Definition
A four-character alphanumeric code, beginning with the letter W, that uniquely designates a WAAS-based instrument approach procedure within the avionics database. The identifier links the loaded approach in the GPS/FMS to the published chart so the equipment can confirm it is flying the correct procedure.
Plain English
A short code starting with 'W' that the GPS uses to label and identify a specific WAAS approach, matching what is printed on the approach chart.
Context Anchor
Seen on instrument approach charts and in WAAS-capable GPS navigators when selecting or checking an RNAV (GPS) approach.
Derivation
WAAS stands for Wide Area Augmentation System, the FAA satellite-based system that improves GPS accuracy enough to support precision-like approaches. The leading 'W' in the identifier signals that the approach depends on WAAS.
Why Pilots Care
It confirms the approach supports lower decision altitudes and greater access to precision-like minima without ground-based equipment.
Grounding Statement
Before flying the approach, the pilot should be able to match the WAAS approach identifier in the navigator to the one printed on the chart.
Intuition Check
Do not treat the WAAS approach identifier as the approach title or as a measure of WAAS signal quality. It is a verification code for one specific WAAS approach procedure.
Example Sentence 1
Before starting the approach, the pilot cross-checked the WAAS approach identifier shown on the GPS against the one printed on the chart.
Example Sentence 2
Presence of the WAAS approach identifier allowed descent to the published LPV minima.