Weather Radar & PWS System
NOTE
This is a stub page. Full system description pending ingest of FCOM Chapter 15.
Overview
The B777 Weather Radar provides weather detection and Predictive Windshear (PWS) alerting. PWS uses radar returns to detect windshear-producing microbursts ahead of the aircraft.
Key Facts
- PWS operates automatically when WXR is selected or during takeoff thrust
- Alerts provided at or below RA 1,200 ft
- Scanning active at or below RA 2,300 ft
- Detects moisture-laden microbursts only — dry microbursts not detectable
PWS Alert Types
| Alert | Trigger | Aural |
|---|---|---|
| Warning (T/O) | Windshear ahead during takeoff | ”WINDSHEAR AHEAD” |
| Warning (APP) | Windshear within 1.5 NM on approach | ”GO AROUND, WINDSHEAR AHEAD” |
| Caution | Windshear within 3 NM, RA ≤ 1,200 ft | ”MONITOR RADAR DISPLAY” |