Emb-190 flight crew reported they experienced auxiliary power unit failure during pushback.

Narrative:

We were pushing from gate and shortly after the captain asked me to start the number 1 engine we heard a loud explosion and the aircraft went electrically dark. Power came back online almost immediately most likely as a result of the engine driven generation coming online. As we were attempting to assess the cause of the explosion; rampers began yelling that they saw flames and smoke coming from the tail of the aircraft. While the captain was trying gather information from the rampers; I referenced the qrc for APU fire and found the appropriate page in my QRH. The information we were gathering from outside the aircraft made it sound like there was no present fire; but they did tell us there were parts of the APU on the ground. The APU had automatically shut itself down (or failed) and there were no fire indications displayed in the cockpit. The captain spoke with our number 2 flight attendant and assessed no flames; fumes or smoke in the cabin. I quickly asked ramp if we could take gate as it was unoccupied and we are pointed directly at it. I then needed to confirm the request with ground and told them we would need emergency personnel and firetrucks to assess the exterior of the aircraft. Emergency responders were quick to arrive and report no flames or smoke outside the aircraft. We arrived safely at gate and deplaned.

Original NASA ASRS Text

Title: EMB-190 flight crew reported they experienced Auxiliary Power Unit failure during pushback.

Narrative: We were pushing from gate and shortly after the Captain asked me to start the Number 1 engine we heard a loud explosion and the aircraft went electrically dark. Power came back online almost immediately most likely as a result of the engine driven generation coming online. As we were attempting to assess the cause of the explosion; rampers began yelling that they saw flames and smoke coming from the tail of the aircraft. While the Captain was trying gather information from the rampers; I referenced the QRC for APU fire and found the appropriate page in my QRH. The information we were gathering from outside the aircraft made it sound like there was no present fire; but they did tell us there were parts of the APU on the ground. The APU had automatically shut itself down (or failed) and there were no fire indications displayed in the cockpit. The Captain spoke with our Number 2 Flight Attendant and assessed no flames; fumes or smoke in the cabin. I quickly asked ramp if we could take gate as it was unoccupied and we are pointed directly at it. I then needed to confirm the request with ground and told them we would need emergency personnel and firetrucks to assess the exterior of the aircraft. Emergency responders were quick to arrive and report no flames or smoke outside the aircraft. We arrived safely at gate and deplaned.

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.

Attributes
ACN	1702432
Time
Date	201911
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Aircraft 1
Make Model Name	EMB ERJ 190/195 ER/LR
Operating Under FAR Part	Part 121
Flight Phase	Taxi
Flight Plan	IFR
Component
Aircraft Component	APU
Person 1
Function	Pilot Not Flying First Officer
Qualification	Flight Crew Instrument Flight Crew Air Transport Pilot (ATP) Flight Crew Multiengine
Person 2
Function	Pilot Flying Captain
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument Flight Crew Multiengine
Events
Anomaly	Aircraft Equipment Problem Critical Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor