What are two types of smoke detectors used in aircraft?

The correct choice identifies two types of smoke detection systems commonly used in aircraft as photoelectric and thermal. Photoelectric smoke detectors utilize a light source and a sensor; they are designed to detect smoke particles by sensing changes in light patterns, making them effective for detecting smoldering fires. Thermal smoke detectors, on the other hand, respond to changes in temperature caused by smoke or fire, activating when a certain temperature threshold is exceeded. Both types are crucial for ensuring onboard safety, providing early warnings in the case of smoke detection.

The other options do not accurately reflect commonly used smoke detectors in aircraft. Ionization and thermal detectors are types recognized in some contexts, but they do not align as directly with the two main classifications often discussed in aviation safety. Radiation and chemical detectors are less commonly used in aircraft settings and are not typical in basic smoke detection applications. Anomalous and integrated does not correspond to recognized categories of smoke detection technology in aviation.