Classification
Precision approaches (ILS, GLS) provide lateral and vertical guidance to a decision altitude. Non-precision approaches (VOR, NDB, LOC) provide lateral only, with a minimum descent altitude. APV approaches such as LPV give vertical guidance from satellite augmentation.
Continuous descent final approach
Modern technique flies a constant-angle path even on non-precision approaches, using a derived vertical path instead of the old step-down profile. It reduces workload and controlled-flight-into-terrain risk.
The decision
At DA or MDA the required visual reference must be established or a go-around is mandatory. The decision is binary and pre-briefed; 'let's look a bit lower' is a documented accident cause.
Key points
- Precision = lateral + vertical guidance to a DA.
- LPV gives ILS-like minima using GNSS augmentation.
- No visual reference at minima means go around — no negotiation.
Knowledge check