What is a Black Box?

What is a Black Box?

Why in News?

Recently, after the Air India flight AI171 crash in Ahmedabad, its black box was recovered. The analysis of this device is expected to provide critical clues to the investigating agencies in identifying the actual causes of the accident.

What is a Black Box?

• A Black Box is a specialized device that records all critical information related to the operation of an aircraft.
• The core purpose of this device is to assist investigators by offering reliable data after an aircraft mishap.
• In reality, it is painted in orange or yellow color to make it easier to locate at a crash site.
• The concept of the Black Box emerged in the 1950s, when the reasons behind air crashes remained unknown.
  • Australian scientist David Warren is credited with its invention.
• Earlier models recorded limited data on wire or tape, but modern Black Boxes use solid-state memory chips that store a larger volume of data and are more secure.
• Modern black boxes consist of two vital units — the Flight Data Recorder (FDR) and Cockpit Voice Recorder (CVR).
• Black Boxes are designed to withstand severe accidents, explosions, extreme heat, and deep-sea pressure.
• The Crash Survivable Memory Unit (CSMU) inside is built from strong metals like steel or titanium.
• It can withstand shocks up to 3400 G, temperatures above 1000 degrees Celsius, and deep-sea pressure.
• Its structure made of titanium or steel gives it the strength of granite.
• To improve survival chances during crashes, black boxes are installed near the aircraft’s tail section.
• In case of a sea crash, an Underwater Locator Beacon (ULB) or “pinger” is attached, which emits signals for at least 30 days.
• Extracting data from a Black Box is not easy; it usually takes 10 to 15 days.
• Experts analyze the flight details, cockpit audio, engine condition, and pilot activities retrieved from the Black Box.
• All commercial airlines are now required to equip their aircraft with black boxes as per aviation safety norms.

Main Components of the Black Box

The Black Box consists of two main parts: the Flight Data Recorder (FDR) and the Cockpit Voice Recorder (CVR). These two components together store every essential piece of information related to the flight, helping to understand the cause of an accident.

• Flight Data Recorder (FDR):
  • The FDR logs numerous flight parameters like speed, altitude, and engine behavior throughout the journey.
  • Its purpose is to determine how the aircraft was functioning at the time of the accident.
  • This device stores technical information like airspeed, altitude, pitch, heading, and engine performance.
  • Modern FDRs can record thousands of parameters, including the position of flaps, fuel flow, rudder control, and autopilot status.
  • During an accident, the analysis of this data helps determine whether it was caused by technical failure, human error, or external factors.
• Cockpit Voice Recorder (CVR):
  • The Cockpit Voice Recorder, or CVR, captures the audio environment inside the cockpit, including pilot conversations. 
  • It serves as crucial evidence in investigations.
  • The CVR records pilot discussions, radio communications, warning signals, and even engine sounds.
  • The CVR retains cockpit audio for the last two hours, regularly updating and overwriting previous recordings.
  • In the event of a crash, the CVR helps determine what kind of discussions, decisions, and reactions the pilots had.
  • It can reveal whether a technical issue arose in the final moments of flight.

How Does a Black Box Work?

• The primary role of the Black Box is to store technical data and cockpit audio related to the aircraft.
• Once the aircraft takes off, the black box begins recording flight data and cockpit sound without manual input.
• It stores every second’s worth of data and audio during the flight.
• The recording continues until the aircraft comes to a complete stop or an unusual event occurs.
• The FDR logs data such as speed, altitude, direction, and engine performance.
• The CVR records vital cockpit interactions, including pilot conversations, alerts, and ambient cockpit sounds.
• Together, both recorders provide a complete picture of the aircraft’s behavior and events.
• After an accident, the data retrieved from the Black Box is analyzed in-depth by a team of experts.
• This investigation process may take a few days.
• Based on the extracted data, the actual cause of the crash is determined.
• It enables airlines and regulatory agencies to take corrective actions.

Responsible Organization for Aircraft Accident Investigation in India

• In India, when an aircraft accident occurs, a specialized organization is responsible for conducting a fair, independent, and expert investigation. This organization is the Aircraft Accident Investigation Bureau (AAIB).
• The Aircraft (Investigation of Accidents and Incidents) Rules, 2012 were officially notified via a government gazette.
  • To ensure unbiased aircraft crash investigations, the Indian government set up AAIB on 30 July 2012.
• In 2017, AAIB’s role was strengthened by declaring it an “Attached Office” within the Civil Aviation Ministry.
  • This change was made in accordance with ICAO Annex 13 and the Indian aviation context.
• Currently, investigations are conducted under the Aircraft (Investigation of Accidents and Incidents) Rules 2017 and the 2021 Amendment.
• AAIB has the legal authority to access crash-related evidence instantly and without any prior approvals.
• It does not need prior permission from the courts or other government agencies.
  • Earlier, this responsibility was handled by the Air Safety Directorate of the DGCA.

As per international standards, following the recommendations of the International Civil Aviation Organization (ICAO), it was deemed necessary to separate the investigation function from the regulatory body.