UPSC Prelims 2026 Question:

Which of the following statements with regard to Black Boxes used in modern aircrafts is/are correct?

1. They carry a beacon emitting red light pulses to facilitate underwater detection. 
2. They record both the cockpit voice and flight data. 
3. Their memory units are made using either stainless steel or titanium. 

Select the answer using the code given below: 

Answer: 2 

Explanation:  

Black boxes are crash-protected flight recorders used in aircraft accident investigation. Modern aircraft generally  carry two key recorders: the Cockpit Voice Recorder and the Flight Data Recorder. They are built to survive  severe impact, fire, pressure and underwater conditions so that investigators can reconstruct the final phases of a  flight. 

• Black boxes do not carry a beacon emitting red light pulses for underwater detection. They are fitted  with an Underwater Locator Beacon, which emits acoustic ultrasonic pulses, commonly called “pings”,  to help locate the recorder underwater. So, statement 1 is not correct. 
• Black boxes record both cockpit voice and flight data through two recorders: the Cockpit Voice  Recorder records sounds and communications in the cockpit, while the Flight Data Recorder records  aircraft parameters such as altitude, speed, heading and system performance. So, statement 2 is correct. 
• The crash-survivable memory unit of a flight recorder is protected by strong materials such as  stainless steel or titanium. These materials help the recorder withstand impact, high temperature and  deep-sea pressure. So, statement 3 is correct. 

Therefore, option (2) is the correct answer.