The display unit (DU) shows radio altitude and radio minimums values. The flight crew uses this data during an approach and a landing.
Radio altitude shows in white for airplane altitude between -12 and 2500 feet. This is when the radio altitude values update:
· Two foot increments from -12 to 100 feet
· Ten foot increments from 100 to 500 feet
· Twenty foot increments from 500 to 2500 feet.
The radio altitude does not show above 2500 feet.
The radio altitude display shows a white highlight box around it for ten seconds when the radio altitude initially shows on the display unit.
The green radio minimums display shows below the ADI display. The radio minimums display does not show for these reasons:
· Baro minimums is selected on the EFIS control panel
· Radio minimums reset switch is pushed
· Radio minimums value is less than zero.