A system for enabling successful use of HID lamps in aircraft, including in particular high power lamps for use as landing lights and taxi lights, utilizes a sealed beam HID lamp which during normal operation has an external temperature considerably lower than the external temperature of a quartz halogen or incandescent sealed beam lamp of equivalent light output. The lower external temperature arises in part from the use of a gas fill in the sealed beam. A detector is provided to monitor the seal integrity of the sealed beam HID lamp and further to provide a response to seal failure resulting in disablement of the lamp. Exemplary means for accomplishing seal failure detection include radioactive detection, pressure monitoring, and chemical sensing, or other means wherein detection of a failed seal is followed by an electrical output used to terminate or preclude lamp operation.