EMB ERJ 170/175 ER/LR
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Communication Breakdown
Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Other / Unknown
Flight Crew Regained Aircraft Control
Weather; Procedure; Airport; Human Factors
As we approached the gate in ZZZ; the Ground Crew member was using non-lighted wands during dusk hours at a shaded gate making it difficult to see his hand signals. Although not required during dusk; it was difficult to see and understand his hand signals. Once we came to a stop I observed what appeared to be a chocks in signal. I released the park brake to cool them off as we were on a quick turn as stated in the SOPM (Standard Operating Procedures Manual); and then we began a slow roll back as the aircraft was not in fact; chocked in. We rolled back about a ft. or two before I realized we weren't chocked in. I had to restart an engine to re-position the aircraft to the correct parking spot. The Ground Crew member and I debriefed the situation and both agreed that lighted wands may prevent the event in the future.No lighted wands made it difficult to understand the ground crew's hand signals. My interpretation of the aircraft being chock in. At the time of dusk in shaded areas such as Gate XX in ZZZ; lighted wands would increase the margin of safety.
EMB-170 Captain reported uncommanded aircraft movement after misinterpreting Marshaller's instructions.