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GreatBelt
31st Oct 2012, 10:16
Does anybody know if the Auto Brake system on the A320 will activate with PARTIAL ground spoiler extension or if full ground spoiler ext. is required?

HPbleed
31st Oct 2012, 10:30
FCOM DSC-32-30-10 P7/14

Automatic braking is activated

-at the command for ground spoilers extension, for LO and MED
-at the command for ground spoilers extension and the aircraft speed is above 40 kt, for MAX mode.

(Bearing in mind that command for spoilers will not activate until above 72 kt anyway)

So to answer your question it's at the command for spoilers, nothing to do with how far they're deflected.

Airmann
31st Oct 2012, 11:21
I think that GreatBelt may be alluding to the situation in which only one set of main LDG gear make contact at touchdown and there is only a partial deployment of spoiler to soften the contact of the other gear DSC 27-10-20 (p10/24). In this case I wouldn't want brakes to be activated due to partial spoiler deployment because only one set of gear is in contact with the ground.

GreatBelt
4th Nov 2012, 14:03
Spot on. Airbus has changed the logic of the Ground Spoiler extention on newer models, so that you get a PARTIAL spoiler extention with ONE main wheel on ground and TL idle. On older models you need ONE main wheel on ground and one TL in REVERSE.

The FCOM states that the Auto Brake will activate when the Ground Spoilers extent. If that is also the case with PARTIAL ground spoiler extention, in my opinion if you land in strong xwinds, auto brake MEDIUM you will be in for a very nasty surprice with the new ground spoiler logic, because the braking will start 2s after you touched down, still rolling on only ONE main wheel.

Anybody, knows how the Auto Brake activation works with the implementation of the new Ground Spoiler logic (SEC 120 update)?