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 :

Option (B) — 2 and 3 only

• Black boxes in aircraft consist of two units: the Flight Data Recorder (FDR) which records flight parameters, and the Cockpit Voice Recorder (CVR) which records audio from the cockpit. Together they record both voice and flight data.
• Black boxes carry an Underwater Locator Beacon (ULB) that emits ultrasonic pulses (at 37.5 kHz), not red light pulses. These acoustic pings can be detected underwater for up to 30 days or more to help locate submerged wreckage.
• The crash-survivable memory units of black boxes are encased in robust materials such as stainless steel or titanium to withstand extreme impact, fire, and deep-sea pressure.

• 1. They carry a beacon emitting red light pulses to facilitate underwater detection: Incorrect. Black boxes use Underwater Locator Beacons (ULBs) that emit ultrasonic acoustic pulses, not red light pulses. Light would be ineffective for underwater detection at depth.
• 2. They record both the cockpit voice and flight data: Correct. Modern aircraft carry both a Cockpit Voice Recorder (CVR) and a Flight Data Recorder (FDR), collectively known as black boxes, recording audio and hundreds of flight parameters.
• 3. Their memory units are made using either stainless steel or titanium: Correct. The memory units are housed in crash-survivable enclosures made of stainless steel or titanium to protect data from extreme conditions including high temperatures, pressure, and impact.