Date: 201911
Local time of day: 0001-0600
Location: ZZZ.Airport, US
Aircraft: B747-400
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Cargo / Freight / Delivery
Flight phase: Parked
Aircraft component: Fuel System
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Situational Awareness
Anomaly: Deviation / Discrepancy - Procedural Hazardous Material Violation; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Other / Unknown
Result: Aircraft Aircraft Damaged
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: I was deadheading from ZZZ to ZZZ1 and after arrival at the airport we were notified that our first airplane had a hydraulic issue and that we were switching airplanes. After arriving at the new airplane Maintenance was working a fuel issue. To remain clear of the crew and the full upper deck I and a few of the other dead headers stood outside on the stair platform given the relatively nice weather. On this flight we had a company representative from riding along going to ZZZ. While we watched Maintenance working on the fuel issue we were discussing the safety aspects of working on open fuel systems and precautions Maintenance should be taking. The subject came up that if a fuel tank is open would Maintenance have to deactivate the High Frequency radios in case ACARS attempts to utilize them on the ground or an inadvertent activation. [Supervisor] walked down to see what was transpiring by the wing where the mechanics were working. At this point we had a large high capacity fuel truck connected to the left side wing. There was a small amount of fuel on the ground from what appeared to be some fuel leaking from the wing vent. At this point the size was probably less than 1 foot in diameter and hardly a concern. We walked back upstairs to see what the latest was in terms of departure; the crew simply stated they had an issue with the fuel system; a Mechanic was in the Captain seat working the problem; so we left to remain outside and clear of the work in progress. Sometime later we noticed fuel literally pouring out of the wing vent area exact source of fuel leaking cannot be stated due to where we were standing on the air stair platform. We saw what appeared to be a long running stream approximately 20 feet wide running aft of the wing toward the tail based on the reflective surface it presented.Supervisor came back down and saw this; I told him the mechanics need to get a fire truck out there just in case the fuel ignites. He stated that was not required; I stated again; excuse me but there is a lake of fuel under the wing and it is growing. I walked down to gage the actual size of the fuel leak; noting that the length of the puddle using the relative length of the vans and vehicles to be between 80-100 feet long and approximately 20 feet wide. At this point additional Maintenance personnel are arriving with absorbent pads and oil absorbent media trying to contain the growing fuel spill. I also noticed a fuel collection tank in position under the wing near where the Mechanic was attempting to work on the fuel system. At this point with all the personnel walking around in the open fuel spill; piles of fuel soaked absorbent pads; leaking fuel from the wing; multiple vehicles with 'Spark Ignition Engines' standing around idling near the fuel spill; a large capacity fuel truck still connected to the wing; and an airplane with 107;000 kg of fuel onboard. I did the next logical thing; and removed myself from the self-immolation area. I proceeded to the cockpit and told Captain that we need to get a fire truck out here immediately with foam capability. His response was I saw what was going on; I don't think we need it. At this point clearly nobody is worried about the fact that we were sitting in the middle of a disaster waiting to happen. I did the next logical thing and removed myself from the location in case a fire or explosion were triggered. I was accompanied by 4 other crew members who too could not believe that nobody wanted to call in the fire trucks in case this situation ignited! It appears that [the] Maintenance personnel were trying to clean up the spill without drawing too much attention. As this was going on; a ZZZ truck shows up; a gentlemen gets out starts pointing; and within 2-3 minutes a fire truck with lights flashing shows up.




Synopsis: B747-400 deadheading Captain reported flight crew ignored his safety concerns regarding a fuel spill due to Maintenance work.