Date: 201906
Local time of day: 1801-2400
Location: ORD.Airport, IL
Flight conditions: VMC
Weather elements / visibility: Rain
Light: Daylight
Aircraft: B777 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Taxi
ATC / advisory: Ground ORD
Second aircraft: B777 Undifferentiated or Other Model
Aircraft component: Engine
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Human factors: Confusion; Situational Awareness
Second reporter function: First Officer
Anomaly: Aircraft Equipment Problem Less Severe; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Detector: Person Flight Crew; Person Observer
When detected: Taxi
Result: Air Traffic Control Provided Assistance; Flight Crew Overcame Equipment Problem; Flight Crew Returned To Gate; General Flight Cancelled / Delayed; General Maintenance Action
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: We were parked on Taxiway R and holding short of Taxiway G due to weather ground stop. We started the APU and requested to shutdown both engines; request was granted. Within 10-15 minutes; ATC advised to start engines and be ready for departure on Runway 9R shortly; we accomplished before pushback checklist and proceeded to start both engines. Both starts appeared normal until aircraft behind us announced that there was fire coming out of tailpipe on our left engine; followed by confirmation from ATC Ground Controller. We proceeded to shut down the left engine; there were no cockpit caution or warning indication and engine instrument appeared normal. Fire rescue arrived almost immediately and advised there was no fire or smoke after engine shutdown. We discussed possible evacuation if fire persisted; also accomplished tailpipe fire checklist.We determine since the threat of fire and smoke no longer existed; to request a new gate from operations. We were given [a] gate and requested ATC clearance to proceed to [the gate]. The fire rescue was requested to escort us to the gate.Flight attendants and passengers were informed accordingly; shortly after parking at the gate; Agent Supervisor announce a new gate for departure and another aircraft would be available. I walked towards back of the aircraft to answer any questions or concerns; everyone seemed fine. We complied with all applicable checklist and resume to do flight plan preparations for the next aircraft to Munich. Rest of trip was uneventful.


Second narrative: We pushed back tail north from [the gate;] taxied and [turned] right turn on R. Three RJs were between Flight XXX and my aircraft. Most of the aircraft had shut down one or two engines. There was a long delay for departures to the East on 9R due to weather east of ORD. When Flight XXX was given clearance to taxi they let ground control know they would be starting their engine. When they started their left engine their aircraft was on R taxiway near J; we could not see the engine from our position. We did see a large bright red flame that extended 20-30 feet long and 10-15 feet high. About 3 seconds after we saw the fire we heard another aircraft tell Flight XXX their left engine was on fire. It took several more seconds before the fire was extinguished. After that the RJ aircraft verified the fire was out since we could not see the engine from our position. The fire trucks arrived minutes later and confirmed fire was out.


Synopsis: Captain in affected aircraft and First Officer in observing aircraft reported tailpipe fire during engine start on taxiway.