At what pressure altitude does the CKPT ALT annunciator light turn on?

The CKPT ALT annunciator light activates at a pressure altitude of 19,000 feet. This system is designed to alert the crew when the cockpit altitude exceeds this specified threshold, indicating a potential cabin pressure loss or related issue. At this altitude, maintaining proper cabin pressure becomes critical for the safety and comfort of the crew and passengers, as the risk of hypoxia increases due to reduced atmospheric pressure. Operating aircraft systems effectively requires an understanding of pressure altitude thresholds, and the illumination of the CKPT ALT light serves as an essential warning to prompt the crew to take appropriate action to ensure safety and operational integrity.