B737-700
Maintenance Airframe; Maintenance Powerplant
Situational Awareness; Training / Qualification
Deviation / Discrepancy - Procedural Other / Unknown; Ground Event / Encounter Other / Unknown
Aircraft Aircraft Damaged; General Maintenance Action
Equipment / Tooling; Human Factors; Procedure
I drove a tug out onto the ramp to pull and refuel carts. I saw a heat cart on fire next to the left side of the aircraft and drove towards it. I called on the radio for somebody to call the fire department that there is a heat cart on fire. When I got to the scene I saw a work truck with a fuel cart attached to the vehicle next to the burning heat cart. I saw [an employee] using a fire extinguisher to put out the fire. Our shift manager was on the radio saying get away from the fire. I was going to drive away with the work truck that had the fuel cart attached to it but the fuel nozzle was still attached to the heat cart that was on fire. I was afraid the fuel nozzle was still pumping fuel. I saw [someone] walk to us with a fire extinguisher and began to put out the fire. Then I saw [the first employee] hit the fuel nozzle with the fire extinguisher and the fuel nozzle detached from the aircraft and when I saw the fuel nozzle was not pumping fuel; I then got into the work truck and drove away with the fuel cart attached to a safe distance. I saw the fire department arrive and extinguish the fire.[We need] better maintenance of heat carts and better fueling procedures.
Mechanic witnessed a heat cart catch on fire while still next to an aircraft. Nearby ground personnel and firefighters were able to respond quickly to extinguish the fire.