A320
Flight Crew Air Transport Pilot (ATP)
Troubleshooting
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Landed in Emergency Condition; Flight Crew Overcame Equipment Problem; Flight Crew Diverted
Aircraft
We started the day with an auto-brake fault MEL. The manual brakes worked normally; we simply couldn't use the auto-brakes. After takeoff; we received the brakes auto brake fault ECAM; with brake released below it. We were expecting the brakes auto brake fault ECAM; but not the brakes released because in the original MEL; it stated that it cannot be displayed to legally dispatch the plane.We ran the ECAM procedures. After going thru the QRC; QRH and Aircraft Operating Manual (AOM); we learned that at least one wheel will be released. This was the primary concern because we didn't know if multiple wheels would not be braking.The Captain did all of the communicating with dispatch and maintenance. Then the confusion came getting landing numbers. The inflight performance for the A320 has performance numbers for the auto brake fault and dispatch was able to give us numbers with one brake released. But they couldn't give us numbers for 2 brakes or more released. They were discussing our current MEL with the new issue and no one was able to explain if more than one brake would be released.The landing airport was calling for rain and with about 7;600 feet available for landing. With one brake released we needed about 5;600 feet to stop. What we didn't know is if more than one brake was going to be released. This resulted in us [advising ATC] and diverting to another airport to use their long runway.There is so much that can be learned from this event. We tried to use every available resource to make the best decision we could with what we knew at the time. And of course safety is always number one. I have just learned that for the A320; the auto brake numbers take into account for one wheel to be released. What I also didn't know is that if a second wheel was released there would have been a second ECAM.We actually talked about this during the flight of how we would know if 2 or more wheels were released and we simply didn't know. According to the AOM; it was entirely possible more than 1 brake could be released. If we just knew that; we would have been so much more comfortable with the situation. I also learned to just stick with the ECAM and don't assume more things can be broken than what the airplane tells you.
Aircraft dispatched with auto-brakes inoperative. After takeoff a brake system fault indicated there would be less than full brakes available. The crew diverted to a long runway airport; advised ATC; and landed normally.