Date: 201708
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: Regional Jet 200 ER/LR (CRJ200)
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Taxi
ATC / advisory: Ramp ZZZ
Aircraft component: APU
Component problem: Failed
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Anomaly: Aircraft Equipment Problem Less Severe; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Detector: Person Flight Crew; Person Ground Personnel
When detected: Taxi
Result: Aircraft Aircraft Damaged; General Flight Cancelled / Delayed
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: About to push out of gate and then I smelt smoke in the flight deck and asked the FO (first officer) if he smelled anything as well and he said yes and then the aircraft had a power surge. At the time I thought the APU gen just went offline but then the whole aircraft shook and APU RPM went from 100 to 0 in a matter of seconds; less than 2. At this time the FO called the FA (Flight Attendant) to ask if there was any smoke and she said no not at this time. At the same time; ramp told us that we were on fire and [there was] smoke coming from the APU and I asked the ramp to repeat himself. He said well it's not on fire anymore but a lot of smoke coming out; still the FO called the FA again and asked if there was any smoke in the cabin she said yes there is now some smoke and a few passengers said there was a lot of smoke on the right side outside of the aircraft. At this time I'm looking up the ramp frequency because we are on battery power and only the standby radio works. While doing so I hear in my headset another ramp person said there's still smoke coming from the APU. I called ramp and I told them we need ARRF/airport fire department to the aircraft immediately. Ramp responded with roger. I also called maintenance to tell them to get to [the gate] for APU severe failure. As I'm looking on the EICAS I'm trying to figure out what the heck is going on because there is no APU fire warning bell going off but I put it together that the APU had a severe internal breakage. I think it was a fan blade inside the APU that was loose that caused the APU to seize up which made the APU violently turn off. That was what shook the aircraft violently and the turning off of the APU is why we were on battery power but no APU fire bell I'm still scratching my head. One pilot did tell me that the APU has to be able to get power to alarm but that's what he told me. I think it still would because it's off the hot battery bus but that's for maintenance to figure out. Keep in mind this all happened in less than 60 seconds. I went outside the aircraft to go find out for myself because the aircraft reporting system is not reporting what the ramp is telling me. I went to the back of the aircraft and I saw no smoke or fire. That is when approximately 7 airport fire trucks showed up lights on police cars and fire chief cars while I was outside I talked to the fire fighters; fire chiefs; police and maintenance about what just happened. We all went to the aft bay and opened up the hatch to see if we see anything which I did not. I called dispatch; maintenance control; and the supervisor on the bridge I was then told there's a reposition flight coming from [another airport] to swap our aircraft because everyone said yeah this thing needs a full check if not a replacement of the APU. So as I talk to the first maintenance personnel I ran into I told them what happened there response oh we can just defer it I told them well you can but I will not be flying it find someone else to fly this thing the APU is destroyed. Then some senior maintenance personnel came over and said no we have to check this thing spin the blades and make sure the failure was contained.Then I went back up to the aircraft told the passengers we are going to deplane take all their belongings with them I gave a short reason why it was because our APU failed and once everyone is at the gate I will come up and tell you further details. I told the [operations agent] that we are going to deplane she said ok thanks; and helped with the deplaning process. I then wrote this failure up [and] took a picture of the write up and sent it to [Maintenance Control]. Then the chief pilot was on the bridge wanting to know info I told him and he said he'll contact dispatch to see if we can go on this aircraft for maintenance to defer it. I stopped him right in his tracks and said no they will not defer the APU if they do I'm not flying it. There was fire and smoke coming from this aircraft it needs to be fully inspected for major damage. We discussed this situation and after he was satisfied he thanked us and went on with his day and then I called dispatch back asking for another airplane. They said give them a little bit so I called back a bit later and they said there's an airplane [waiting] for us and on our way we went to finish our day with 3 legs left.




Synopsis: CRJ200 Captain reported an APU fire and shutdown just before pushback from the gate. Captain reported passengers were deplaned and aircraft was taken out of service.