A full investigation is expected to take months and will review everything from the 17-year-old aircraft's flight and maintenance history to the voice and instruments data in the black boxes recovered Tuesday at the crash site. (Photo: AP)

Medellin: The pilot of the chartered plane carrying a Brazilian football team told air traffic controllers he had run out of fuel and desperately pleaded for permission to land before crashing into the Andes, according to a leaked recording of the final minutes of the doomed flight.

In the sometimes chaotic exchange with the air traffic tower, the pilot of the British-built jet could be heard repeatedly requesting authorisation to land because of "fuel problems."

A female controller explained another plane had been diverted with mechanical problems and had priority, instructing the pilot to wait seven minutes.

As the plane circled in a holding pattern, the pilot grew more desperate. "Complete electrical failure, without fuel," he said in the tense final moments before the plane set off on a four-minute death spiral that ended with it slamming into a mountainside Monday night.

Just before going silent the pilot said he was flying at an altitude of 9,000 feet and made a final plea to land: "Vectors, senorita. Landing vectors."

The recording, obtained Wednesday by Colombian media, appeared to confirm the accounts of a surviving flight attendant and a pilot flying nearby who overheard the frantic exchange. These, along with the lack of an explosion upon impact, point to a rare case of fuel running out as a cause of the crash of the jetliner, which experts said was flying at its maximum range.

For now, authorities are avoiding singling out any one cause of the crash, which killed all but six of the 77 people on board, including members of Brazil's Chapecoense football team traveling to Medellin for the Copa Sudamericana finals – the culmination of a fairy tale season that had electrified football-crazed Brazil.

A full investigation is expected to take months and will review everything from the 17-year-old aircraft's flight and maintenance history to the voice and instruments data in the black boxes recovered Tuesday at the crash site on a muddy hillside. The U.S. National Transportation Safety Board was taking part in the investigation because the plane's engines were made by an American manufacturer.

As the probe continued, mourning soccer fans in Medellin and the southern Brazilian town of Chapeco, where the team is from, were converging on the two cities' soccer stadiums for simultaneous candlelight vigils. The six survivors were recovering in hospitals, with three in critical but stable condition, while forensic specialists worked to identify the victims so they could be transferred to a waiting cargo plane sent by the Brazilian air force to repatriate the bodies.

Alfredo Bocanegra, head of Colombia's aviation agency, said that while evidence initially pointed to an electrical problem, the possibility the crash was caused by lack of fuel has not been ruled out.

Planes need to have enough extra fuel on board to fly at least 30 to 45 minutes to another airport in the case of an emergency, and rarely fly in a straight line because of turbulence or other reasons.

Before being taken offline, the website of LaMia, the Bolivian-based charter company, said the British Aerospace 146 Avro RJ85 jetliner's maximum range was 2,965 kilometers (1,600 nautical miles) – just under the distance between Medellin and Santa Cruz, Bolivia, where the flight originated carrying close to its full passenger capacity.

"If this is confirmed by the investigators it would be a very painful because it stems from negligence," Bocanegra told Caracol Radio on Wednesday when asked whether the plane should not have attempted such a long haul.

One key piece to unlocking the mystery could come from Ximena Sanchez, a Bolivian flight attendant who survived the crash and told rescuers the plane had run out of fuel moments before the crash. Investigators were expected to interview her Wednesday at the clinic near Medellin where she is recovering.

"'We ran out of fuel. The airplane turned off,'" rescuer Arquimedes Mejia quoted Sanchez as saying as he pulled her from the wreckage. "That was the only thing she told me," he told The Associated Press.

Investigators also want to speak to Juan Sebastian Upegui, the co-pilot of an Avianca commercial flight who was in contact with air traffic controllers near Medellin's Jose Maria Cordova airport at the time the chartered plane went down.

In a four-minute recording circulated on social media, Upegui described how he heard the flight's pilot request priority to land because he was out of fuel. Growing ever more desperate, the pilot eventually declared a "total electrical failure," Upegui said, before the plane quickly began to lose speed and altitude.

"I remember I was pulling really hard for them, saying 'Make it, make it, make it, make it,'" Upeqgui says in the recording. "Then it stopped. ... The controller's voice starts to break up and she sounds really sad. We're in the plane and start to cry."

No traces of fuel have been found at the crash site and the plane did not explode on impact, one of the reasons there were six survivors.

However, there could be other explanations for that: The pilot may have intentionally dumped fuel in the hopes of reducing the risk of a fireball in a crash, or the aircraft could have suffered a fuel leak or other unexplained reason for losing fuel.

John Cox, a retired airline pilot and CEO of Florida-based Safety Operating Systems, said the aircraft's amount of fuel deserves a careful look.

"The airplane was being flight-planned right to its maximum. Right there it says that even if everything goes well they are not going to have a large amount of fuel when they arrive," said Cox. "I don't understand how they could do the flight non-stop with the fuel requirements that the regulations stipulate."</s>(CNN) Just before LaMia Flight 2933 crashed into a hillside near Medellin, Colombia, a crew member onboard told air traffic controllers, "The plane is in total electric failure and without fuel," according to two sources familiar with the investigation who heard audio recordings.

The conversations add new details to the final moments of the crash Monday that killed 71 people, including members of a Brazilian soccer team

They also add further evidence supporting investigators' suspicions that the jet had depleted its fuel during its charter flight from Santa Cruz, Bolivia, to Medellin.

Ana Maria holds a statue of Our Lady of Aparecida as she and her family mourn the loss of her son, journalist Guilherme Marques, during a ceremony in Rio de Janeiro on November 29.

Ana Maria holds a statue of Our Lady of Aparecida as she and her family mourn the loss of her son, journalist Guilherme Marques, during a ceremony in Rio de Janeiro on November 29.

