Autobrake disarms on touchdown

[rob345 3]

It happens quite often to me (~20% of all landings) that the autobrake disarms immediately at touchdown (without doing anything like manual breaking, retracting spoilers, etc).

 

At first I had the "bouncing issue" that is described in the manual in mind, because - maybe - it would let the aircraft shortly being airborne again for a split second so that the autobrake would disarm. But no, I changed the mesh as recommended and it happens anyway.

 

I also remember that users reported that for the NGX - does anybody still remember what was the solution for that?

 

[MarkVcz 2]

I'd love to know more information on this topic. It happens from time to time.

[rgamurot 1]

With the NGX (and the 777) it's almost always 'noisy' pedel hardware. You can test this by disconnecting your pedels during a landing and see if this still happens. Also, if you have the parking brake kicking off at the gate a lot; even with the lightest touch to the pedels, it's probably your hardware.

[ArjenVdv 190]

I've had this problem as well and found these things are causing it:

1. Having a reverse thrust axis mapped through FSUIPC that is spiky.

2. Having your brakes calibrated/assigned though both FSX and FSUIPC at the same time. I recommend calibrating them to FSX only.

3. Using reverse thrust on a RTO will always disarm the autobrakes, this is realistic.

4. Although I don't have any personal experience with this, faulty hardware that causes spikes.

[Skysurfer007 7]

I have the same problems, was ale to fix it for the NGX, now with the 777 same problem again... 

- I have now problems with disarming the parkingbrake.. for that I need to press my pedals have way down.

- It happens 90% of my landings.. no matter whicht brake level I select

 

3. Using reverse thrust on a RTO will always disarm the autobrakes, this is realistic.

 

This can´t be realistic as the reject drill includes raise the speedbrake, apply max reverse thrust and only IF the autobrake disconnects, ensure max manual braking! 

[Skysurfer007 7]

I think the problem is, that one condition for the autobrake activation is -> throttles idle. My throttles are only in complete idle when on the ground, regardless of A/T armed or not. On the ground they work fine.. in the air if I retard them, they go back to the idle detend and then move i little forward again - as I said, on the gorund that does not happen!

 

So during autoland, the throttles move back to idle but very slow and as the main wheels touch down, the throttles are still not completely idle - which leads to autobrake disarm... - my opinion.

 

Let me know what your throttles do.

 

Cheers,

Berni