Commercial Fixed Wing
Communication Breakdown; Situational Awareness
Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Other / Unknown
Human Factors; Procedure
We landed in SAN and taxied to a spot on the ramp to wait for our gate to open. It took just over an hour get to our gate due to Maintenance on another airplane. We parked at [the gate] and ran the shutdown checklist. My Captain pulled up the Flight Log page; I commented that we landed with 10.3 on the fuel and got to the gate with 9.2. The jetway operator was having difficulties with the jet bridge height. As she struggled with the jet bridge (all doors still closed) I noticed the fuel gauge go from 9.2 to 9.8 then 10.0. I said to my Captain 'Oh no! The fueler is hooked up and fueling!' I quickly opened my window and shouted back to the fueler a few times while waving my arm to get his attention. To my surprise I got his attention and motioned to with my hand for him to stop. He looked confused but stopped fueling and started to disconnect.I don't know why he hooked up to the jet before the door was open. I do remember seeing the ground power cable being lowered then later raised back up while all this was going on. I've since thought that maybe the signal to the fueler that it is okay to begin fueling is if the ground power cable is hooked up to the jet. That's purely my speculation but if it is then there needs to be something better for the fuelers to determine the status of the door before hooking as many times the ground power is connected before the door is open. Visually inspecting the door would be a better method.This is the second time I've seen a fueler hook up to a closed jet in SAN.
A pilot reported the fueler began fueling the aircraft before the passengers deplaned or the jetbridge had approached the aircraft.