The Airbus A340-300 was on a flight from Shanghai (Pudong
International Airport) to Sydney (Kingsford-Smith) Airport. The
co-pilot was the handling pilot. During the flight, the crew
observed there was low fluid quantity in the Green hydraulic system
and they witched off the Green system engine-driven and electric
pumps. As the Airbus was manoeuvred for the approach to runway 16R
at Sydney, the crew extended the landing gear by gravity extension.
The crew reported that the landing was normal, and that engines
number 2 and 3 thrust reverses were deployed after touchdown.
Directional control was maintained with rudder, however, as the
aircraft was decelerated through approximately 30 kts, directional
control was suddenly lost. He applied full manual braking, but the
aircraft was yawed rapidly to the right, and came to rest on a
heading of approximately 280T, which was about 120 degrees off
runway heading. The main landing gear wheels remained on the sealed
surface of the runway, however, the nose wheels were on the grasses
area adjacent to the runway, approximately 16 m beyond the runway
edge. None of the passengers or crew was injured.
The investigation revealed that a crack in the number one engine
EDP case led to the loss of the Green system hydraulic fluid.
However, this was not a factor contributing to the final loss of
directional control of the aircraft. The flight data revealed that
the engine number one thrust lever was inadvertently advanced after
the pilot in command took control of the aircraft. The rapid manner
in which it was advanced , suggests there may have been some
confusion between the pilot in command and the co-pilot at the time
of the takeover of control. In the process of taking control, it is
likely that the pilot in command placed his right hand on the
thrust levers before the co-pilot could completely relinquish his
control of them, and that the subsequent advancement of thrust
lever number one was a result of this confusion. As the aircraft
began to veer rapidly tot eh right, the crew's attention was
substantially diverted by the unexpected and sudden loss of control
of the aircraft. with their attention so diverted, none of the crew
would have been initially aware of the engine number one thrust
lever position, and that the engine was delivering substantial
asymmetric thrust that contributed to the loss of control.