A319
Flight Crew Air Transport Pilot (ATP)
Distraction
Conflict Ground Conflict; Critical; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural FAR; Ground Incursion Taxiway
Flight Crew Took Evasive Action
Aircraft; Human Factors
We were taxiing northbound on G taxiway and already in the right turn on to Y taxiway. The jumpseater sitting behind my seat started tapping me on my left shoulder and shouting Sir; Sir; Sir and stop; stop; stop! When I looked to my left; while braking very hard; a single engine prop plane was approaching from the left at a very high rate of speed. He was told to give way to us by ATC Ground Control.He was taxiing so fast; that I never saw him when I cleared left before my right turn. Fortunately I was only going about 9 knots when I began my right turn. There was only one pilot and no pax as far as we could see in his aircraft. He never deviated to his left to avoid us and my next concern was his wing hitting our nose. Fortunately; it missed. Had it not been for the jumpseater seeing him and alerting me; this would have been a much more serious outcome. The sun was to our right (clear skies) and he was to our left. I don't know how he couldn't have seen us; since the Airbus 319 is 'large' compared to the aircraft he was in.I think that the pilot operating that aircraft needs to taxi considerably slower than he was. He was taxiing in excess of 30 knots. I also think he was not aware of our presence due to him not even attempting to miss us. A discussion with him by the FAA should take place at a minimum.
An A319 air crew; while taxiing for departure; was alerted by their cockpit jumpseater of an imminent collision hazard with a single engine prop aircraft. The aircraft had been instructed to give way to the A319 and was taxiing at a very high rate of speed. Hard braking by the A319 crew prevented a probable collision.