Plain English Meaning

Extra numbers printed on an approach chart that help the pilot plan a steady descent to the runway instead of dropping down in steps. They show the descent angle, where the descent should begin, and how fast to come down at different speeds.

Full Definition

Vertical navigation data shown on an instrument approach chart that supports a stabilized, constant-rate descent from an initial fix down to the runway. It typically includes a recommended descent angle, a visual descent point, and a table of descent rates needed to maintain that angle at various groundspeeds. On non-precision approaches, this information is advisory — it helps the pilot fly a smooth descent profile rather than a series of -downs, but it does not replace the published .