Fire and overheat indication systems include which indicators?

• A. Lights
• B. Horns
• C. Bells
• D. Lights, horns, bells, or a combination of the three

Answer: (D)

Fire and overheat indication systems rely on multiple ways to grab the crew’s attention so a warning is noticed quickly. Visual cues are provided by lights on the annunciator panel or cockpit indicators, while audible cues come from alarms such as horns or bells. Some installations use just lights, some use a horn, some use a bell, and many use a combination of these indicators. This redundancy and multimodal alerting help ensure the warning is perceived even if visibility or hearing is temporarily compromised. That’s why the best answer includes lights, horns, bells, or any combination of the three.