Aircraft Accident Investigation Bureau (AAIB)

A plane comes down, or nearly does. Passengers want to know why. So does the airline, the maker and the regulator. But there is a problem. If the regulator itself leads the inquiry, it may be judging its own work. India solved this by creating a separate body just to find the truth. What does the Aircraft Accident Investigation Bureau do, and why is it kept apart from the DGCA?

1What Is the AAIB?

• The full form is the Aircraft Accident Investigation Bureau. It is India’s independent authority for investigating air accidents.
• It is an attached office of the Ministry of Civil Aviation. Its headquarters is at Udaan Bhawan, Safdarjung Airport, New Delhi.
• It was set up on 30 July 2012. Before that date, the job sat inside the DGCA, the Directorate General of Civil Aviation.
• Its work is simple to say and hard to do. It finds out why an aircraft came down, or nearly did, and writes a report so that it does not happen again.
• To do this, it can get at the evidence without asking anyone’s permission first. That includes wreckage, records and flight recorders.

2Why Must the Investigator Be Separate from the Regulator?

• Think of a school where the principal also marks the principal’s own report card. The marks would not inspire trust. Aviation faced the same problem.
• Before 2012, accident inquiries were handled by the Air Safety Directorate of the DGCA. But the DGCA is also the regulator. It licenses pilots, certifies aircraft and checks airlines.
• So an accident caused partly by a regulatory lapse would be probed by the same office that made the lapse. That is a clear conflict of interest.
• The fix was to split the two jobs. The DGCA keeps regulating. The AAIB investigates. Each does one thing.
• An independent body can then say what went wrong without having to protect anyone. That is why a clean split matters more than any single report.
• The AAIB works under the Aircraft (Investigation of Accidents and Incidents) Rules, 2017. These follow international rules, which we will meet shortly.

3How Does the AAIB Sort What Happened?

• Not every bad moment in the air is a crash. So the AAIB sorts events into three tiers and decides how deeply to investigate each one.
• Accident: the most serious tier. It involves deaths, serious injuries or major damage to the aircraft.
• Serious incident: an event where an accident almost happened. Nobody may be hurt, but the danger was real. A near-collision is a good example.
• Incident: the mildest tier. It is still worth recording, because small events often warn of bigger ones.
• Who decides which tier an event belongs to? The AAIB does. Its classification is final and binding.
• Why track near-misses at all? Because the cheapest lesson is the one learned before anyone is hurt.

4What Do Rules 3 and 11 Say?

• Rule 3 is the heart of the system. The sole objective of an investigation is the prevention of accidents and incidents. It is not to apportion blame or liability.
• The same rule keeps the investigation separate from any court or administrative case that fixes blame. The two run on different tracks.
• Why design it this way? If pilots and engineers fear punishment, they may stay silent. If they know the aim is safety, they speak openly.
• Rule 11 says when the AAIB must act. It must investigate every accident, and serious incidents involving aircraft of more than 2,250 kg or any turbojet.
• For lighter aircraft, the AAIB may choose to investigate a serious incident, but it is not forced to.

5What Is the Global Model?

• India did not invent this split. It follows ICAO Annex 13, the international standard on aircraft accident investigation. ICAO is the International Civil Aviation Organization.
• The United States has the same design. The NTSB, the National Transportation Safety Board, investigates. The FAA, the Federal Aviation Administration, regulates.
• India mirrors this. The AAIB is the investigator. The DGCA is the regulator.
• Findings do not stop in a file. Recommendations go to the regulator, airlines and makers, and can change training, procedures or rules.
• That feeds into India’s State Safety Programme, the national framework that links data, oversight and investigation.

6What Has the AAIB Looked At Recently?

• On 7 August 2020, an Air India Express Boeing 737-800 crashed while landing at Kozhikode in heavy rain. Twenty-one people died, including both pilots.
• The AAIB’s final report named the pilot’s non-adherence to standard procedure as the probable cause. It also said systemic factors played a role, and it made safety recommendations.
• On 12 June 2025, Air India flight AI171 crashed after take-off from Ahmedabad. The AAIB led that probe and released a preliminary report on 12 July 2025.
• Now the newest story. On 4 August 2026, Air India flight AI2379 was flying from Phuket to Delhi when the aircraft suddenly lost about 300 feet in cruise.
• Reports say there was a temporary loss of hydraulic pressure. The flight carried 137 passengers and 8 crew, and it landed safely in Delhi.
• The event was classified as a serious incident and given to the AAIB. The probe was still going on at the time of writing, so no cause has been announced.
• This is the system at work. Nobody was killed, yet the event is still investigated, because it was a near-miss.

7What Should You Remember for Exams?

Must Know

• The AAIB was set up on 30 July 2012.
• It investigates air accidents and serious incidents.
• It is separate from the DGCA.

Good to Know

• Occurrences are Accident, Serious Incident and Incident.
• Rule 3 says the aim is prevention, not blame.
• Rule 11 covers serious incidents on aircraft above 2,250 kg or any turbojet.

Great to Know

• The AAIB is not a part of the DGCA (Trap).
• Its work follows ICAO Annex 13, like the NTSB and FAA split in the United States (Trap).
• Its classification of an occurrence is final and binding (Trap).