B737 Undifferentiated or Other Model
Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Flight Crew Last 90 Days 198; Flight Crew Type 868
Communication Breakdown
Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Other / Unknown
Flight Crew Overcame Equipment Problem; Flight Crew Took Evasive Action
Human Factors; Procedure
During push things proceeding normally. After the aircraft was pushed aft; it was pulled forward slightly then stopped. The wing walker to my left (abeam) signaled an X with the wands; but the tug crew never said to set brakes. There was a hot mic; from the tug; so it was clear nothing was said. I was very focused on the marshaller to the left; as this seemed nonstandard. The aircraft smoothly; slowly started moving forward. I asked on the interphone if he wanted me to set the brakes. There was no response. I didn't immediately set the brakes because I was not sure if it was the tug pulling us forward. The marshaller to my left then pointed at me; and I was sufficiently concerned that this was not the tug pulling me forward; so I slowly applied the brakes and brought the aircraft to a stop; simultaneously asking if he wanted me to set the brakes. This time he (tug operator) answered set brakes. The aircraft was not moving then. Subsequent actions were to SOP.This was frightening in the opportunity for injury. An incident was prevented due to two things; something triggered my mind that this was nonstandard so I was hyper-focused on the wing walker that was abeam. The second was her attention and gaining my attention as the aircraft started rolling. My First Officer was very new and focused on the engine start and not aware until after. But had he had a question or issue drawing me inside; I would not have seen the wing walker point to me and there could have been tug contact or injury.All totaled; the aircraft probably rolled less than 3 ft.; but that is not the point. There was no communication and an opportunity for a worse outcome.
B737 Captain reported communication breakdown between flight crew and pushback crew during pushback.