Erj-175 flight crew reported rolling away from the gate after the tow bar became disconnected during...

Narrative:

The aircraft was late arriving. Our departure was delayed as a result. After closing the doors and completing the before start check list I turned on the ramp on my audio panel and the tug driver was already saying they were ready for the brakes. I released the brake and told him we were calling for push. Ramp control told us to push. I relayed that to the tug driver. Just as we started to push back the ACARS came in with the gate information. My first officer looked down to copy that information onto a piece of paper. At about the same time I looked at my ipad to check the taxi diagram and the ramp diagram to see if there was anything special about this area I was forgetting. I looked up from my ipad to see the wing walker looking towards the nose of the plane with his arms in an X. I quickly looked towards the front of the plane and saw the tug that I thought was pushing us over 20 ft away. We were still moving backwards. The tug driver was also holding his arms in an X. I stepped on the brakes and after the plane stopped reset the parking brake. Apparently the tow bar had never been properly connected to the plane and had simply fallen off after they started to push us. The tug drivers head set was damaged when the plane rolled away from the tug so we had to push back with hand signals after they reconnected the tow bar.

Original NASA ASRS Text

Title: ERJ-175 flight crew reported rolling away from the gate after the tow bar became disconnected during pushback.

Narrative: The aircraft was late arriving. Our departure was delayed as a result. After closing the doors and completing the before start check list I turned on the ramp on my Audio panel and the tug driver was already saying they were ready for the brakes. I released the brake and told him we were calling for push. Ramp control told us to push. I relayed that to the tug driver. Just as we started to push back the ACARS came in with the gate information. My first officer looked down to copy that information onto a piece of paper. At about the same time I looked at my iPad to check the taxi diagram and the ramp diagram to see if there was anything special about this area I was forgetting. I looked up from my iPad to see the wing walker looking towards the nose of the plane with his arms in an X. I quickly looked towards the front of the plane and saw the tug that I thought was pushing us over 20 ft away. We were still moving backwards. The tug driver was also holding his arms in an X. I stepped on the brakes and after the plane stopped reset the parking brake. Apparently the tow bar had never been properly connected to the plane and had simply fallen off after they started to push us. The tug drivers head set was damaged when the plane rolled away from the tug so we had to push back with hand signals after they reconnected the tow bar.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	1517252
Time
Date	201802
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Light	Dusk
Aircraft 1
Make Model Name	EMB ERJ 170/175 ER/LR
Operating Under FAR Part	Part 121
Flight Phase	Taxi
Flight Plan	IFR
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Total 4800
Person 2
Function	Pilot Not Flying First Officer
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Type 650
Events
Anomaly	Deviation - Procedural Published Material / Policy Ground Event / Encounter Loss Of Aircraft Control

Erj-175 flight crew reported rolling away from the gate after the tow bar became disconnected during pushback.