Air carrier flight crew reported while boarding the aircraft they experienced a burning smell and smoke resulting in the Captain evacuating the crew and getting ARFF assistance.
Synopsis
Air carrier flight crew reported while boarding the aircraft they experienced a burning smell and smoke resulting in the Captain evacuating the crew and getting ARFF assistance.
Narrative
After boarding the aircraft in BNA; I went to the aft galley to brief the FAs (Flight Attendants). During the briefing; we began to notice a slight burning smell; which was quickly followed by white/gray smoke coming from the air conditioning system. The smoke became so thick that we could not see the front of the aircraft. I instructed the FAs to get off the aircraft; and I ran to the flight deck at which time I shut down the packs; bleeds; and APU. I evacuated my crew to the top of the jetbridge; as the smoke was acrid and causing irritation while breathing it. It also filled the jetbridge. I asked the gate agent to contact ARFF (Airport Rescue and Firefighting) to have a fire truck standing by; because at this time; the source of the smoke was not certain. We also contacted Maintenance Control to report the issue; since we did not have the ability to send an ELB (Electronic Log Book). Maintenance responded and after inspecting the bleed system; found large amounts of deicing fluid that had contaminated the air conditioning system. It appears the ground crew sprayed fluid into the APU inlet while deicing the aircraft at the gate. Maintenance did a smoke inspection in which they looked at several other systems; and confirmed that the deicing fluid was the source of the smoke. We released ARFF when we were confident we knew the source of the smoke. They cleaned what they could; ran ground air to clean the air system; and dispatched the aircraft. The FAs used the deodorizers to aid in clearing the cabin of the slight burning smell. Passengers were briefed as to what had occurred; so that they would not become nervous from smelling the residual burning scent. We dispatched and flew to ZZZ with no further issues. All systems operated normally.
Second reporter narrative
Prior to the flight crew entering the aircraft. Maintenance had repositioned the aircraft to the gate and had the APU and packs running to warm the aircraft. Ramp had not plugged in any GPU or PC air. We arrived to the aircraft and met the flight attendants on board. We began a normal setup and the Captain went back to brief the FAs (Flight Attendants). I proceeded to go out for a walk around; and before I exited the jet bridge; everyone ran out of the aircraft as it was filled with smoke. We didn't know at the time but the ramp was actively de-icing the aircraft as we boarded; while Maintenance had the APU running with the packs and bleeds configured accordingly. The Captain acted promptly to turn the packs and bleed sources off and turn off the APU and secure the aircraft appropriately. She then made all the necessary calls and made sure the crew and everyone was In a safe place. Maintenance ran all checks and cleared everything out as appropriate; we later departed delayed with no further problems.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.