correct as-is Speed brake

[Convoy]

Probably something silly, but I bound the speed brake in controls, but it does nothing. I don't see a speed brake extending. 

Am I missing something?

[Archer.xd]

Speedbrake is automatically retracted if >540kts airspeed (this also means you cannot extend it while above that speed) 
or if you have landing gear down,
or if you have centerline fuel tank loaded.

(ED MiG-29A manual pg57 last paragraph explains)

Edited September 17 by Archer.xd
added manual ref

[Convoy]

2 minutes ago, Archer.xd said:

if you have centerline fuel tank loaded

That's it. Thank you!

[grim_reaper68]

thanks for the information

[Tabasc0]

How to deploy speedbrake constantly ? I mean, when i use the "sppedbrake depress" key, the speedbrake only deploys for a few seconds, then closes.

Thanks in advance !

[Q3ark]

16 minutes ago, Tabasc0 said:

How to deploy speedbrake constantly ? I mean, when i use the "sppedbrake depress" key, the speedbrake only deploys for a few seconds, then closes.

Thanks in advance !

Speedbrake in the fulcrum only stays extended for as long as you hold the speedbrake button, it retracts as soon as you release it. 

[Dudikoff]

Ah, that's useful to know, thanks. Was confused why there's only a toggle button for it.

[Q3ark]

1 hour ago, Dudikoff said:

Ah, that's useful to know, thanks. Was confused why there's only a toggle button for it.

You can negate this by binding it to a switch on your HOTAS,  it’ll stay out as long as you have the switch toggled on