A319
Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Flight Crew Last 90 Days 148; Flight Crew Total 1115; Flight Crew Type 1115
Distraction; Human-Machine Interface
Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Loss Of Aircraft Control
Flight Crew Became Reoriented; Flight Crew Regained Aircraft Control
Human Factors
After pushback ramp used proper verbiage to have us set the brakes. The parking brake was set if I recall correctly. I did check the pressure was normal. However; when the Ramp requested to disconnect; I think I released the parking brake again for some reason that I cannot fathom. At this point the Ramper told us over interphone the aircraft was rolling forward; and I looked down and the parking brake was not set. I stopped the aircraft which was rolling so slowly that the movement was imperceptible from the flight deck and set the parking brakes.
A319 Captain reported distraction and failure to set the parking brake caused the aircraft to roll forward at the gate.