B737 captain reported ramper failed to secure the tow bar resulted in the aircraft freewheeling.

Attributes
ACN	1669527
Time
Date	201907
Place
Locale Reference	ORD.Airport
State Reference	IL
Aircraft 1
Make Model Name	B737 Next Generation Undifferentiated
Operating Under FAR Part	Part 121
Flight Phase	Taxi
Flight Plan	IFR
Person 1
Function	Captain
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Multiengine Flight Crew Instrument
Experience	Flight Crew Last 90 Days 147
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Procedural Published Material / Policy Ground Event / Encounter Loss Of Aircraft Control

Narrative:

Aircraft was on push back when tug diver stated 'oh @#$%' I inquired what 'oh @#$%' meant. At that that point the driver called 'break away; break away.' I immediately stopped the aircraft and set brake. I advised 'break set; pressure normal.' the driver informed me that another ramper failed to secure the clamps on the tow bar and once the push began the aircraft was freewheeling. I entered an elb (electronic logbook) report and advised maintenance that an inspection was needed. Maintenance visually inspected and cleared aircraft for operations. Push back continued without further incidents.

Original NASA ASRS Text

Title: B737 Captain reported ramper failed to secure the tow bar resulted in the aircraft freewheeling.

Narrative: Aircraft was on push back when tug diver stated 'oh @#$%' I inquired what 'oh @#$%' meant. At that that point the driver called 'break away; break away.' I immediately stopped the aircraft and set brake. I advised 'break set; pressure normal.' The driver informed me that another ramper failed to secure the clamps on the tow bar and once the push began the aircraft was freewheeling. I entered an ELB (Electronic Logbook) report and advised Maintenance that an inspection was needed. Maintenance visually inspected and cleared aircraft for operations. Push back continued without further incidents.

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.