When will number 2 rejoin on an instrument trail departure?

The scenario describes the protocol for number 2 to rejoin the formation during an instrument trail departure. For rejoining safely and effectively, the second aircraft must have visual contact with the lead aircraft (number 1) and receive permission to rejoin. This ensures both safety and coordination within the formation, as the pilots must be aware of each other's positions to maintain proper spacing and adherence to established procedures.

Visual confirmation is crucial because, under instrument flight rules, the lead aircraft may execute maneuvers that require the trailing aircraft to maintain a safe distance. By waiting for visual contact and permission, number 2 can ensure they are joining at the right moment, thus avoiding potential conflicts or loss of overall situational awareness.

In contrast, rejoining at night may add complications regarding visibility and situational awareness, making it less ideal as a blanket statement. Climbing or completing checklists also do not address the critical need for visual assessment and coordination between the two aircraft before rejoining.