If you lose your DME at KDAB, how would you decide when to go missed?

The correct choice in this scenario is to use time (DIYAK to MAP) when deciding to go missed. This approach is based on a predetermined method established during your training or in the approach procedure that allows you to safely determine the appropriate moment to initiate a missed approach if the DME becomes unavailable.

When flying an instrument approach, particularly one that provides distance information from a specific point or waypoint, using timing can be crucial. If DME is lost, you can reference the time it usually takes to reach the missed approach point (MAP) from the last fix, in this case, DIYAK. By timing your descent based on how long it generally takes to travel from that point to the MAP, you can maintain situational awareness and ensure you are following a structured, predictable process if visual cues or distance measuring equipment fail.

The emphasis on time over other methods is that it provides a consistent and repeatable basis for decision-making in an instrument environment, where visual references may not be reliable due to weather or visibility conditions.