EMB190 FLT CREW HAS TOW BAR COME LOOSE DURING PUSHBACK AND IS ALERTED BY PUSH CREW. PARKING BRAKE SET WITH ACFT MOVING CAUSING ABRUPT STOP.

Narrative

DURING PUSHBACK FROM GATE; GND CREW ALERTED FLT DECK TO SET PARKING BRAKE IMMEDIATELY (YELLING LOUDLY COMMUNICATING URGENCY). TOW BAR BECAME DISENGAGED FROM NOSE GEAR AND WITH PARKING BRAKE SET ACFT LURCHED VIOLENTLY. WE IMMEDIATELY CALLED TO CABIN VIA INTERPHONE TO ASCERTAIN IF ANY CREW OR PAX WERE INJURED. FLT ATTENDANTS INDICATED THEY WERE STARTLED BUT NO ONE WAS INJURED. WE THEN MADE A PA TO PAX ADVISING WHAT HAD HAPPENED AND TO REMAIN SEATED AS WE CALLED FOR A MECH TO INSPECT NOSE GEAR FOR ANY DAMAGE AND TO ASCERTAIN WHAT ACTUALLY OCCURRED. MECH ARRIVED WITHIN 3-4 MINS AND ADVISED US THAT THERE WAS NO DAMAGE AND ACFT COULD CONTINUE OP. HE ALSO ADVISED US THAT THE TOW BAR WAS NOT ENGAGED TO THE NOSE GEAR CORRECTLY THUS CAUSING THE PREMATURE DISCONNECT. FROM THE FLT CREW PERSPECTIVE WE BELIEVE THE EVENT OCCURRED DUE TO FATIGUE/INSUFFICIENT TRAINING OF GND CREW ON PROPER PUSHBACK PROCS/EQUIP USE. GND CREWS MAY NEED ADDITIONAL TRAINING/SUPERVISION AND/OR NEED TO TAKE MORE TIME/PRECAUTION TO ENSURE SOP'S ARE CLOSELY FOLLOWED.