Piperboy
As I said above provided that the aproach is going well and we will not break the 500 ft rule the training will continue until a sucssesful landing is beyond doubt in the mind of the student.
This means that the student gets close enough to the field to know exactly what surface he/she has selected.
50 ft is the sort of height above the ground that you can expect a good aproach to be aborted.
Training that is not realistic is worthless.