Date: 202112
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: Embraer Undifferentiated or Other Model
Operator: Air Carrier
Flight plan: IFR
Mission: Passenger
Flight phase: Taxi
ATC / advisory: Ramp ZZZ
Reporter organization: Air Carrier
Reporter function: Pilot Flying; First Officer
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Human factors: Communication Breakdown; Situational Awareness
Second reporter function: Pilot Not Flying; Captain
Anomaly: Conflict Ground Conflict; Critical; Ground Event / Encounter Other / Unknown
Detector: Person Ground Personnel
When detected: Taxi
Contributing factors: Human Factors; Procedure; Weather
Primary problem: Human Factors

Narrative: Aircraft X from ZZZ-ZZZ1 Date required deicing. After a two-engine turn from the gate; the aircraft proceeded to the deice pad. The aircraft was then configured for de-icing; type 1 fullbody. The ramp crew was contacted. We informed them the aircraft was ready; and they sprayed the aircraft. When complete; the ramp crew called on frequency and informed us of the time; type of fluid; clear of contaminates; and ready for departure. We then ran a reconfiguration checklist which requires all trims to be fully tested. This procedure took approximately 1 to 2 minutes. We also started a timer for the engine bleed and packs. After the trims were tested; we switched frequency to see if a new ATIS was available.After we received a ready for departure clearance from the ramp crew; the aircraft did not start rolling for a minimum of 5 minutes. Before we moved; I cleared the right side of the aircraft and Captain cleared the left. The area was clear of any obstructions and looked safe to taxi. There was no way for us to know what was behind our wings or tail. The aircraft flew to ZZZ1 without any further incident. I was unaware of anything dangerous that happened until I received a phone call from the Chief Pilot Office. I was informed that the ice truck returned to the aircraft and a ramp member was almost struck by the tail of the aircraft while deicing the aircraft for a second time. I believe the ramp crew noticed additional ice on the aircraft and attempted to clear it without any communication with the crew.I believe this situation could be avoided in the future two different ways: by having an additional ramp member holding an 'X' symbol while we deice; and double checking that all contaminants are in-fact removed from the aircraft before a radio call is made.


Second narrative: It was the first flight of the day and there was heavy snow from the night on the airplane. The day started as normal with a two engine power out at ZZZ to the de ice area after we completed the after start checklist. We configured the aircraft according to the checklist but left both engines running and advised the de ice crew; both engines running and APU off. All other checklist items completed. At the completion of de icing type one; the de ice truck was out of sight. We received the time started which I wrote down of XA58 local; fluid type; and tactical check complete; and the aircraft is free of contamination. At that point; we ran all the trims up and down; waited one minute for the bleeds; and advised the FA (Flight Attendant) that de icing was complete to complete the de ice checklist. Before taxi; we switched frequencies to verify ATIS report. I specifically remember clearing the area. I always verbalize my clear left as I look left and FO (First Officer) cleared right. We called Ground and asked for clearance to taxi. We taxied for the remaining 3 minutes (before starting the packs after de icing) to Runway XX for departure. At no point did we receive any indication from Tower or other frequencies anything was wrong. I was later advised by the Chief Pilot Office of an event where we almost hit a de ice truck that was reportedly re inspecting the potential of ice crystals on the tail. There was clearly a miscommunication between the de ice crew and us in the cockpit. Due to the de ice trucks communication with us in regards to the time; fluid type; tactile check and clean airplane; I chose to continue with the checklist and complete the taxi to the runway. From the power out of the gate; to departing the airport; there was not any indication that anything was wrong or not standard at any time. Neither I nor the First Officer felt rushed at any point. After receiving the final communication from the de ice truck; we continued with normal procedures to the runway which we later were told caused the airplane to move in close proximity to the de Ice truck. The procedures for de icing seem sound and I have never had a communication issue with the de ice truck. However; it would be helpful to always have the truck pull in front of the aircraft before making the final call to the crew; so that the crews can see that the truck is physically out of the way and not in the rear of the plane where the pilots can't see.


Synopsis: Flight Crew reported they were advised after the flight that they almost collided with a deicing truck when they taxied from deicing while the truck was still inspecting the aircraft.