An air safety investigation into a Qantas flight that had a “fuel event” while flying from Perth to Sydney on 11 August is looking closely at pilot fatigue as a factor.
In its preliminary report the Australian Transport Safety Bureau says the pilots of the Boeing 737-400 overlooked a vital switch that would have transferred fuel from a central tank to the jet’s two main tanks in each side of the wing. When 51 minutes from Sydney they corrected the error after a warning light came on at a time when both of the main tanks were almost empty and the central tank untouched.
This initial report shows that both pilots had flown a busy “rotation” of services in the four days before the transcontinental flight, all of them on more advanced Boeing 737-800s which use a different set of instrument displays for the monitoring of fuel burn and its transfer between tanks.
The final ATSB report which may take months to complete is expected to touch on some sensitive issues for airlines.
These include crew rest periods and duty scheduling, and the use of one set of pilots for different versions of the same jet, in this case what are known as classic or older 737s such as the 737-400 and newer or NG (next generation) 737s including the 737-800 where there are subtle yet significant differences in instrumentation.
“Common rating” pilots saves money. But the risk of turning a transcontinental flight into a glider over Swan Hill might cost much more.
There is nothing in the ATSB preliminary report to suggest events would have reached that stage on this flight, or that passenger safety was seriously threatened, but if the issues were not of real concern they would not be the subject of this continuing inquiry.
In this “event” the ATSB will also examine any airworthiness issues which may arise including the manufacturer limits on how much fuel must remain in the main wing tanks and central auxiliary tank at various loadings.