Second Black Box Recovered from Air India Crash Site

The officials have recovered the second black box, Cockpit Voice Recorder (CVR) from Air India plane crash site, said PK Mishra, Principal Secretary to Prime Minister Narendra Modi, in an official statement. The first black bax was discovered on Friday from the rooftop of a building at the site of Air India Flight AI-171 crash in Ahmedabad.

Black box are two flight recorders essential for post crash investigations:

1. Flight Data Recorder (FDR)

It Captures airspeed, altitude, heading, engine performance, flap settings etc. It helps in reconstructing the aircraft's flight path and system operation.

2. Cockpit Voice Recorder (CVR)

It Captures last 2 hours of cockpit conversations, pilot communications with ATC, ambient cockpit noise and warning sounds. It also helps understand human factors crew decision-making, stress levels and any last minute alarms.

Investigators recovered the Flight Data Recorder from the section of the wreckage. The FDR was intact and is being analyzed in Delhi by the Aircraft Accident Investigation Bureau (AAIB-India), with help from US NTSB and Boeing experts.

After intensive ground excavation and drone-assisted thermal imaging, the Cockpit Voice Recorder (CVR) was recovered from under debris in the forward fuselage. It was partially charred but structurally intact, meaning the memory may be salvageable.

Purpose

Recording Conversations: CVRs capture conversations between the flight crew, as well as any ambient sounds, such as alarms and engine noises.

Accident Investigation: The primary purpose of a CVR is to aid in the investigation of aviation accidents and incidents by providing insights into the crew's actions and decisions leading up to an event.

Features

Duration: Most modern CVRs can record audio for a minimum of 2 hours, with some capable of recording for longer periods.

Data Protection: CVRs are designed to withstand extreme conditions, including high temperatures, pressure, and impact forces, to ensure the data is preserved even after an accident.

Automatic Activation: The recorder is automatically activated when the aircraft's engines are running.

Data Retrieval

Post-Accident Analysis: In the event of an accident, investigators retrieve the CVR to analyze the recorded data, which can provide critical information about the flight crew's actions and the aircraft's operational status.

Design & Construction

The design and construction of a black box, which encompasses both the Cockpit Voice Recorder (CVR) and the Flight Data Recorder (FDR), prioritize durability, reliability, and data integrity in the challenging environment of aviation. Constructed from robust materials like titanium or aluminum, black boxes are engineered to withstand extreme conditions, including high-impact forces and intense heat, ensuring they remain intact during accidents.

The recorders utilize solid-state memory technology for reliable data storage, allowing for extended recording durations and quick retrieval. Additionally, they are sealed to prevent water ingress, making them waterproof and capable of functioning even if submerged.

Typically installed in the tail section of an aircraft for maximum protection, black boxes are equipped with an Underwater Locator Beacon (ULB) that activates upon immersion, aiding in recovery efforts. Compliance with international aviation regulations ensures that these devices meet stringent safety and performance standards, making them essential tools for enhancing aviation safety and facilitating thorough accident investigations.

Initial Hypotheses Being Explored

1. Engine failure or thrust asymmetry

2. Autopilot or flight computer malfunction

3. Improper flap deployment or retraction

4. Crew disorientation or failure to respond to warnings

5. Contamination in fuel or hydraulic fluid

Who is Involved in the Investigation?

AAIB- Lead investigator under DGCA mandate.

DGCA- Regulatory oversight has grounded similar aircraft for checks.

Boeing- Providing aircraft data, maintenance records and technical input.

NTSB (USA)- Technical advisory role, given Boeing is a US company.

Local Police and Forensics Teams- Site security, DNA indentification of victims.