7.1.2 Directional
control of the ACV is to be maintained in the event of a single failure
within the primary directional control system.
7.1.3 As an alternative,
independent means of steering the ACV are to be provided in the event
of a failure of the primary system. The effectiveness of the alternative
system is to be demonstrated during trials.
7.1.4 Where air
rudders are used for steering the ACV, the design is to be such that
no secondary damage is to be caused and the control of the ACV is
to be maintained in the event of loss of the actuating system, or
mechanical failure of the linkages.