Chapecoense supporters take part in a vigil at the team's stadium in Chapeco on Tuesday, November 29.

Chapecoense supporters take part in a vigil at the team's stadium in Chapeco on Tuesday, November 29.

The posts of a soccer goal are decorated with flowers while members of a Colombian army band rehearse for the tribute in Medellin on November 30.

The posts of a soccer goal are decorated with flowers while members of a Colombian army band rehearse for the tribute in Medellin on November 30.

A child with a Chapecoense flag attends a vigil at the team's stadium in Brazil on November 30.

A child with a Chapecoense flag attends a vigil at the team's stadium in Brazil on November 30.

Soccer players from Real Madrid and Cultural Leonesa observe a minute of silence in Madrid to pay tribute to those killed in the crash.

Soccer players from Real Madrid and Cultural Leonesa observe a minute of silence in Madrid to pay tribute to those killed in the crash.

Fans of Atletico Nacional -- the Colombian team that Chapecoense was traveling to play -- pay tribute to the fallen players at a stadium in Medellin, Colombia, on November 30.

Fans of Atletico Nacional -- the Colombian team that Chapecoense was traveling to play -- pay tribute to the fallen players at a stadium in Medellin, Colombia, on November 30.

Fans of the team hold their cell phones in the air during the tribute.

Fans of the team hold their cell phones in the air during the tribute.

Chapecoense supporters light flares during the stadium tribute on November 30. The soccer club, which has risen in the ranks in Brazilian soccer and now has a devoted national fan base, was set to play in the first leg of the South American Cup finals on Wednesday.

Chapecoense supporters light flares during the stadium tribute on November 30. The soccer club, which has risen in the ranks in Brazilian soccer and now has a devoted national fan base, was set to play in the first leg of the South American Cup finals on Wednesday.

Players from the Brazilian soccer team Chapecoense mourn their fallen teammates during a tribute at the team's stadium in Chapeco, Brazil, on Wednesday, November 30. A charter airplane carrying 77 people, including most players from Chapecoense, crashed near Rionegro, Colombia, on Monday, November 28. Seventy-one people were killed, officials said. Six survived: three players, two crew members and one journalist.

Players from the Brazilian soccer team Chapecoense mourn their fallen teammates during a tribute at the team's stadium in Chapeco, Brazil, on Wednesday, November 30. A charter airplane carrying 77 people, including most players from Chapecoense, crashed near Rionegro, Colombia, on Monday, November 28. Seventy-one people were killed, officials said. Six survived: three players, two crew members and one journalist.

The audio was published in Colombian media. Brazilian soccer squad Chapecoense was on its way to the Copa Sudamericana finals in Medellin. Three players, two crew members and one journalist survived, Colombian authorities said.

CNN reported Tuesday evening that investigators were considering a shortage of fuel as a significant contributor to Monday's crash, according to a person familiar with the early stages of the inquiry.

The lack of apparent fire damage among the wreckage of the of the British Aerospace Avro RJ85 strongly suggest the jet's fuel tanks were dry when it hit the ground.

Colombian media on Wednesday also published audio of an Avianca Airlines co-pilot, Juan Sebastian Upegui, relaying an eyewitness account as the doomed LaMia flight descended and lost contact with air traffic control.

Upedgui said the rapidly descending jet passed to the side of his own aircraft. "We even saw the plane lights as it was going down."

The pilot was listening to the radio and recalled that the crew of the LaMia aircraft did not declare to air traffic controllers a specific emergency regarding low fuel. In the audio, Upedgui said, "I remember that [my] commander asked, 'They have fuel problems and are not declaring an emergency?'"

Colombian Civil Aviation Authority spokeswoman Maria Cristina Pabon told CNN she could not confirm the authenticity of Upedgui's recollection or any air traffic control tapes that had been released by Colombian media.

But she added, "there are many coincidences -- it could be [true], however, officially the recordings are in custody and no one can touch them."

Bolivia's Public Works Ministry has launched an investigation into LaMia, a Bolivian charter airline, its owners, and executives.

The Civil Aviation Authorities of Bolivia suspended flying permits for both the airline's operator's certificate and the "permit to operate." Hours after the crash, Bolivian authorities assured that the plane's paperwork was up to date. The Civil Aviation National Registry approves licenses for aircrafts, issues certifications, and monitors legal issues that might affect aircrafts and their operating companies.

LaMia Airline's general manager, Gustavo Vargas Gamboa, and the head of Bolivia's Civil Aviation National Registry are father and son. Vargas Gamboa, the father, denied that the family ties allow him or his company any special benefits. "For this reason, I am not a partner, I'm a general manager," Vargas Gamboa said, explaining he does not own any company assets.

What causes a plane to run out of fuel?

Fuel exhaustion occurs when fuel is cut off from the engines, causing them to stop running. It can be caused by a number of factors including a fuel leak, internal icing, failure of the fuel pumps or gauges, or crew error managing the engine's use of fuel.

Electrical failure would also occur if an aircraft runs out of fuel. Electrical power is generated in-flight when the engines are running or through an auxiliary power unit on board. If those two sources fail, as they would without fuel, an aircraft's onboard batteries can power some systems for a short time.

Alfredo Bocanegra, director of the Colombia Civil Aviation Authority, said even though a preliminary investigation pointed to an electrical problem, the possibility the plane ran out of fuel has not been ruled out, CNN Italian affiliate ANSA reported.

However, Bocanegra said investigators would have to ascertain why the aircraft didn't have enough fuel, because it was just 5 miles away from the airport.

The Colombian Civil Aviation Authority declined to comment further on technical details. Photos released by authorities showed debris from the four-engine Avro RJ85 strewn across a hillside with no apparent charring among the wreckage.

