DH Deciphers | From wreckage to report: How experts investigate air accidents

The Dreamliner 787 crash in Ahmedabad that killed all but one passenger on board is one of the biggest air disasters in aviation history. Sumit Pande explains how civil aviation accidents are investigated.

Who conducts civil aviation incidents in India?

If an air incident is classified as an accident, the Aircraft Accident Investigation Bureau (AAIB), which operates under the Civil Aviation Ministry, appoints investigators. The Investigator-in-Charge is mandated to conduct investigations into the circumstances of the accident.

Who is involved in the investigation?

A notification is sent by the investigators to the countries where the aircraft was registered, manufactured, operated or designed as per the Aircraft (Investigation of Accidents and Incidents) Rules, 2017. Accredited representatives from the countries concerned then participate in the probe.

Since Dreamliners were manufactured in the US, a team from the National Transportation Safety Board (NTSB), a US probe agency, will assist the AAIB with its investigation. NTSB is the official US representative in the probe, while and Federal Aviation Administration — the US agency that regulates civil aviation in the country — will provide technical support. 

Is any UN agency involved in the investigations?

Since aircraft manufacturing involves multiple agencies spread across the globe, the International Civil Aviation Organisation (ICAO) — a United Nations agency — is also involved in the process. A total of 193 countries are members of ICAO, and the organisation facilitates cooperation on issues related to civil aviation.

How is evidence collected?

The first task before the investigators on reaching the site is to gather and preserve initial evidence that could be lost over time. This may include recording signs of impact, wreckage distribution, witness statements and retrieval of Flight Recorders or any component perceived to be of value to the investigators. They also gather recordings and data from the Air Traffic Controller, radar stations and CCTV footage.

How is the assessment of material evidence done?

The investigation team reviews all evidence to assess the need for a detailed examination of any specific components or equipment. Depending on the requirements, specialists from the industry and the aviation sector are requisitioned. The evidence and data thus collected are used to understand the circumstances that led to the accident.

How is the report finalised?

Upon examination and analysis of all available evidence, the investigation team prepares a report that includes “factual information, analysis, conclusions and safety recommendations". The report has to follow a format prescribed by the ICAO. The draft report is then shared with various agencies involved in the investigations, whose comments are sought to make “required amendments". The draft report is then submitted to the Director General (DG) of AAIB.

When is the final report approved?

After further process of consultation and review, the final report of the investigations conducted by AAIB is accepted by DG, AAIB. The report is made public “as deemed fit by DG, AAIB” and published. It is shared with the DGCA and other regulatory authorities in India. It is also sent to countries that have rendered assistance in the probe for necessary action.