Official UPSC Format

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 :

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.

⚡ Quick Recall Snippet

Modern aviation 'Black Boxes' consist of the Cockpit Voice Recorder (CVR) and Flight Data Recorder (FDR). To survive catastrophic crashes, their memory units are armored in stainless steel or titanium. When submerged, they emit acoustic pulses for sonar detection, rather than light pulses.

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Detailed Solution & Authority Citations

Correct Answer is Option B
According to the International Civil Aviation Organization (ICAO) specifications for flight recorders:
  • Statement 1 is Incorrect: When an aircraft crashes into water, the attached Underwater Locator Beacon (ULB) activates. Because light cannot penetrate the deep ocean, the ULB emits an acoustic (ultrasonic) pulse (usually at 37.5 kHz) that can be detected by sonar. It does not emit red light pulses.

  • Statement 2 is Correct: The term "black box" is colloquial; it actually refers to two bright-orange devices: the Cockpit Voice Recorder (CVR) (capturing crew conversations and engine acoustics) and the Flight Data Recorder (FDR) (logging hundreds of technical parameters like altitude and speed).

  • Statement 3 is Correct: The critical data is housed in the Crash-Survivable Memory Unit (CSMU). To withstand massive impact forces, crushing deep-sea pressure, and post-crash fires up to 1,100°C, the CSMU is armored with heavy-duty titanium or stainless steel and packed with high-temperature insulation.
    • Conclusion: Statements 2 and 3 reflect accurate aviation engineering.

    🚨 The Examiner's Trap

    The examiner uses a visually intuitive but scientifically false concept ('red light pulses') in Statement 1. Because people associate emergencies with flashing lights, candidates without a grasp of oceanic physics might incorrectly assume a light beacon is used underwater.

    Active Recall Flashcard

    Tap to Flip

    What type of signal does a Black Box's Underwater Locator Beacon (ULB) emit to guide search teams?

    An acoustic (ultrasonic) pulse, not a light pulse.

    Concept Flow Mapping

    Black Box
    Contains
    Cockpit Voice Recorder (CVR)
    Black Box Memory Unit
    Made Of
    Titanium or Stainless Steel
    Underwater Locator Beacon
    Emits
    Acoustic Pulses

    Logic Quest

    "Why use acoustic pulses instead of light for underwater beacons?"

    Not analyzing core concepts like Aviation Safety Engineering and Forensics through the lens of Previous Year Questions is a serious miss-out. This PYQ engine is specifically designed to help you decode the examiner's mindset and master highly probable Science & Technology questions for your upcoming Prelims.