B737 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 163
Distraction; Human-Machine Interface; Training / Qualification
Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Other / Unknown
Flight Crew Became Reoriented
Human Factors
After push back and tow out I thought the parking brake was set; but Park Brake Light was not on. I was distracted by an extreme amount of loud feedback/engine noise over the headset and was concentrating on listening to the tow truck driver instructions.
B737 Captain reported he attempted to set the parking brake after push back but did not notice the Parking Brake Light was not on after the attempt.