B777 Undifferentiated or Other Model
Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 194.85; Flight Crew Total 15940.07; Flight Crew Type 2563.80
Situational Awareness; Communication Breakdown; Confusion; Distraction
Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Loss Of Aircraft Control
General None Reported / Taken
Equipment / Tooling; Human Factors; Weather
An un-commanded aircraft movement occurred while the parking brakes were released that caused the airplane and the attached tug to move backwards approximately 5 feet.First Officer noticed the movement; informed me and I promptly applied and set the parking brakes. I contacted the ground personnel on the head set to see what could have caused the movement. Ground personnel told me; the hand brakes on the tug were set and the aircraft started moving because of the winds.Considering the tug was attached and occupied throughout this incident and we were in full communications; I asked why they did not alert us that the aircraft was moving? They had no response. I told them; next time; not to be silent but instead speak up. He agreed!
B777 Captain reported un-commanded aircraft movement while at the gate prior to departure.