When do the landing gear indications disappear from the PDU?

The landing gear indications on the Primary Display Unit (PDU) of the Dassault Falcon 7X disappear when the aircraft is above a specific altitude, particularly 18,500 feet, and the gear is indicated as up for a duration of over 10 seconds. This design feature helps to declutter the cockpit display for the pilots when the landing gear is confirmed to be up and out of the way, especially during cruise flight at high altitudes. This behavior reflects the aircraft's operational standards, where the landing gear status is less critical to monitor once the aircraft is at cruising altitude and the gear position is set accordingly.

In contrast, the other options do not accurately describe the conditions under which the landing gear indications would disappear. For instance, the indications will not disappear simply because the aircraft descends below 10,000 feet or immediately upon landing, as the status of the landing gear remains relevant to pilots during these phases. Similarly, during gear extension, it would not be appropriate for the indications to vanish since this phase of operation is crucial for confirming that the gear is deployed correctly.