Running out of fuel is "very, very rare in commercial aviation terms because there are so many checks and balances to make sure you have enough fuel on board," said Grant Brophy, an air safety investigator.

Exhausting all fuel aboard is not without precedent. Seventy-three people were killed in 1990 when a Boeing 707 flown by Colombian airline Avianca crashed near New York's John F. Kennedy International Airport after a flight from Medellin when it ran out of fuel, following an extended holding pattern and an aborted landing.

The cause was blamed on poor communication between the crew and air traffic control.

Scheduled commercial aircraft in the US are customarily flown with enough fuel to fly their planned route, plus enough extra fuel to reach the most distant of alternate airport options and 45 minutes of additional fuel as a safety margin to account for adverse wind and weather conditions.

Charter and international operators can operate under different rules, according to Phil Derner, an FAA licensed aircraft dispatcher and editor of the NYC Aviation news outlet.

Investigators will reconstruct the flight's final hours using data collected from the flight data and voice recorder, as well as maintenance and manufacturing records. The plane's so-called "black boxes" were recovered early Tuesday and were in excellent condition, according to Colombian aviation officials.

The charter flight took off from Bolivia's Viru Viru International Airport in Santa Cruz at 6:18 p.m. local time, according to air controller Manuel Palamas.

According to tracking data from FlightRadar24, the aircraft entered a racetrack-shaped holding pattern at around 20,000 feet before it crashed.

Air accident investigators in the United Kingdom, where the plane was manufactured, were also dispatched to the crash site to aid Colombian authorities in determining what happened.

The Avro series of regional jets were once mainstays of small US and European airlines that eventually retired them in favor of more efficient two-engine jets and propeller planes. The jet that crashed Monday flew with US regional carrier Mesaba Airlines when it was first delivered in 1999, according to the Aviation Safety Network.

According to a July 2016 report by Boeing, the Avro family of aircraft has suffered 14 accidents in which the aircraft was a total loss, including seven with fatalities. Monday's crash is the eighth due to noncriminal acts.

The crash marred what has been an otherwise exemplary year for aviation safety. Fatalities due to air crashes so far in 2016 are at less than half the 10-year average.</s>The pilot of the chartered plane carrying a Brazilian soccer team told air traffic controllers he had run out of fuel and desperately pleaded for permission to land before crashing into the Andes, according to a leaked recording of the final minutes of the doomed flight.

In the sometimes chaotic exchange with the air traffic tower, the pilot of the British-built jet requests permission to land because of "fuel problems" without making a formal distress call. A female controller explained another plane that had been diverted with mechanical problems was already approaching the runway and had priority, instructing the pilot to wait seven minutes.

As the jetliner circled in a holding pattern, the pilot grew more desperate. "Complete electrical failure, without fuel," he said in the tense final moments before the plane set off on a four-minute death spiral that ended with it slamming into a mountainside Monday night.

By then the controller had gauged the seriousness of the situation and told the other plane to abandon its approach to make way for the charter jet. It was too late. Just before going silent, the pilot said he was flying at an altitude of 9,000 feet and made a final plea to land: "Vectors, senorita. Landing vectors."

The recording, obtained Wednesday by Colombian media, appeared to confirm the accounts of a surviving flight attendant and a pilot flying nearby who overheard the frantic exchange. These, along with the lack of an explosion upon impact, point to a rare case of fuel running out as a cause of the crash of the jetliner, which experts said was flying at its maximum range.

For now, authorities are avoiding singling out any one cause of the crash, which killed all but six of the 77 people on board, including members of Brazil's Chapecoense soccer team traveling to Medellin for the Copa Sudamericana finals — the culmination of a fairy tale season that had electrified soccer-crazed Brazil.

A full investigation is expected to take months and will review everything from the 17-year-old aircraft's flight and maintenance history to the voice and instruments data in the black boxes recovered Tuesday at the crash site on a muddy hillside. The U.S. National Transportation Safety Board was taking part in the investigation because the plane's engines were made by an American manufacturer.

As the probe continued, mourning soccer fans in Medellin and the southern Brazilian town of Chapeco, where the team is from, held simultaneous stadium tributes to the victims. The six survivors were recovering in hospitals, with three in critical but stable condition, while forensic specialists worked to identify the victims so they could be transferred to a waiting cargo plane sent by the Brazilian air force to repatriate the bodies.

Alfredo Bocanegra, head of Colombia's aviation agency, said that while evidence initially pointed to an electrical problem, the possibility the crash was caused by lack of fuel has not been ruled out. Planes need to have enough extra fuel on board to fly at least 30 to 45 minutes to another airport in the case of an emergency, and rarely fly in a straight line because of turbulence or other reasons.

Before being taken offline, the website of LaMia, the Bolivian-based charter company, said the British Aerospace 146 Avro RJ85 jetliner's maximum range was 2,965 kilometers (1,600 nautical miles) — just under the distance between Medellin and Santa Cruz, Bolivia, where the flight originated carrying close to its full passenger capacity.

"If this is confirmed by the investigators it would be very painful because it stems from negligence," Bocanegra told Caracol Radio on Wednesday when asked whether the plane should not have attempted such a long haul.

One key piece to unlocking the mystery could come from Ximena Sanchez, a Bolivian flight attendant who survived the crash and told rescuers the plane had run out of fuel moments before the crash. Investigators were expected to interview her Wednesday at the clinic near Medellin where she is recovering.

"'We ran out of fuel. The airplane turned off,'" rescuer Arquimedes Mejia quoted Sanchez as saying as he pulled her from the wreckage. "That was the only thing she told me," he told The Associated Press.

Investigators also want to speak to Juan Sebastian Upegui, the co-pilot of an Avianca commercial flight who was in contact with air traffic controllers near Medellin's Jose Maria Cordova airport at the time the chartered plane went down.

