If you’ve ever stepped into a cockpit, you may recall seeing a collection of small lights. Known as indicator lights, they provide pilots with real-time insight into various systems. Some indicator lights are mounted on annunciator panels, whereas others are integrated into displays or panels. For a better understanding of indicator lights and how they work, keep reading.
What Are Indicator Lights?
Indicator lights are small lights that provide information about various aircraft systems. They are found in cockpits. When an aircraft system changes state or needs attention, an indicator light may activate. Pilots will see the illuminated indicator light, at which point they can take the necessary action.
How Indicator Lights Work
Most indicator lights are powered by light-emitting diode (LED) technology. Like all LEDs, they work by passing an electrical current through a semiconducting material. This process releases energy in the form of photons, resulting in visible light.
Benefits of LED-based indicator lights include the following:
- Produces almost no heat
- Energy efficient (uses about 75% to 90% less energy than incandescent lights)
- Long-lasting
- Free of toxic chemicals like mercury
- Can reach full brightness almost instantly
- Safe and reliable
- Available in different colors
While indicator lights typically use LED technology, they are more than just basic LED lights. Rather, indicator lights relay information about aircraft systems. Some of them automatically activate when aircraft systems are turned on and running. Other indicator lights act as warning lights, illuminating in response to a problem with an aircraft system.
Indicator Light Colors
The color of an indicator light is important. Many airplanes use color-coded indicator lights. Blue or white indicator lights, for instance, provide general information about an aircraft system, whereas green indicator lights indicate an aircraft system is operating normally and as intended.
Amber indicator lights typically indicate caution. They activate when an aircraft system is out of range or otherwise not functioning normally. Finally, red indicator lights indicate a serious problem. If an aircraft system needs immediate attention, a red indicator light may activate to alert the pilots.
Placement of Indicator Lights
Most indicator lights are found on annunciator panels. They are typically grouped together by system. With this system-based grouping method, pilots can easily identify problems. If a red light activates in the landing gear grouping system of the annunciator panel, for instance, pilots will know that there’s a serious problem with the landing gear.
