ramsay]

Also the flaps should give a nose down moment instead of up.

• The L-39C is missing the weight and canon of the ZA and is 'tail heavy'.

• Extension of the ZA's flaps for landing causes a 'nose-up' moment that must be trimmed out.

 

Hence the need to trim nose down (RL manuals and pilot notes differ on the amount).

 

AFAIK the ZA has a more 'neutral' takeoff trim than the C but I haven't checked if that's the case in DCS.

[msalama]

Works correctly for me. You sure you don't have any easy flight options on?

[Grippen7]

Works correctly for me. You sure you don't have any easy flight options on?

 

 

YOU ARE THE WINNER msalama !!! :thumbup:

 

This was the real problem.

The Game Flight mode was been activated for an unknown reason.

After deactivating this option, everything returned to normal.

Can this option be activated during an update, because I have never used it before?

 

Thanks to everyone for the good advice.

 

Now I can fly happily again in my L-39 module. :pilotfly:

 

PS: I tested with "Game Flight Mode on and off and this was the real cause.

 

Strange that a "Game Flight Mode" flies more difficult than the real Flight mode. :smilewink:

 

Kind regards, Grippen7

[Nooch]

Nice to see you got the issue sorted! This is why I had advocated for removing game flight mode in the past. Very few people use it and it's not even working correctly in several modules, creating problems for people who enable it by accident.

[msalama]

Excellent! Glad you got it sorted mate :thumbup:

[Grippen7]

Excellent! Glad you got it sorted mate :thumbup:

 

Thanks again and have a nice weekend.

 

Grippen7

[msalama]

You too mate! :beer:

[redbaron83]

My apologies if this has been addressed in another thread.  I cannot get the L-39 to stay trimmed during flight.  I can trim for straight and level and after a few seconds it will start a gentle dive that progresses and cannot be trimmed out.  Also, when the elevator is pulled to a full up position it does not return to neutral but instead stops it's return at about 1/3 to 1/2 up elevator ( I noticed this on the ground after a few tail strikes during takeoff).  I didn't know what was causing them but now it's obvious.  When pushed to the full down position the elevator returns to neutral as it should.  Any ideas, anybody?  

Edited February 22, 2021 by redbaron83
word was left out

[NineLine]

Would be better for you to open a new thread with a track of your issue, it doesnt seem related here. Thanks.