Missed Approach

When, for any reason, it is judged that an approach cannot be continued to a successful landing, a missed approach or go-around is flown. 
Reasons for discontinuing an approach include the following: 

 -The required visual references have not been established or is acquired but is subsequently lost.

- The aircraft is not positioned so as to allow a controlled touch down within the designated runway touchdown zone with a consequent risk of aircraft damage with or without a Runway Excursion if the attempt is continued.

- The runway is obstructed; Landing clearance has not been received or is issued and later cancelled. 

- A go-around is being flown for training purposes with ATC approval.