A "go-around" refers to a maneuver where an aircraft abandons its approach to a runway and initiates a climb away from the airport, usually due to safety concerns or unstable approach conditions.

A go-around is typically initiated when an aircraft is on final approach, but the pilot determines that it is not safe to land. This can be due to a variety of reasons, such as:

1. Unstable approach: The aircraft is not on a stable glide slope or is experiencing turbulence.
2. Air traffic control instructions: The pilot is instructed by air traffic control to go around due to traffic or other safety concerns.
3. Weather conditions: Poor visibility, wind shear, or other adverse weather conditions make it unsafe to land.
4. Aircraft performance: The aircraft is not performing as expected, or there is a system malfunction.
5. Obstacles on the runway: There are obstacles or other aircraft on the runway that prevent a safe landing.

When a go-around is initiated, the pilot will:

1. Advance the throttles to increase power
2. Retract the landing gear and flaps
3. Initiate a climb away from the airport
4. Follow established procedures for a go-around, which may include contacting air traffic control to advise them of the go-around and receive further instructions.

A go-around is a normal and safe procedure in aviation, and it is always better to err on the side of caution and initiate a go-around if there are any doubts about the safety of the approach or landing.