At what DME should you contact departure control after takeoff?

Contacting departure control after takeoff typically occurs at a standard distance from the runway, which allows the aircraft to establish a safe climb while providing the controller with necessary data about the aircraft's position. In this context, the appropriate distance to make that contact is generally considered to be 3 DME. This distance enables the aircraft to be well airborne and allows sufficient separation from the airfield environment. Additionally, contacting departure control at this point helps ensure that the transition to enroute phase and further instructions can be managed effectively.

Other distances, like 1, 2, or 4 DME, may not provide the required altitude or separation needed for efficient communication and traffic management, thereby making 3 DME the preferred choice.