In a four-minute recording circulated on social media, Upegui described how he heard the flight's pilot request priority to land because he was out of fuel. Growing ever more desperate, the pilot eventually declared a "total electrical failure," Upegui said, before the plane quickly began to lose speed and altitude.

"I remember I was pulling really hard for them, saying 'Make it, make it, make it, make it,'" Upeqgui says in the recording. "Then it stopped. ... The controller's voice starts to break up and she sounds really sad. We're in the plane and start to cry."

No traces of fuel have been found at the crash site and the plane did not explode on impact, one of the reasons there were six survivors.

However, there could be other explanations for that: The pilot may have intentionally dumped fuel in the hopes of reducing the risk of a fireball in a crash, or the aircraft could have suffered a fuel leak or other unexplained reason for losing fuel.

John Cox, a retired airline pilot and CEO of Florida-based Safety Operating Systems, said the aircraft's amount of fuel deserves a careful look.

"The airplane was being flight-planned right to its maximum. Right there it says that even if everything goes well they are not going to have a large amount of fuel when they arrive," said Cox. "I don't understand how they could do the flight nonstop with the fuel requirements that the regulations stipulate."

Goodman reported from Bogota. Associated Press writers Alba Tobella in Bogota, Ben Fox in Miami, Peter Prengaman in Rio de Janeiro and Dave Koenig in Dallas contributed to this report</s>A look at how fuel may have played a role in the crash of a charter flight approaching Medellin, Colombia, that killed all but six of the 77 people on board:

PRE-FLIGHT: Authorities have not released the flight plan for the jet operated by LaMia, a Bolivia-based charter company, but aviation experts say international regulations require enough extra fuel to fly at least 30 to 45 minutes to divert to another airport in case of emergency. Pilots also calculate the actual consumption of fuel during the flight and rarely get into a position that requires them to use reserves. The BAE 146 Avro RJ85 jet’s maximum range was 2,965 kilometers (1,600 nautical miles). That is just under the distance between Medellin and Santa Cruz, Bolivia, where the plane took off at almost full capacity.

FLIGHT AND APPROACH: A BAE 146 Avro RJ85 holds about 21,000 pounds of fuel. It burns fuel at a rate of 4,500-5,000 pounds an hour. The flight was in the air for about 4 hours and 20 minutes when air traffic controllers in Medellin put it into a holding pattern because another flight had reported a suspected fuel leak and was given priority.

CRASH: In the final minutes of the LaMia flight, the pilot of the jet can be heard repeatedly requesting permission to land due to a lack of fuel and a “total electric failure,” according to a leaked recording. The recording, obtained by several Colombian media outlets, seem to confirm the accounts of a surviving flight attendant and a pilot flying nearby who overheard the frantic pleas from the doomed airliner. In addition, there was no explosion upon impact, pointing to a scarcity of fuel.

Copyright 2016 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.</s>(CNN) Just before LaMia Flight 2933 crashed into a hillside near Medellin, Colombia, a crew member onboard told air traffic controllers, "The plane is in total electric failure and without fuel," according to two sources familiar with the investigation who heard audio recordings.

The conversations add new details to the final moments of the crash Monday that killed 71 people, including members of a Brazilian soccer team.

They also add further evidence supporting investigators' suspicions that the jet had depleted its fuel during its charter flight from Santa Cruz, Bolivia, to Medellin.

Ana Maria holds a statue of Our Lady of Aparecida as she and her family mourn the loss of her son, journalist Guilherme Marques, during a ceremony in Rio de Janeiro on November 29.

Ana Maria holds a statue of Our Lady of Aparecida as she and her family mourn the loss of her son, journalist Guilherme Marques, during a ceremony in Rio de Janeiro on November 29.

Chapecoense supporters take part in a vigil at the team's stadium in Chapeco on Tuesday, November 29.

Chapecoense supporters take part in a vigil at the team's stadium in Chapeco on Tuesday, November 29.

The posts of a soccer goal are decorated with flowers while members of a Colombian army band rehearse for the tribute in Medellin on November 30.

The posts of a soccer goal are decorated with flowers while members of a Colombian army band rehearse for the tribute in Medellin on November 30.

A child with a Chapecoense flag attends a vigil at the team's stadium in Brazil on November 30.

A child with a Chapecoense flag attends a vigil at the team's stadium in Brazil on November 30.

Soccer players from Real Madrid and Cultural Leonesa observe a minute of silence in Madrid to pay tribute to those killed in the crash.

Soccer players from Real Madrid and Cultural Leonesa observe a minute of silence in Madrid to pay tribute to those killed in the crash.

Fans of Atletico Nacional -- the Colombian team that Chapecoense was traveling to play -- pay tribute to the fallen players at a stadium in Medellin, Colombia, on November 30.

Fans of Atletico Nacional -- the Colombian team that Chapecoense was traveling to play -- pay tribute to the fallen players at a stadium in Medellin, Colombia, on November 30.

Fans of the team hold their cell phones in the air during the tribute.

Fans of the team hold their cell phones in the air during the tribute.

Chapecoense supporters light flares during the stadium tribute on November 30. The soccer club, which has risen in the ranks in Brazilian soccer and now has a devoted national fan base, was set to play in the first leg of the South American Cup finals on Wednesday.

Chapecoense supporters light flares during the stadium tribute on November 30. The soccer club, which has risen in the ranks in Brazilian soccer and now has a devoted national fan base, was set to play in the first leg of the South American Cup finals on Wednesday.

Players from the Brazilian soccer team Chapecoense mourn their fallen teammates during a tribute at the team's stadium in Chapeco, Brazil, on Wednesday, November 30. A charter airplane carrying 77 people, including most players from Chapecoense, crashed near Rionegro, Colombia, on Monday, November 28. At least 71 people were killed, officials said. Six survived: three players, two crew members and one journalist.

