As investigators pore over the sequence of events that led to the worst air disaster of 2016, attention is focused on the captain of the plane, Miguel Quiroga, and the decisions he took on fuel provision and alerting air-traffic control.

Seventy-one people, including most of the players on a leading Brazilian football team, died when their chartered Avro RJ85 jet crashed on the approach to Medellín’s main airport. They had departed from Santa Cruz in Bolivia on the final leg of a journey to the Colombian city for the first leg of the Copa Sudamerica final.

The aircraft was chartered from LaMia, based in Santa Cruz. Bolivia’s aviation authority, the DGAC, has grounded the airline indefinitely.

The initial decision to deploy a commuter jet designed for short hops on a flight of 1,850 miles looks questionable. The journey is the same distance as Belfast to Istanbul – a route that would not be sanctioned as a regular scheduled route using such a plane.

The longest regular trip made by the aircraft type is believed to be 1,625 miles between Perth in Australia and Christmas Island, a journey of about four hours. The RJ85 had been flying for almost five hours when it crashed.

A flight plan leaked to the media shows the “estimated elapsed time” – ie the predicted length of the flight – as four hours, 22 minutes. The “endurance”, or maximum flying time, is shown as exactly the same.

Three hours into LaMia flight 2933, the aircraft passed over Leticia airport, in the Colombian Amazon. By this stage the pilots should have had a clear picture of the amount of fuel remaining in the tanks.

About four hours into the flight, the aircraft could have diverted to Bogota, the declared alternate airport.

At about that time, an AeroColombia flight took off from the Colombian capital, destined for the Caribbean island of San Andres. It then declared a diversion to Medellín because of a mechanical fault. The LaMia aircraft was ordered to fly a holding pattern while the AeroColombia flight was given priority to land. It is feared the manoeuvre exhausted the available fuel.

International aviation law requires the pilot-in-command to ensure that there is always enough fuel on board “to proceed to an aerodrome where a safe landing can be made with the planned final reserve fuel remaining upon landing.”

The absolute minimum “planned final reserve fuel” allows for the aircraft to fly for half an hour at holding speed at an altitude of 1,500 feet above the airport.

When the crew predict that landing at the nearest safe airport will result in having less than the planned final reserve, they are required to declare a fuel emergency by broadcasting “Mayday, Mayday, Mayday, Fuel”.

Air-traffic controllers are then obliged to prioritise the aircraft to enable it to land as soon as possible. From the leaked recording of the conversation with air-traffic control, it appears that no fuel emergency was ever declared. The transcript indicates a pilot saying only “it's in failure, uh, total... electrical and fuel”.

There is no clear evidence that the aircraft ran out of fuel through mismanagement. Alternative explanations include faulty fuel gauges, a fuel leak, or an issue with the complex fuelling system for the four-engined aircraft.

But there are echoes of a crash on the approach to New York JFK of a Colombian plane in 1990. Eighty-three people died when the Boeing 707 from Medellín crashed well short of the runway after running out of fuel.

Medellin Plane Crash Show all 17 1 /17 Medellin Plane Crash Medellin Plane Crash Logo of Brazilian football team Chapecoense at the site of the plane crash in a mountainous area outside the Colombian city of Medellin. Plane carrying Brazilian football team Chapecoense crashes in Colombia Rex Medellin Plane Crash Rescue workers carry the body of a survivor of a plane that crashed in La Union, a mountainous area outside Medellin, Colombia AP Medellin Plane Crash Rescue workers carry the body of a man from a plane that crashed outside Medellin, Colombia. The plane was carrying the Brazilian first division soccer club Chapecoense team that was on it's way for a Copa Sudamericana final match against Colombia's Atletico Nacional AP Medellin Plane Crash Medical staff waiting for survivors of the crashed plane carrying the Brazilian football team Chapecoense, at San Juan de Dios La Ceja Hospital, in La Ceja municipality, near Medellin Rex Medellin Plane Crash Medical staff from the San Juan de Dios hospital transfer 27-year-old Brazilian soccer player Alan Ruschel as he arrives to La Ceja in Colombia Rex Medellin Plane Crash 81 people, including the players of the Brazilian soccer club Chapecoense, crashed in a mountainous area outside Medellin as it was approaching the Jose Maria Cordoba airport EPA Medellin Plane Crash Medical staff from the San Juan de Dios hospital transfer Brazilian journalist Rafael Henze as he arrives at La Ceja in Colombia after surviving a plane crash EPA Medellin Plane Crash razil's Chapecoense player Helio Neto is helped by paramedics at the San Juan de Dios clinic in La Ceja. Traveling on the doomed airliner that crashed in Colombia overnight were the players and staff of a Brazilian football club about to complete a fairytale journey from unknowns to would-be South American champions Getty Medellin Plane Crash Rescue workers search at the wreckage site of a chartered airplane that crashed outside Medellin, Colombia AP Medellin Plane Crash A charter plane carrying the Chapocoense Real football team crashed in the mountains in Colombia late Monday, killing as many as 75 people, officials said Getty Medellin Plane Crash Rescuers gesture near the wreckage of the LAMIA airlines charter plane carrying members of the Chapecoense Real football team that crashed in the mountains of Cerro Gordo, municipality of La Union Getty Medellin Plane Crash Supporters of the Chapcoense FC gathering at the club in Chapeco, Brazil EPA Medellin Plane Crash Supporters of the Chapcoense FC gathering at the club in Chapeco, Brazil EPA Medellin Plane Crash People pay tribute to the players of Brazilian team Chapecoense Real who were killed in a plane accident in the Colombian mountains, at the club's Arena Conda stadium in Chapeco Getty Medellin Plane Crash Fans pay tribute to members of the Chapecoense team in front of the club headquarters, in the city of Chapeco Getty Medellin Plane Crash People pay tribute to the players of Brazilian team Chapecoense Real who were killed in a plane accident in the Colombian mountains, at the club's Arena Conda stadium in Chapeco Getty Medellin Plane Crash People pay tribute to the players of Brazilian team Chapecoense Real who were killed in a plane accident in the Colombian mountains, at the club's Arena Conda stadium in Chapeco, in the southern Brazilian state of Santa Catarina Getty

The investigation blamed “the failure of the flightcrew to adequately manage the airplane's fuel load, and their failure to communicate an emergency fuel situation to air traffic control”.