A320
Flight Crew Last 90 Days 220; Flight Crew Total 11200; Flight Crew Type 9000
Aircraft Equipment Problem Less Severe
Flight Crew Landed in Emergency Condition; Flight Crew Returned To Departure Airport; General Declared Emergency
Procedure; Aircraft
While climbing out on the departure; BRAKE: SYS 2 FAULT appeared. As we continued to climb and began to comply with procedures; BRAKE: AUTO BRAKE FAULT appeared. The captain elected to remain in US air space and hold as we began discussing problem with Dispatch and Maintenance Control. The Captain kept flight attendants informed. Of particular interest was the status page which indicated the following 4 inoperative items: CAT 3 DUAL; Normal Brakes; Auto Brakes and Brake Sys 2. We were puzzled by Normal Brakes being inoperative given that only Brake Sys Fault 2 was on the upper ECAM. Maintenance Control could not decipher why we had that indication. If normal brakes were inoperative; shouldn't we also have a BRAKE SYS 1 FAULT? We elected to return; declare an emergency and operate under the assumption that we would decelerate with ALTERNATE brakes. We landed without incident using ALTERNATE brakes. I monitored and called out pressures from the triple brake indicator as the Captain decelerated. NWS worked so we taxied to the gate.
After printing paperwork for flight; reviewed maintenance history and Open Inbound Defect Reports. Received call from Dispatcher stating that he turned down aircraft for brake history. Waited in operations until notified that Maintenance replaced BSCU and cleared aircraft for departure. Completed normal preflight and pre-departure checks. On climb passing 7;000 feet BRK SYS 2 FAULT and BRK AUTO BRK Failure Ecams annunciated. Completed ECAM procedures and reviewed Status page indicating Inop Systems: CAT 3 DUAL; NORM BRK; AUTO BRK; BRK SYS 2. After brief discussion and review of maintenance history; contacted Dispatch and Maintenance Control through ACARS and voice. It was determined and agreed that continuing to destination with current aircraft status was not feasible. Requested delaying vectors and holding from Center. Maintenance Control stated that the ECAM/Status information did not make sense and with current fault information; could not determine the exact aircraft failures/condition. Declared an emergency; briefed the flight attendants on aircraft status and divert plans; and announced to passengers the plan for a return. After consultation with Dispatch and Maintenance Control; it was determined that the worst case scenario for landing would be alternate brakes; no anti skid; and no nose wheel steering. Landing performance and procedures for landing with alternate brakes and possible failure of nose wheel steering was reviewed and briefed. A normal ILS approach was flown by the Captain in visual conditions. At touchdown it was determined that braking was alternate yellow system braking with fluctuating pressure indicated on Brake Pressure Gauge. First Officer called pressures during rollout and remained below 500 psi during rollout. After determining nose wheel steering availability exited runway and stopped on taxiway for systems status check. Normal taxi and shutdown.
A320 flight crew accepts an aircraft after a BSCU change and during climb passing 7;000 feet BRK SYS 2 FAULT and BRK AUTO BRK Failure ECAM's annunciated.  Status Page indicates NORM BRK; AUTO BRK; BRK SYS 2 have faults and the crew elects to return to the departure airport. After landing braking is via Alternate Brakes and the nose wheel steering is functional.