Hallo Olli,
hab mal für dich ins Manual der DF737 geschaut:
Right 1 - VREF LINE - Flaps 15
-Displays the landing Vref for flap 15 setting, as calculated by the FMC. Speeds are based on the displayed GROSS WT.
-Vref will be displayed on the EADI speed tapes when there is a manual entry or a double line selection.
Also besser nicht unter den Wert gehen
Gruß Heinz