Dash 8 Series Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Confusion
Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Flight Crew Took Evasive Action; General Evacuated
Aircraft
With passengers boarded and doors closed; we started the number two (right) engine and determined it was a good start. I then started the number one (left) engine. It was during this start up; as the first officer turned on the bleed as directed in the checklist; I noticed a faint haze of sorts coming from the air vents. At first I thought it may have just been condensation; but after a successful start on engine one; the cockpit quickly began to fill with smoke. It did not smell like an electrical burn; but did have a distinct burning smell. Myself and the first officer agreed it was smoke and I immediately shut down both engines. I opened the cockpit door; informed the flight attendant to open the main passenger door and executed an expedited deplaning/evacuation. The first officer reiterated it was not an emergency to the flight attendant as I made an announcement over the Public Address system for all passengers to quickly deplane the aircraft through the main passenger door only. All passengers quickly deplaned through the main door. Note; no emergency exits were used. I completed a shutdown of the entire aircraft and then contacted dispatch and maintenance. Maintenance personnel boarded the aircraft within minutes. While I was on board and all passengers had left; maintenance started the number two engine and it produced smoke once again essentially replicating the event we had just experienced. Myself and the crew then left the aircraft. I debriefed with the first officer and flight attendant and commended them on a job well done.
Dash 8 Captain reported ordering all passengers to exit through the main cabin door after noticing smoke in the aircraft following engine start.