What conditions must be met to be number one for departure in the landing pattern?

To be number one for departure in the landing pattern, it is essential that the flaps are up and that the aircraft in the upwind position has initiated the crosswind turn. This indicates that the aircraft has completed its take-off phase and is ready to efficiently transition into the departure phase.

Having the flaps up signifies that the aircraft is configured for climbing rather than descending, which is crucial for maintaining optimal performance and ensuring a safe ascent. The initiation of the crosswind turn by the upwind aircraft demonstrates that it is safely moving away from the runway and giving space for the next aircraft to follow in the pattern. Together, these conditions ensure a smooth and safe flow of operations, as the aircraft in the landing pattern can cleanly separate from those taking off.

In contrast, the other options present scenarios that do not satisfy the necessary conditions for departing. For instance, if the flaps are down or if the aircraft on downwind has lowered flaps, those conditions imply a configuration more suited for landing rather than departure. Each of these aspects highlights the critical safety protocols in maintaining an efficient flying operation within the controlled landing pattern.