Precision approach is different from non-precision approach and belongs to instrument approach. Instrumental method and visual method are relative.

The difference between precision approach and instrument landing is very simple, that is, there is no glide slope indication. As long as the ground navigation platform provides a glide slope, it is a precision approach such as ILS or microwave landing; As long as the ground is not provided, if the pilot is required to master the instrument approach of gliding aircraft through flight time, DME distance, IRS system or GPS system, it is a non-tight approach.