Air Crash Investigations: What Do They Entail?

In the aftermath of an aviation accident, a lot of work goes on behind the scenes. The purpose of this investigation is not to apportion blame for the crash, but rather to discover what went wrong so that it can be avoided in future. Here’s what happens during an air crash investigation.

air crash investigation
What happens during the investigation of a plane crash? Photo: Getty Images

Who investigates an air crash?

An air crash is a disaster on so many levels. Where lives have been lost, families are left grieving. Airlines’ reputations are tarnished, safety protocols of entire nations can be called into question, and even aircraft manufacturers can be implicated. While a very rare occurrence, every air crash must be thoroughly investigated to prevent a similar catastrophe from happening.

All air accident investigations follow the process that is laid out by the International Civil Aviation Organization (ICAO). Specifically, these processes are laid out in Annex 13 of the Convention on International Civil Aviation, also known as the Chicago Convention.

Involved in the investigation will be the government organization in the country where the accident happened. They have the option to call in help from other countries, too, if they feel they don’t have the right tools and knowledge to carry out the investigation.

As well as this, the country where the aircraft was manufactured as well as the country of the aircraft’s registration will be involved. This is why, in cases involving Boeing aircraft, for example, the Federal Aviation Administration (FAA) will be called in to help.

Canada was heavily involved in the crash investigation of a UIA aircraft. Photo: Getty Images

Other countries can elect to be involved in the investigation based on special interest. For example, in the case of Ukraine International Airlines flight PS752, the large number of Canadians onboard meant that Canada was heavily involved in the investigative process.

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What happens in the investigation?

As soon as the world discovers that an air crash has occurred, investigators will mobilize to begin their study of the incident. Initially, an investigator-in-charge will ensure it is safe for other investigators to visit the wreckage. This includes ensuring there is no hazardous cargo, toxic material, sharp objects or pressurized equipment on site.

Investigators will then visit the scene to take photographs and video assessments of the site. They will collect as much physical evidence as they can, as well as undertaking interviews with eyewitnesses. Using the wreckage as clues, they will chart the way the aircraft hit the ground, using the distribution of debris to indicate the angle of impact.

As much of the plane as possible will be salvaged and reassembled in somewhere like a hangar. This helps investigators to determine what happened, and to see which pieces are still missing.

air crash investigation
Planes will sometimes be reassembled in hangars. Photo: Getty Images

A key priority in these early stages is to retrieve the plane’s ‘black boxes.’ Two such devices are installed in all commercial aircraft – a cockpit voice recorder and a flight data recorder. The former, as you might expect, records conversations in the cockpit, including with air traffic controllers, while the latter stores information on the flight such as altitude, flight control inputs and instrument readings.

air crash investigation
Finding the two black boxes will be a priority. Photo: Getty Images

The technical investigation

While crash site investigators are busy collecting information, other groups are brought in to look at the technical aspects of the crash. These specialists may disassemble parts of the plane, such as engines or other components, and may use flight simulators to recreate the moments leading up to the crash.

They will also review the evidence surrounding the accident, such as crew experience and training, the aircraft maintenance records and external factors such as the weather. They will interview any survivors and individuals involved in the rescue operation. At the same time, forensic and medical experts will analyze the victim’s remains to test for drugs, alcohol and other influencing factors.

In some cases, where air crashes are particularly high profile, public hearings will take place to disseminate the findings of the investigation. This helps to ensure full transparency and the public’s understanding of what is taking place.

Dennis Muilenburg Boeing CEO
High profile crash investigations will include a public hearing. Photo: Getty Images

Drawing conclusions

Within 30 days of the crash, the investigating team must release their preliminary report. Sometimes the final report can take a year or more to produce, depending on how complex the issues surrounding the crash were.

This final report should identify what did and didn’t happen, how it contributed to the crash and what influencing factors are involved. In complex situations where the report takes more than a year to produce, investigators must release an update on the anniversary of the crash, detailing what progress has been made to date.

air crash investigation
Investigations are intended to improve future safety, not to apportion blame. Photo: Getty Images

Even before the final report is released, investigators can make recommendations for improvements to safety. For example, when Lion Air’s 737 MAX crashed, it was rapidly identified that a software fix was required. Boeing was working on this when the Ethiopian Airlines crash occurred.

The final outcome will inform the public of what happened, will outline all safety recommendations from the investigation and will mark the conclusion of the investigation. These reports are aimed at improving the safety of flying, rather than finding someone to blame.