Which two devices are designed to automatically record flight information for investigation purposes?

The Cockpit Voice Recorder (CVR) and Flight Data Recorder (FDR) are specifically designed to record crucial flight information that can be used in the investigation of aviation incidents and accidents.

The Cockpit Voice Recorder captures all audio communications in the cockpit, including conversations between the flight crew, and sounds such as alarms or even aircraft noises, providing investigators with context regarding the crew's actions and decisions. Meanwhile, the Flight Data Recorder tracks and collects a vast array of flight parameters, such as altitude, speed, heading, and control inputs, over the course of a flight. This data is critical for understanding the performance of the aircraft during the incident and determining the sequence of events leading up to it.

Together, these devices serve as essential tools for safety investigations, enabling experts to analyze flight events comprehensively and improve aviation safety protocols. The other options mention devices that do not fulfill the specific role of recording detailed operational information for investigative purposes. For example, while an autopilot assists in controlling the aircraft, it does not record data, and navigation systems typically provide guidance rather than record data.