Date: 201910
Aircraft: B737 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Taxi
Aircraft component: Powerplant Fuel System
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Human factors: Situational Awareness; Time Pressure; Troubleshooting; Workload
Anomaly: Aircraft Equipment Problem Critical; Ground Event / Encounter Other / Unknown
Detector: Person Air Traffic Control; Person Flight Crew; Person Other Person
When detected: Taxi
Result: Air Traffic Control Provided Assistance; Flight Crew Requested ATC Assistance / Clarification; General Evacuated; General Maintenance Action
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: We taxied out from gate on time on a single engine (right engine). Taxi instructions from Ground Control were B; D; at V follow an Airbus; and monitor Tower. After passing V; Tower called us and said that the Company B767 behind us was noticing a fluid leaking out of the right wing. At the time; there was no other information. It seems as though they were still on Ground Control; because I could not hear the communication relay from the B767. I asked Tower if they could be more specific as to where the leak was coming from. They said that it looked like outboard of the last flap; near the wing tip. They said that it appeared to be leaking quite steadily. We asked to move from D to the De-ice pad area and were instructed to proceed through the pad to PA and hold short of CC. At that time we secured both engines and turned off all fuel pumps. I coordinated with the Flight Attendants; and made them aware that an evacuation may be possible. I made a passenger PA and informed them of the situation; stating that at that time we were in an information gathering mode and to standby for further instructions. The FO (First Officer) was able to ascertain that after shutting down the engines and fuel pumps; the leak appeared to slow. At that time; Airport Operations was at the aircraft and confirmed that it was most likely a fuel leak; and although slow; was still leaking. Tower advised that [Airport Rescue and Firefighting] had been called and were enroute. I called Station Operations and informed them of the issue. I asked to have air stairs and buses available in the event an evacuation was needed. We also called Maintenance and informed them of the issue as well as the current fuel load. The left tank had 8;530 lbs. and the right had 8;610 lbs. The center tank had 14;980 lbs. They were sending a team out to investigate. I kept the passengers informed during this time about what to expect with [Airport Rescue and Firefighting] coming. I also reassured them that although we had a serious situation; we were not in any imminent danger. [Airport Rescue and Firefighting] positioned themselves strategically around the aircraft with an air stair available about 10 ft. from door 1L. Tech Operations arrived and conferred with Airport Operations; [Airport Rescue and Firefighting] and us. It was determined that the best course of action would be to de-plane the aircraft at its current location. At that time buses had arrived and the air stairs pulled up. I advised the Flight Attendants and then made a PA. I had conferred with Tech Operations that the passenger would be able to bring their personal belongings given the fact that this was not an emergency evacuation. We had to wait a few minutes; I was told because Customs had to be made aware of the situation. The door was opened by [Airport Rescue and Firefighting] personnel and the passengers deplaned in an orderly and safe manner. I had the FO assist while I was conferring again with Tech Operations about how to handle the plane after the de-planing process. I was told that they would be taking control of the plane from me and handling it from there. I then assisted in the process until all souls were off of the aircraft. I did a final walk through and exited to the bus waiting for the crew.I am not sure whether or not to call our de-planing an evacuation. I filled out a [report] and did reference it as a precautionary evacuation. If I mis-characterized it I apologize. In addition; an emergency was never officially declared because Tower had already called [Airport Rescue and Firefighting] to the aircraft; and the relevant information was relayed.




Synopsis: B737 Captain reported being notified by a following aircraft that fluid was steaming from the wing resulting in an evacuation.