Commercial Fixed Wing
Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Flight Crew Last 90 Days 106; Flight Crew Total 9610; Flight Crew Type 9610
Communication Breakdown
Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Ground Equipment Issue; Ground Event / Encounter Loss Of Aircraft Control
Flight Crew Regained Aircraft Control
Human Factors
Pushing back; all was normal until the push was completed. At that time the Tug Driver said; 'pushback complete' but did not say 'set brakes'. I asked him; 'do you want the brakes set?' and there was no reply. I asked again; 'do you want the brakes set?' There was an unintelligible response and I said; 'I did not get that do you want me to set the brakes?' There was another unintelligible response and the aircraft was lowered to the ground from the tug. I was very alert at this point and immediately noticed the aircraft moving. I set the brakes as the Tug Operator said; 'set the brakes!'I responded that I had asked him several times if he wanted me to set the brakes.He then apologized and told me that the aircraft was disconnected and the by- pass pin removed. There was no one hurt the flight proceeded normally.
On pushback the Tug Driver reported the push complete; but we did not hear him say set the brakes. The Captain asked if he wanted the brakes set at least twice with no response. We could feel the nose being lowered and were on alert. The Captain felt the aircraft move and immediately set the brake and the Tug Driver stated 'set the brakes' at the same time. No injuries and flight proceeded normally.
Air carrier flight crew reported ground crew's failure to properly communicate; resulted in the aircraft moving after tug disconnect.