This is a Significant Technology milestone.
'Direct Control' is the manual tilting of the rotor head by the pilot (via a control stick) to achieve pitch and roll control. This was the first method implemented to improve low speed control in autogyros, which led to the removal of fixed wing type controls (see the milestone for the Cierva C.30 for details of the system).
Source: AHS 2018 VTOL History Calendar