Annunciator Panel: How to Read the Lights

Most people imagine cockpits are busy areas with a bevy of controls. From switches and knobs to dials, these controls run all the systems in an aircraft. An integral part of this system is the annunciator panel. It’s also known as the centralized warning panel, or CWP.

What is an annunciator panel?

This is a set or array of lights that indicates the condition of equipment or systems in an aircraft, building or industrial process. These panels are often designed with a main warning lamp, along with a series of panel indicator lights that catch the attention of the pilot in case something goes wrong or if an emergency situation springs up.

What do the colors mean?

The panel lights up with four colors. Each color corresponds to a different meaning. Take a look at what these colors mean:

  • Red. Flashing red signs mean bad news, says Gizmodo. That’s true for all aircrafts, not just for a modernized 737. It means a system or device needs immediate attention such as a broken hydraulic pump or sudden engine fire. If left unattended, that could result in a serious emergency situation.
  • Amber or yellow. Panel indicator lights in yellow don’t denote an emergency but rather Caution. That means it isn’t a piece of good news either since it indicates that a problem has come up, one that requires attention like a fuel imbalance. You’ll need to see to the problem before it gets worse, though.
  • Green. This is a sign that says all systems all. It basically tells pilots that a system is ready for use or that a system is in use.
  • White or blue. This means a system is on, which is the kind of light that goes on when the seatbelt signs are lit.

These are just a few essential things to know about annunciators and how to read panel indicator lights. If you ever find yourself in a cockpit someday and behind the controls, these will definitely come in handy.