Players from the Brazilian soccer team Chapecoense mourn their fallen teammates during a tribute at the team's stadium in Chapeco, Brazil, on Wednesday, November 30. A charter airplane carrying 77 people, including most players from Chapecoense, crashed near Rionegro, Colombia, on Monday, November 28. At least 71 people were killed, officials said. Six survived: three players, two crew members and one journalist.

The audio was published in Colombian media. Brazilian soccer squad Chapecoense was on its way to the Copa Sudamericana finals in Medellin. Three players, two crew members and one journalist survived, Colombian authorities said.

CNN reported Tuesday evening that investigators were considering a shortage of fuel as a significant contributor to Monday's crash, according to a person familiar with the early stages of the inquiry.

The lack of apparent fire damage among the wreckage of the of the British Aerospace Avro RJ85 strongly suggest the jet's fuel tanks were dry when it hit the ground.

Colombian media on Wednesday also published audio of an Avianca Airlines co-pilot, Juan Sebastian Upegui, relaying an eyewitness account as the doomed LaMia flight descended and lost contact with air traffic control.

Upedgui said the rapidly descending jet passed to the side of his own aircraft. "We even saw the plane lights as it was going down."

The pilot was listening to the radio and recalled that the crew of the LaMia aircraft did not declare to air traffic controllers a specific emergency regarding low fuel. In the audio, Upedgui said, "I remember that [my] commander asked, 'They have fuel problems and are not declaring an emergency?'"

Colombian Civil Aviation Authority spokeswoman Maria Cristina Pabon told CNN she could not confirm the authenticity of Upedgui's recollection or any air traffic control tapes that had been released by Colombian media.

But she added, "there are many coincidences -- it could be [true], however, officially the recordings are in custody and no one can touch them."

What causes a plane to run out of fuel?

Fuel exhaustion occurs when fuel is cut off from the engines, causing them to stop running. It can be caused by a number of factors including a fuel leak, internal icing, failure of the fuel pumps or gauges, or crew error managing the engine's use of fuel.

Electrical failure would also occur if an aircraft runs out of fuel. Electrical power is generated in-flight when the engines are running or through an auxiliary power unit on board. If those two sources fail, as they would without fuel, an aircraft's onboard batteries can power some systems for a short time.

Alfredo Bocanegra, director of the Colombia Civil Aviation Authority, said even though a preliminary investigation pointed to an electrical problem, the possibility the plane ran out of fuel has not been ruled out, CNN Italian affiliate ANSA reported.

However, Bocanegra said investigators would have to ascertain why the aircraft didn't have enough fuel, because it was just 5 miles away from the airport.

The Colombian Civil Aviation Authority declined to comment further on technical details. Photos released by authorities showed debris from the four-engine Avro RJ85 strewn across a hillside with no apparent charring among the wreckage.

Running out of fuel is "very, very rare in commercial aviation terms because there are so many checks and balances to make sure you have enough fuel on board," said Grant Brophy, an air safety investigator.

Exhausting all fuel aboard is not without precedent. Seventy-three people were killed in 1990 when a Boeing 707 flown by Colombian airline Avianca crashed near New York's John F. Kennedy International Airport after a flight from Medellin when it ran out of fuel, following an extended holding pattern and an aborted landing.

The cause was blamed on poor communication between the crew and air traffic control.

Scheduled commercial aircraft in the US are customarily flown with enough fuel to fly their planned route, plus enough extra fuel to reach the most distant of alternate airport options and 45 minutes of additional fuel as a safety margin to account for adverse wind and weather conditions.

Charter and international operators can operate under different rules, according to Phil Derner, an FAA licensed aircraft dispatcher and editor of the NYC Aviation news outlet.

Investigators will reconstruct the flight's final hours using data collected from the flight data and voice recorder, as well as maintenance and manufacturing records. The plane's so-called "black boxes" were recovered early Tuesday and were in excellent condition, according to Colombian aviation officials.

The charter flight took off from Bolivia's Viru Viru International Airport in Santa Cruz at 6:18 p.m. local time, according to air controller Manuel Palamas.

According to tracking data from FlightRadar24, the aircraft entered a racetrack-shaped holding pattern at around 20,000 feet before it crashed.

Air accident investigators in the United Kingdom, where the plane was manufactured, were also dispatched to the crash site to aid Colombian authorities in determining what happened.

The Avro series of regional jets were once mainstays of small US and European airlines that eventually retired them in favor of more efficient two-engine jets and propeller planes. The jet that crashed Monday flew with US regional carrier Mesaba Airlines when it was first delivered in 1999, according to the Aviation Safety Network.

According to a July 2016 report by Boeing, the Avro family of aircraft has suffered 14 accidents in which the aircraft was a total loss, including seven with fatalities. Monday's crash is the eighth due to noncriminal acts.

The crash marred what has been an otherwise exemplary year for aviation safety. Fatalities due to air crashes so far in 2016 are at less than half the 10-year average.</s>The pilot of the chartered plane carrying a Brazilian soccer team told air traffic controllers he had run out of fuel and desperately pleaded for permission to land before crashing into the Andes, according to a leaked recording of the final minutes of the doomed flight.

In the sometimes chaotic exchange with the air traffic tower, the pilot of the British-built jet could be heard repeatedly requesting authorization to land because of "fuel problems." A female controller explained another plane had been diverted with mechanical problems and had priority, instructing the pilot to wait seven minutes.

As the plane circled in a holding pattern, the pilot grew more desperate. "Complete electrical failure, without fuel," he said in the tense final moments before the plane set off on a four-minute death spiral that ended with it slamming into a mountainside Monday night.

