Alerting Systems General Principles: Warning, Caution, and Advisory Logic

022-12-01Pablo Asensio Martínez2026-04-011 min

Overview

The Flight Warning System (FWS) ensures the flight crew is aware of abnormal aircraft conditions. Its primary functions are to:

  1. Draw attention to the condition (Aural/Visual).
  2. Identify the specific problem.
  3. Prioritize alerts based on urgency (Internal Logic).

Alert Categories (CS-25)

Alerts are categorized by the level of crew awareness and action required. The color coding is strictly regulated.

Category Color Definition Crew Action
Warning Red Emergency condition requiring immediate recognition and corrective action. Immediate
Caution Amber / Yellow Abnormal condition requiring immediate awareness and subsequent corrective action. Subsequent
Advisory Any (Prohibited: Red/Green) Condition requiring crew awareness. May be required

Safe Operation

  • Green is reserved for indicating safe, normal operation (e.g., Landing Gear Down & Locked). It is not used for alerts.

Location & Visibility

Master Warning and Master Caution lights must be installed in the pilot's direct line of vision (forward field of view) to ensure they are seen with minimum deviation from the normal flight path monitoring.