Citation Excel (C560XL)
Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Time Pressure
Aircraft Equipment Problem Less Severe; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
General Evacuated; General Flight Cancelled / Delayed; General Maintenance Action
Aircraft
I was sitting in cabin discussing unrelated maintenance issue with Maintenance Control. FO (First Officer) was in cockpit preforming preflight and startup checks. As the APU was starting I smelled an electrical odor and asked my FO if he smelled it. I then looked up and saw smoke coming from above and below instrument panel. Told him to shut down and get out. Aircraft shutdown per QRH memory items and evacuated. Smoke began to dissipate immediately after power removed. Confirmed no visible fire. Battery disconnected and aircraft secured. Avionics bay opened and small amount of smoke vented no visible fire. Aircraft secured. Notified Flight Control; Maintenance Control and Assistant Chief Pilot. No passengers were on board. No injuries to crew. No visible damage to aircraft.Suggestions: Unknown without defined cause.
Upon completion of exterior preflight. I followed procedure to power up the airplane. Upon putting the battery switch in the on position a faint electrical smell was noticed which is normal in this airplane. The APU was started and its generator engaged. Smoke began pouring out from both the top and bottom of the avionics panel with a strong electrical smell. The smoke appeared to be from a possible electrical fire so procedure (per QRH and memory items) was followed to immediately power down and evacuate the airplane. The smoke ceased when power was removed from the aircraft and a strong smell of burning electronics noted in the cockpit and in the forward avionics bay doors. We secured the aircraft and disconnected the battery following successful deplaning. Suggestions: Unknown until the cause of the failure can be determined.
C560XL flight crew reported a fumes event during pre-flight which progressed to smoke pouring from the avionics panel resulting in passengers being deplaned.