Just before going silent the pilot said he was flying at an altitude of 9,000 feet and made a final plea to land: "Vectors, senorita. Landing vectors."

The recording, obtained Wednesday by Colombian media, appeared to confirm the accounts of a surviving flight attendant and a pilot flying nearby who overheard the frantic exchange. These, along with the lack of an explosion upon impact, point to a rare case of fuel running out as a cause of the crash of the jetliner, which experts said was flying at its maximum range.

For now, authorities are avoiding singling out any one cause of the crash, which killed all but six of the 77 people on board, including members of Brazil's Chapecoense soccer team traveling to Medellin for the Copa Sudamericana finals — the culmination of a fairy tale season that had electrified soccer-crazed Brazil.

A full investigation is expected to take months and will review everything from the 17-year-old aircraft's flight and maintenance history to the voice and instruments data in the black boxes recovered Tuesday at the crash site on a muddy hillside. The U.S. National Transportation Safety Board was taking part in the investigation because the plane's engines were made by an American manufacturer.

As the probe continued, mourning soccer fans in Medellin and the southern Brazilian town of Chapeco, where the team is from, were converging on the two cities' soccer stadiums for simultaneous candlelight vigils. The six survivors were recovering in hospitals, with three in critical but stable condition, while forensic specialists worked to identify the victims so they could be transferred to a waiting cargo plane sent by the Brazilian air force to repatriate the bodies.

Alfredo Bocanegra, head of Colombia's aviation agency, said that while evidence initially pointed to an electrical problem, the possibility the crash was caused by lack of fuel has not been ruled out. Planes need to have enough extra fuel on board to fly at least 30 to 45 minutes to another airport in the case of an emergency, and rarely fly in a straight line because of turbulence or other reasons.

Before being taken offline, the website of LaMia, the Bolivian-based charter company, said the British Aerospace 146 Avro RJ85 jetliner's maximum range was 2,965 kilometers (1,600 nautical miles) — just under the distance between Medellin and Santa Cruz, Bolivia, where the flight originated carrying close to its full passenger capacity.

"If this is confirmed by the investigators it would be very painful because it stems from negligence," Bocanegra told Caracol Radio on Wednesday when asked whether the plane should not have attempted such a long haul.

One key piece to unlocking the mystery could come from Ximena Sanchez, a Bolivian flight attendant who survived the crash and told rescuers the plane had run out of fuel moments before the crash. Investigators were expected to interview her Wednesday at the clinic near Medellin where she is recovering.

"'We ran out of fuel. The airplane turned off,'" rescuer Arquimedes Mejia quoted Sanchez as saying as he pulled her from the wreckage. "That was the only thing she told me," he told The Associated Press.

Investigators also want to speak to Juan Sebastian Upegui, the co-pilot of an Avianca commercial flight who was in contact with air traffic controllers near Medellin's Jose Maria Cordova airport at the time the chartered plane went down.

In a four-minute recording circulated on social media, Upegui described how he heard the flight's pilot request priority to land because he was out of fuel. Growing ever more desperate, the pilot eventually declared a "total electrical failure," Upegui said, before the plane quickly began to lose speed and altitude.

"I remember I was pulling really hard for them, saying 'Make it, make it, make it, make it,'" Upeqgui says in the recording. "Then it stopped. ... The controller's voice starts to break up and she sounds really sad. We're in the plane and start to cry."

No traces of fuel have been found at the crash site and the plane did not explode on impact, one of the reasons there were six survivors.

However, there could be other explanations for that: The pilot may have intentionally dumped fuel in the hopes of reducing the risk of a fireball in a crash, or the aircraft could have suffered a fuel leak or other unexplained reason for losing fuel.

John Cox, a retired airline pilot and CEO of Florida-based Safety Operating Systems, said the aircraft's amount of fuel deserves a careful look.

"The airplane was being flight-planned right to its maximum. Right there it says that even if everything goes well they are not going to have a large amount of fuel when they arrive," said Cox. "I don't understand how they could do the flight nonstop with the fuel requirements that the regulations stipulate."

Goodman reported from Bogota. Associated Press writers Alba Tobella in Bogota, Ben Fox in Miami, Peter Prengaman in Rio de Janeiro and Dave Koenig in Dallas contributed to this report</s>A look at how fuel may have played a role in the crash of a charter flight approaching Medellin, Colombia, that killed all but six of the 77 people on board:

PRE-FLIGHT: Authorities have not released the flight plan for the jet operated by LaMia, a Bolivia-based charter company, but aviation experts say international regulations require enough extra fuel to fly at least 30 to 45 minutes to divert to another airport in case of emergency. Pilots also calculate the actual consumption of fuel during the flight and rarely get into a position that requires them to use reserves. The BAE 146 Avro RJ85 jet's maximum range was 2,965 kilometers (1,600 nautical miles). That is just under the distance between Medellin and Santa Cruz, Bolivia, where the plane took off at almost full capacity.

FLIGHT AND APPROACH: A BAE 146 Avro RJ85 holds about 21,000 pounds of fuel. It burns fuel at a rate of 4,500-5,000 pounds an hour. The flight was in the air for about 4 hours and 20 minutes when air traffic controllers in Medellin put it into a holding pattern because another flight had reported a suspected fuel leak and was given priority.</s>The pilot of the chartered plane carrying a Brazilian soccer team told air traffic controllers he had run out of fuel and desperately pleaded for permission to land before crashing into the Andes, according to a leaked recording of the final minutes of the doomed flight.

In the sometimes chaotic exchange with the air traffic tower, the pilot of the British-built jet could be heard repeatedly requesting authorization to land because of "fuel problems." A female controller explained another plane had been diverted with mechanical problems and had priority, instructing the pilot to wait seven minutes.

