Figure 1

Numerical simulation of the consequences of the time-dynamics of the affordance of deck-landing-ability on (A) the future velocity at touchdown (\({V}_{td}\)) depending on the applied lift (where \({Lift}_{min}\) is the minimum lift a helicopter can reach and \({Lift}_{max}\) is the maximum lift pulling the helicopter upward), and on (B) the helicopter’s trajectory relative to the ship’s deck. (A) The applied lift can belong to three areas in the figure. When located in the white area, it rules out landing on the ship (i.e., no deck-landing should be attempted) and it is recommended to abort the deck-landing maneuver. When the lift corresponds to the colored areas, it corresponds to ideal lift values compatible with landing with \({V}_{td}\) <\({V}_{crt}\) (i.e., with safe deck-landing). Green to red colors encode the distance from \({V}_{td}\) to \({V}_{crt}\). Several colored areas are presented here over time, as successive ship’s heave movements may give other possibilities for landing with \({V}_{td}\)< \({V}_{crt}\). When the lift is located in gray areas, it leads to land with \({V}_{td}\) > \({V}_{crt}\) (i.e., unsafe deck-landing). White areas show lift which lead to avoid any contact with the deck. The bottom panel shows the corresponding helicopter trajectories relative to the ship deck’s vertical heave in the case of the three scenarios.