Medium Transport; Low Wing; 2 Turbojet Eng
Flight Crew Air Transport Pilot (ATP)
Human-Machine Interface; Training / Qualification
Conflict Ground Conflict; Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Loss Of Aircraft Control
Flight Crew Regained Aircraft Control
Human Factors; Procedure
During pushback and prior to engine start we told the push crew to 'tail us' at a 45 [degree angle per ramp control]. About half way through pushback the tug drive started calling; 'Set brakes. Set brakes. Set brakes!' As we were still moving backwards I asked him what was going on. I was told that; 'They forgot to hitch the tow bar to the tug.' The plane was now rolling straight back with everybody onboard across the ramp not connected to anything. I gently applied one brake to stop the plane without tipping it onto its tail. As a result the plane stopped straight back (as opposed to a 45) and way out in the center of the ramp. Nose wheel on our taxi line. Tail hanging out over the opposite taxi line. If there had been another plane in the lane behind us we would have smashed into it for sure. All ground crews should receive additional training on connecting the tug to the aircraft. Have a Supervisor check the connection of the tow bar between the tug and the aircraft prior to push as a back up/second opinion.
Only after pushback had begun did the ground crew realize the tow bar was not linked to the tractor and the aircraft was rolling backwards on its own and alerted the flight crew. The Captain was able to cautiously halt the backward motion and set the brakes before any contact occurred.