The following is an excerpt from a
blog:
His second landing was a smooth touchdown in a strong right crosswind. He had auto-braking selected ON... Not a bad idea for a low time Electric Jet pilot. He should have held more stick into the wind after touchdown, because a gust lifted the right wing and main landing gear off the runway just before the spoilers rose and exactly when the auto-brakes activated. Yikes!
The auto-brake computer could not handle one main gear on the runway and the other still airborne, so it said see ya later boys, and, by the way, I am taking number four brake with me.
Yellow caution lights illuminated the flight deck with a warning bell from the aircraft monitoring system... AUTO-BRK FAULT and BRK RELEASED.
I calmly told the kid to Use max reverse thrust and max manual brakes; don't pump them. Number four brake is gone.
The question asked was why the system would deactivate the #4 brake. Having never flown an Airbus, I could only guess what was going on. Here's my theory:
When the wind lifted the wing, the #4 wheel came off the ground just enough for the anti-skid system to interpret it as a skidding tyre, and thus released the brake pressure. With conflicting signals from the air/ground sensing system nicely timed with the anti-skid logic, the system released the brake.
That's my explanation of why it was initially released. Now I'm wondering why it stayed released until maintenance reset the computers.
What do the Airbus experts say?
Edit: Seems pprune is preventing the blog address from being linked properly. Here it is:
flightlevel390.********.com/2012/03/approved-for-line-operations.html
******** = "blog spot" (without the space)
PS. can anybody tell me why the forum software is censoring a blog hosing website? Does the airline that shall not be named own that as well?