As the plane circled in a holding pattern, the pilot grew more desperate. "Complete electrical failure, without fuel," he said in the tense final moments before the plane set off on a four-minute death spiral that ended with it slamming into a mountainside Monday night.

Just before going silent the pilot said he was flying at an altitude of 9,000 feet and made a final plea to land: "Vectors, senorita. Landing vectors."

The recording, obtained Wednesday by Colombian media, appeared to confirm the accounts of a surviving flight attendant and a pilot flying nearby who overheard the frantic exchange. These, along with the lack of an explosion upon impact, point to a rare case of fuel running out as a cause of the crash of the jetliner, which experts said was flying at its maximum range.

For now, authorities are avoiding singling out any one cause of the crash, which killed all but six of the 77 people on board, including members of Brazil's Chapecoense soccer team traveling to Medellin for the Copa Sudamericana finals — the culmination of a fairy tale season that had electrified soccer-crazed Brazil.

A full investigation is expected to take months and will review everything from the 17-year-old aircraft's flight and maintenance history to the voice and instruments data in the black boxes recovered Tuesday at the crash site on a muddy hillside. The U.S. National Transportation Safety Board was taking part in the investigation because the plane's engines were made by an American manufacturer.

As the probe continued, mourning soccer fans in Medellin and the southern Brazilian town of Chapeco, where the team is from, were converging on the two cities' soccer stadiums for simultaneous candlelight vigils. The six survivors were recovering in hospitals, with three in critical but stable condition, while forensic specialists worked to identify the victims so they could be transferred to a waiting cargo plane sent by the Brazilian air force to repatriate the bodies.

Alfredo Bocanegra, head of Colombia's aviation agency, said that while evidence initially pointed to an electrical problem, the possibility the crash was caused by lack of fuel has not been ruled out. Planes need to have enough extra fuel on board to fly at least 30 to 45 minutes to another airport in the case of an emergency, and rarely fly in a straight line because of turbulence or other reasons.

Before being taken offline, the website of LaMia, the Bolivian-based charter company, said the British Aerospace 146 Avro RJ85 jetliner's maximum range was 2,965 kilometers (1,600 nautical miles) — just under the distance between Medellin and Santa Cruz, Bolivia, where the flight originated carrying close to its full passenger capacity.

"If this is confirmed by the investigators it would be very painful because it stems from negligence," Bocanegra told Caracol Radio on Wednesday when asked whether the plane should not have attempted such a long haul.

One key piece to unlocking the mystery could come from Ximena Sanchez, a Bolivian flight attendant who survived the crash and told rescuers the plane had run out of fuel moments before the crash. Investigators were expected to interview her Wednesday at the clinic near Medellin where she is recovering.

"'We ran out of fuel. The airplane turned off,'" rescuer Arquimedes Mejia quoted Sanchez as saying as he pulled her from the wreckage. "That was the only thing she told me," he told The Associated Press.

Investigators also want to speak to Juan Sebastian Upegui, the co-pilot of an Avianca commercial flight who was in contact with air traffic controllers near Medellin's Jose Maria Cordova airport at the time the chartered plane went down.

In a four-minute recording circulated on social media, Upegui described how he heard the flight's pilot request priority to land because he was out of fuel. Growing ever more desperate, the pilot eventually declared a "total electrical failure," Upegui said, before the plane quickly began to lose speed and altitude.

"I remember I was pulling really hard for them, saying 'Make it, make it, make it, make it,'" Upeqgui says in the recording. "Then it stopped. ... The controller's voice starts to break up and she sounds really sad. We're in the plane and start to cry."

No traces of fuel have been found at the crash site and the plane did not explode on impact, one of the reasons there were six survivors.

However, there could be other explanations for that: The pilot may have intentionally dumped fuel in the hopes of reducing the risk of a fireball in a crash, or the aircraft could have suffered a fuel leak or other unexplained reason for losing fuel.

John Cox, a retired airline pilot and CEO of Florida-based Safety Operating Systems, said the aircraft's amount of fuel deserves a careful look.

"The airplane was being flight-planned right to its maximum. Right there it says that even if everything goes well they are not going to have a large amount of fuel when they arrive," said Cox. "I don't understand how they could do the flight nonstop with the fuel requirements that the regulations stipulate."

Goodman reported from Bogota. Associated Press writers Alba Tobella in Bogota, Ben Fox in Miami, Peter Prengaman in Rio de Janeiro and Dave Koenig in Dallas contributed to this report</s>The pilot of the chartered plane carrying a Brazilian soccer team told air traffic controllers he had run out of fuel and desperately pleaded for permission to land before crashing into the Andes, according to a leaked recording of the final minutes of the doomed flight.

In the sometimes chaotic exchange with the air traffic tower, the pilot of the British-built jet requests permission to land because of "fuel problems" without making a formal distress call. A female controller explained another plane that had been diverted with mechanical problems was already approaching the runway and had priority, instructing the pilot to wait seven minutes.

As the jetliner circled in a holding pattern, the pilot grew more desperate. "Complete electrical failure, without fuel," he said in the tense final moments before the plane set off on a four-minute death spiral that ended with it slamming into a mountainside Monday night.

By then the controller had gauged the seriousness of the situation and told the other plane to abandon its approach to make way for the charter jet. It was too late. Just before going silent, the pilot said he was flying at an altitude of 9,000 feet and made a final plea to land: "Vectors, senorita. Landing vectors."

The recording, obtained Wednesday by Colombian media, appeared to confirm the accounts of a surviving flight attendant and a pilot flying nearby who overheard the frantic exchange. These, along with the lack of an explosion upon impact, point to a rare case of fuel running out as a cause of the crash of the jetliner, which experts said was flying at its maximum range.

