Regional Jet 900 (CRJ900)
Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Ground Event / Encounter Loss Of Aircraft Control
Air Traffic Control Provided Assistance; Flight Crew Regained Aircraft Control; Flight Crew Requested ATC Assistance / Clarification; General Maintenance Action
Airport; Environment - Non Weather Related; Weather
[As we were taxiing to the runway] ground control asked us for a braking action report which we reported as good. As we taxied closer to the runway they informed us of a wheels-up time and to taxi into the runup pad. We were running on both engines and taxiing at around 10 knots. When we reached the runup pad; I noticed that it looked clear and free of ice and snow. I slowed the airplane to around 5 knots as I made the right turn into the runup pad and the airplane began to slip. I applied brakes and pumped them in an effort to get the airplane to stop but it would not stop. The aircraft skidded to the left and all of my attempts to stop it did not work. The aircraft skidded uncontrollably for about 5-6 seconds. We eventually came to a stop on a patch of snow; it was a very gentle stop. I had initially thought that we had exited the pavement and suspected damage to the aircraft after coming close to a taxiway edge light. We contacted ATC and told them of our situation and that we would need assistance. I then talked to our Dispatcher and let them know what was going on. I also talked to the flight attendants to make sure they and the passengers were ok. I made an announcement to the passengers telling them that we had slipped and had come to a stop on snow and that we were standing by for ground personnel to inspect the aircraft. When airport operations arrived at the airplane; they inspected and told us that we were still on hard concrete and still far from the grass and that we did not damage any taxiway edge lights. They told us that they would de-ice the ramp and plow the area in front of us and that we would be in good shape to taxi out. The FO (First Officer) and I concluded that it would be a better idea to be towed out from where we were because we didn't want to risk slipping again. The ramp did have a negative gradient and we were about 3-5 feet from the grass; I did not want to take a chance. We also noticed the airport operations vehicles had a hard time maneuvering around the ramp which gave us more reason to believe that taxiing out on aircraft power was not a good idea. Our Dispatcher and Duty Pilot agreed with us; so we coordinated with operations and maintenance to be towed out. I made a second PA to the passengers and told them that we were standing by for a tow vehicle to move us from the spot. When maintenance arrived at the aircraft; they did another inspection and confirmed what airport operations had told us; that we were still on hard pavement and there was no damage to the aircraft or airport property. They proceeded to tow us out. I made an entry into the aircraft logbook and they signed it off. After coordinating with maintenance; our Dispatcher; and Duty Pilot; we all came to the mutual agreement that the aircraft was safe and legal to operate the flight. I made sure that the FO and the flight attendants were doing ok and that they were still fit for duty. They all said yes; and we continued the flight with no further issues. The cause of this incident was black ice on the run-up pad. We could not tell that there was any ice since the pad looked as clean and clear as the taxiways. Furthermore; the current ATIS at the time had reported that the taxiways had been recently de-iced. Because of this; I had no reason to believe that taxiing into the run-up pad would result in slippery conditions. After the incident it dawned on me that I never thought about using thrust reversers to try to stop the airplane from slipping. However; I'm not sure that this would have helped since the aircraft was skidding to the left and was not slipping straight forward.
CRJ-900 Captain reported losing control of the aircraft after encountering black ice on a taxiway.