[1] A missed approach may be either initiated by the pilot or instructed by air traffic control (ATC).
Such a request may include heading and altitude instructions to avoid in-flight delays (such as holds) and efficiently maneuver the aircraft into position for either its next approach or a diversion to an alternate airport.
It is also common for pilots to practice a missed approach as part of initial or recurrent instrument training.
The missed approach procedure normally includes an initial heading or track to follow, and altitude to climb to, typically followed by holding instructions at a nearby navigation fix.
The pilot is expected to inform ATC by radio of the initiation of the missed approach as soon as possible.