Plain English Meaning

Using an approved GPS instead of older radio-based equipment to fly a procedure that was originally designed around that older equipment.

Full Definition

The authorized use of a properly certified GPS receiver in place of a traditional ground-based navigation receiver (such as DME or ADF) to satisfy the equipment requirements of an instrument approach, departure, or en route procedure. The GPS unit must meet specific FAA approval standards, and the pilot must monitor the equivalent ground-based facility's status to ensure the procedure remains usable.