Originally Posted by
framer
I’m not making comment on how this was handled one way or the other, but I do think that fuel imbalances and leak identification on the 737 is something that is more difficult than most people assume. I’m not sure why this is the case, I have experienced confusion when trying to determine if we have a leak and my takeaway is that the pilots have to be very very diligent and methodical in stepping through the checklists and that the (totaliser fuel + remaining fuel) calculation is rarely going to be perfect, two or three hundred kg’s is to be expected. I take a ‘there but for the grace of God…’ approach to it.
Does anyone know if there was visible moisture/ precipitation at the field on the day?
I'd have to agree there with that in regard to a number of aircraft types. I think you have to really take time to identify a fuel leak unless it's brutally obvious, like fuel streaming out of the wing. You need to know your fuel system inaccuracies before the event, then see repeated corrected imbalances or signs that a large imbalance is occurring. Just stopping flow from the tank may not show a leak in the system from the tank to engine, so the fuel could be leaking from a point between the tank and engine. Then there is the differences between totalizers and actual indications, vs a lot of factors that make it very difficult to detect a small leak.
If no obvious leak, correct the imbalance, even if it's not safety related it will affect efficiency of operation. Then if it goes out of balance again really look at the numbers and the trend, follow the QRH advice and so on.
Reading the pilot experience section of the report, it appears that the First Officer had "around 1800hrs of total flying experience" and only held a CPL Licence.
I wonder if a more experienced First Officer who had previous experience flying narrow body jets for other airlines would have questioned the decision to blindly follow the engineers instructions rather than use their own checklist. Or would maybe have thought to scan the overhead panel after a maintenance procedure was completed to ensure that all the switches were where they should be. I know what kind of FO I would prefer in the cockpit in that situation.
Low time pilots if trained correctly are usually better at following SOPs, and therefor checklists, as they don't have experience as such to fall back on. If low timers are not following their failure management routines properly then that smells of systemic issues in training.