The FMS calculates and displays recommended VSPEEDS based on gross weight, runway condition, derates, altitude, temperature, and other performance factors. REF is displayed in the header line for each speed when the value displayed is not pilot-entered or prompt-selected, as shown in Figure 4-38. VSPEEDS are displayed in small font until pilot-entered or prompt-selected.
FMS-recommended VSPEED computations are inhibited from display when the Takeoff Speed Inhibit OPC option is enabled. V1 computations are inhibited from display when the V1 Inhibit OPC option is enabled. Manual VSPEED entries are still permitted with either OPC option enabled. Valid entry range is between 80 and 300 inclusive.
Pilot-entered or uplinked takeoff speeds are limited to no less than the FMS-computed minimum V1, VR, and V2 speeds. When a pilot-entered or uplinked takeoff speed is less than the corresponding minimum value, the respective MIN V1, MIN VR, or MIN V2 header is displayed along with the associated minimum value.
