“Most plane crashes are due to human error”

• On Saturday, five people were killed in a plane crash in Isère.

  The research section of the air transport gendarmerie was responsible for directing the investigations.

• Every year, this specialized unit of the gendarmerie, created in 2004, investigates about twenty plane accidents.

• Its commander, Colonel Laurent Chartier, explains to us the progress of the investigations.

The crash killed five people, including two children aged 11 and 14.

On Saturday, a passenger plane crashed in the Belledonne massif, in Isère, shortly after takeoff.

The aircraft was found completely charred.

To determine the causes of the accident, the Grenoble public prosecutor's office opened an investigation entrusted to the Isère gendarmerie group and the research section of the air transport gendarmerie.

Each year, this specialized unit, created in 2004 after the Concorde crash, investigates about twenty serious plane accidents, both in France and abroad.

At the head of the 45 investigators who compose it, Colonel Laurent Chartier, details at

the progress of the investigations.

How does the work of the research section of the GTA relate to that of the BEA, the accident investigation office?

When a plane crashes, two investigations are opened in parallel: an administrative investigation, conducted by the BEA, and a judicial investigation that we conduct under the authority of a public prosecutor's office.

The purpose of the administrative investigation is to find the causes of the accident in order to communicate them to the aeronautical community.

The goal is to prevent it from happening again.

All BEA reports are therefore public and published on their website.

On our side, we are also trying to understand the causes of the accident but to determine responsibilities.

During the first two phases of these two investigations – the preliminary observation phase and the first collection of information – we work together with the BEA.

This involves the seizure of elements on the scene, such as parts of the aircraft, electronic devices found with the victims, telephones, tablets which were used for shooting or preparing the flight plan … These elements are then placed under judicial seal.

The data collected is kept by the BEA for its own analysis.

They will also be used by investigators from our units.

For some more technical data, we will request an expert from the courts so that he can analyze or interpret this data with us.

Concretely, how does an intervention on a crash take place?

The investigation is often entrusted to a local unit and to the GTA which leads the investigations.

Once the crash is known and the aircraft located, the first responders – from the nearest police or gendarmerie units – will identify the first witnesses and protect the premises.

They are the ones who will manage the examination and the recovery of the bodies.

Indeed, they have crime scene technicians capable of managing this part and they know the nearest forensic institute with which they regularly work.

Most of the time, a medical examiner goes on site to make the first findings on the bodies.

The findings on the wreckage and analysis of the accident and the aircraft are entrusted to a unit of the GTA.

We focus on the scene of the accident by noting the engine components that we will be able to find, the fuel samples that we will be able to take.

Then there will be witness hearings, the identification of the aircraft maintenance workshop.

We get the last acts of maintenance of the device, we interrogate the surrounding control towers to find out if there have been recorded radio contacts, the national air operations center in Lyon which could have a radar trace of the trajectory of the aircraft before the accident.

We are making requisitions with Météo-France to find out the precise weather conditions at the scene at the time of the crash.

We even ask the French aerospace agencies to find out if there were meteor showers that could have struck the aircraft.

This has never happened in France but we do not rule out any French hypothesis.

On the other hand, it happens that an aircraft strikes a bird.

How do you then determine the causes of the accident from these elements of the investigation?

In recreational civil aviation, most accidents are due to human error.

The material is rarely blamed.

In France, there is serious maintenance and monitoring of devices, even if they seem old.

Even qualified pilots can, on a given day, have a bad appreciation of the power of their aircraft.

In question, an overload of the device, a bad distribution of the loads, a bad management of the fuel in the device... The accident can also be caused by problems related to the weather, in particular what is called the " carb icing”: the air sucked in is cold and can icing the carburettor if there is a lot of humidity in the air.

There have also been accidents in the mountains where people have been trapped by the weather or have been too optimistic about the capabilities of their machine.

They find themselves in aerial corridors above mountain ranges and the power of their machine is not enough to pass over a pass.

Crash in Isère: three members of a family among the victims

Five dead in the accident of a tourist plane in Isère

• Crash

• Isere

• Airplane

• Plane crash

• Gendarmerie

• Investigation

• Interview

• Miscellaneous facts

• Auvergne-Rhône-Alpes