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View Full Version : 737 NG Anti Skid Inop


mona lot
3rd Apr 2009, 18:34
Following failure of the Anti Skid in flight, the QRH directs you NOT to arm the speed brake. I understand automatic speed brake deployment may be inoperative but why can't you arm it anyway.

msr001
5th Apr 2009, 00:18
If you understand that automatic speed brake deployment may be inoperative so why do you want to arm it ?
Maybe you are directed not to arm it so that you remeber to deploy it manually.

FCS Explorer
5th Apr 2009, 22:00
Condition: The ANTISKID INOP light illuminated indicates a
system fault is detected by the antiskid system.

"a system fault" .... maybe boeing doesn't really know what might happen and fears the spoilers could deploy at the wrong time all by themselves or triggered by ??? ...?

Mshamba
6th Apr 2009, 07:29
Sometimes i think this "system" operates by witchcraft. If you're on the ground and "antiskid inop" illuminates check if parking brake is set. If so, release parking break. "Antiskid inop" is off and you can set the parking brake again, just a failure in some very strange... ummm system ;)

Rainboe
6th Apr 2009, 14:56
It's very neat. Anti-skid can't work if the park brake is set, so it's telling you anti-skid is off!

Mshamba
7th Apr 2009, 10:18
If you're on the ground with parking brake set or not - the "antiskid inop" light is supposed to be off, and thankfully it is.

Flight Detent
8th Apr 2009, 02:25
...from the above...

Do any of you guys, with the possible exeption of Rainbow, know what the relationship is, between the parking brake and the antiskid system?

Cheers...FD...

Capt Chambo
8th Apr 2009, 06:20
I understand automatic speed brake deployment may be inoperative but why can't you arm it anyway.

I seem to remember something about the possibility of getting "Ground Spoilers" when deploying the "Flight Spoilers" in flight, but not 100% sure without diving into the books.

Boingboingdriver
8th Apr 2009, 15:50
The only way i know which would get the Ground spoilers to deploy in the air would be if you are using the Flight spoilers in the AIR and you have an Ground/Air logic failure..example you take off and the gear will not move up after take off..you retract the flaps and the config horn still sounds...then you are in trouble:( including that you MUST NOT use the speed brakes in flight until you have actually landed....hope that helps...:cool:

And to answer the initial question..i think boeing doesnt want you to arm the speedbrakes for Landing as by having the speedbrake in down detent it will DISARM the autobrakes system...i dont think any of us would like a fault in the antiskid system to malfunction by giving unwilling inputs to random wheels as you touchdown(wheels spinning)..could be interesting...
After landing if needed using manual braking is possible as it reduces your stopping distance which also is an alternative way to disarm the antiskid..:E