Human-Machine Interface; Distraction
Aircraft Equipment Problem Critical; Ground Event / Encounter Object; Ground Event / Encounter Loss Of Aircraft Control
Flight Crew Regained Aircraft Control
Aircraft
As we approached our assigned parking spot the Marshaller gave us the signal to stop. I stopped the aircraft; set the parking brake; and shut down the Number 1 engine. As we waited for external electrical power to be connected; I removed my headset and turned to stow it in its cubby. At this point; my First Officer shouted that we were moving. We both immediately applied toe brake pressure and the aircraft came to an abrupt stop. We glanced down at the center console and confirmed that the parking brake was indeed set. The aircraft travelled approximately 6 to 10 feet with the Number 2 engine at idle thrust and the parking brake set. The Mechanic hooked up and told us that the aircraft would have to be pushed back into its parking spot with a tug. I told him that we had had a parking brake failure and were holding toe brake pressure to keep the aircraft from moving. Fortunately no ramp personnel were injured. The aircraft nose wheel struck a chock but neither the aircraft nor the ramp equipment was damaged.
[No additional information from Narrative #2.]
After setting the parking brake upon gate arrival the flight crew of an A300 was surprised when the aircraft; with an engine still running pending connection of ground power; moved forward several feet. The aircraft was stopped using toe brakes which were functional.