Warning thresholds
If the torque at the nose wheel exceeds 70% of the current limit value,
the yellow warning light starts to flash. At the same time a buzzer
sounds at regular intervals.
If the torque steer forces are reduced, the warning lamp goes out and
the buzzer stops sounding.
If the torque at the nose wheel exceeds the current limit value
(overtorque), the red alarm lamp illuminates as well as the yellow
warning lamp. At the same time a buzzer sounds continuously.
This alarm continues once the aircraft has been set down. The alarm
can be reset only at the key-operated switch. Switching the ignition
on and off does not cancel the alarm.
The operator must establish and document suitable measures
to be followed if overtorque occurs (red alarm lamp), in
accordance with SAE ARP 5285, and these must be put into
action.
We recommend that these measures be provided to the
operator/driver in the form of work instructions inside the AST.
If a fault occurs on the system, measurement is cancelled and the
event is signalled on the TDM in the form of a message.
Important note:
The GOTIS system only performs monitoring of the torque steer
force, corresponding to the role of the shear pin on a towbar. The
steering angle between the aircraft tractor and the aircraft is not
monitored.
Adherence to the steering angles permitted for different aircraft is the
responsibility of the tractor driver.
BA part 1/0
GOTIS AST-2 R
Page 2
Fig. 2
Description of GOTIS
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