Fractional flight crew reported the cabin filled with smoke from a faulty APU prior to takeoff.

Attributes
ACN	1581911
Time
Date	201809
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Light Transport Low Wing 2 Turbojet Eng
Operating Under FAR Part	Part 91
Flight Phase	Taxi
Flight Plan	IFR
Component
Aircraft Component	APU
Person 1
Function	Pilot Flying Captain
Qualification	Flight Crew Multiengine Flight Crew Instrument Flight Crew Air Transport Pilot (ATP)
Person 2
Function	Pilot Not Flying Captain
Qualification	Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument
Experience	Flight Crew Last 90 Days 75 Flight Crew Total 9000 Flight Crew Type 2000
Events
Anomaly	Aircraft Equipment Problem Less Severe Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor

Narrative:

I was co-captain sic (second in command) in the right seat. During taxi out for departure runway xxr at ZZZ; one of the passengers commented about it being warm in the cabin and asked if we could cool it down. I started the APU and turned the bleed air on hi. A few minutes later we were cleared to 'line up and wait' runway xxr. About that time I smelled something abnormal. Not like electrical or plastic smoke but oily; metallic. I turned around and observed smoke filling the cabin. [Advised ATC] and told tower we had smoke in the cabin and needed to evacuate the aircraft. I shut down the APU; escorted the passengers off the aircraft and eventually back to the FBO. The PIC (pilot in command) completed the engine shutdown and emergency evacuation checklist and remained with the aircraft. The arff (aircraft rescue and firefighting) crew confirmed no fire but residual smoke in the cabin and aft fuselage APU compartment. Recovery flight for the passengers was put in motion.

Original NASA ASRS Text

Title: Fractional flight crew reported the cabin filled with smoke from a faulty APU prior to takeoff.

Narrative: I was Co-Captain SIC (Second in Command) in the right seat. During taxi out for departure Runway XXR at ZZZ; one of the passengers commented about it being warm in the cabin and asked if we could cool it down. I started the APU and turned the bleed air on HI. A few minutes later we were cleared to 'line up and wait' Runway XXR. About that time I smelled something abnormal. Not like electrical or plastic smoke but oily; metallic. I turned around and observed smoke filling the cabin. [Advised ATC] and told Tower we had smoke in the cabin and needed to evacuate the aircraft. I shut down the APU; escorted the passengers off the aircraft and eventually back to the FBO. The PIC (Pilot in Command) completed the engine shutdown and emergency evacuation checklist and remained with the aircraft. The ARFF (Aircraft Rescue and Firefighting) crew confirmed no fire but residual smoke in the cabin and aft fuselage APU compartment. Recovery flight for the passengers was put in motion.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.