Date: 202201
Location: DEN.Airport, CO
Aircraft: Widebody; Low Wing; 2 Turbojet Eng
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Cargo / Freight / Delivery
Flight phase: Taxi
ATC / advisory: Ground DEN
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Human factors: Situational Awareness
Second reporter function: First Officer; Pilot Not Flying
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Loss Of Aircraft Control; Ground Event / Encounter Weather / Turbulence
Detector: Person Flight Crew
When detected: Taxi
Result: Flight Crew Took Evasive Action; Flight Crew Regained Aircraft Control; Flight Crew Returned To Gate; Flight Crew Overcame Equipment Problem; Flight Crew Inflight Shutdown; Flight Crew Became Reoriented
Contributing factors: Human Factors; Weather; Airport
Primary problem: Weather

Narrative: While turning on to [taxiway] SC the aircraft started to slide. I placed the throttles in reverse idle to make sure I did not depart the taxiway that was covered in ice and snow. I was at my slowest possible but wanted to make sure that I had reverse thrust available if I continued to slide down SC that has a steep decline. The throttles did not come out of reverse idle but the right engine flamed out. We attempted to restart the right engine but approached a hot start approximately 547 degrees. We stopped the right engine start procedure and stopped taxiing because the taxiway condition was nil and could not get any traction with the nose wheel or differential breaking for the turn. Requested snow crews plow the ramp and tug crew pull us into the gate. We were towed without incident after the snow crews plowed the ramp.


Second narrative: While the Captain was taxing south on taxiway M; approaching SC. We were at a crawl and I could feel the airplane sliding to the right. I asked the Captain 'Is the airplane sliding?' The Captain acknowledged and stated that he was going to unlock the thrust reversers into idle. As soon as the aircraft stopped sliding; the Captain announced he was stowing the reversers. We successfully made the turn onto SC and slowly began the downhill descent to the ramp. The Captain reported that the right engine had flamed out during the thrust reverser deployment. I saw no abnormal EICAS messages other than the normal right engine shutdown messages and no limits had been exceeded. The Captain requested an attempt to restart the right engine. The start attempt was aborted after EGT approached red line and recorded a max EGT of 547 was reached after fuel cutoff. While trying to enter the ramp from SC; there was visible snow on the ramp where we needed to enter and crews could be seen beginning to actively clear the ramp. The aircraft again began to slide right. The Captain brought the aircraft to a stop and we agreed that a tow-in would be needed.


Synopsis: Flight crew reported sliding while taxiing due to snow and had to be towed back to the gate.