For now, authorities are avoiding singling out any one cause of the crash, which killed all but six of the 77 people on board, including members of Brazil's Chapecoense soccer team traveling to Medellin for the Copa Sudamericana finals — the culmination of a fairy tale season that had electrified soccer-crazed Brazil.

A full investigation is expected to take months and will review everything from the 17-year-old aircraft's flight and maintenance history to the voice and instruments data in the black boxes recovered Tuesday at the crash site on a muddy hillside. The U.S. National Transportation Safety Board was taking part in the investigation because the plane's engines were made by an American manufacturer.

As the probe continued, mourning soccer fans in Medellin and the southern Brazilian town of Chapeco, where the team is from, held simultaneous stadium tributes to the victims. The six survivors were recovering in hospitals, with three in critical but stable condition, while forensic specialists worked to identify the victims so they could be transferred to a waiting cargo plane sent by the Brazilian air force to repatriate the bodies.

Alfredo Bocanegra, head of Colombia's aviation agency, said that while evidence initially pointed to an electrical problem, the possibility the crash was caused by lack of fuel has not been ruled out. Planes need to have enough extra fuel on board to fly at least 30 to 45 minutes to another airport in the case of an emergency, and rarely fly in a straight line because of turbulence or other reasons.

Before being taken offline, the website of LaMia, the Bolivian-based charter company, said the British Aerospace 146 Avro RJ85 jetliner's maximum range was 2,965 kilometers (1,600 nautical miles) — just under the distance between Medellin and Santa Cruz, Bolivia, where the flight originated carrying close to its full passenger capacity.

"If this is confirmed by the investigators it would be very painful because it stems from negligence," Bocanegra told Caracol Radio on Wednesday when asked whether the plane should not have attempted such a long haul.

One key piece to unlocking the mystery could come from Ximena Sanchez, a Bolivian flight attendant who survived the crash and told rescuers the plane had run out of fuel moments before the crash. Investigators were expected to interview her Wednesday at the clinic near Medellin where she is recovering.

"'We ran out of fuel. The airplane turned off,'" rescuer Arquimedes Mejia quoted Sanchez as saying as he pulled her from the wreckage. "That was the only thing she told me," he told The Associated Press.

Investigators also want to speak to Juan Sebastian Upegui, the co-pilot of an Avianca commercial flight who was in contact with air traffic controllers near Medellin's Jose Maria Cordova airport at the time the chartered plane went down.

In a four-minute recording circulated on social media, Upegui described how he heard the flight's pilot request priority to land because he was out of fuel. Growing ever more desperate, the pilot eventually declared a "total electrical failure," Upegui said, before the plane quickly began to lose speed and altitude.

"I remember I was pulling really hard for them, saying 'Make it, make it, make it, make it,'" Upeqgui says in the recording. "Then it stopped. ... The controller's voice starts to break up and she sounds really sad. We're in the plane and start to cry."

No traces of fuel have been found at the crash site and the plane did not explode on impact, one of the reasons there were six survivors.

However, there could be other explanations for that: The pilot may have intentionally dumped fuel in the hopes of reducing the risk of a fireball in a crash, or the aircraft could have suffered a fuel leak or other unexplained reason for losing fuel.

John Cox, a retired airline pilot and CEO of Florida-based Safety Operating Systems, said the aircraft's amount of fuel deserves a careful look.

"The airplane was being flight-planned right to its maximum. Right there it says that even if everything goes well they are not going to have a large amount of fuel when they arrive," said Cox. "I don't understand how they could do the flight nonstop with the fuel requirements that the regulations stipulate."

Goodman reported from Bogota. Associated Press writers Alba Tobella in Bogota, Ben Fox in Miami, Peter Prengaman in Rio de Janeiro and Dave Koenig in Dallas contributed to this report</s>Media playback is unsupported on your device Media caption The recording captures the final moments of the plane before it crashed

The plane which crashed in Colombia killing most of a Brazilian football side had run out of fuel, according to a leaked audio recording.

A pilot can be heard repeatedly requesting permission to land due to an electric failure and lack of fuel.

Only six of the 77 people on board the plane survived.

The team, Chapecoense, had been due to play a cup final in Medellin on Wednesday evening. Fans instead gathered to pay tribute.

Thousands of people carrying candles and wearing white filled the stadium where Chapecoense was to have played Atletico Nacional.

At the same time, Chapecoense fans held a tearful vigil at their home stadium in Chapeco, Brazil, which was draped in black ribbons. Both stadiums were filled to capacity.

Image copyright Reuters Image caption Atletico Nacional fans wore white to pay tribute to the Chapecoense players

Image copyright Reuters Image caption Chapecoense fans mourned victims of the plane crash at their stadium in Chapeco

What the audio tells us

The leaked conversations between the flight crew and a Colombian air traffic controller give a glimpse of the frantic, final moments of the doomed plane.

The pilot and can be heard warning of a "total electric failure" and "lack of fuel".

Just before the tape ends, he says he is flying at an altitude of 9,000ft (2,743m). The plane slammed into a mountainside near the Colombian city of Medellin late on Monday.

Image copyright EPA Image caption The flight's data recorders have been retrieved and are being examined

That there was no explosion when the plane came down also points to lack of fuel, with one Colombian military source telling the AFP agency its absence was "suspicious".

It is not known why the plane was out of fuel: whether it was because of a leak or because there was not enough on board.

Investigators have yet to announce any single cause for the crash and a full analysis is expected to take months.

What we know

Who was on board?

Chapecoense were flying to Medellin for what would have been the biggest match in their history - the final of regional tournament the Copa Sudamericana.

The team lost 19 players in the crash. Twenty journalists were also killed.

Among the survivors, Chapecoense said that two players remained in a critical but stable condition, while the club's goalkeeper had had one leg amputated and might still lose his other foot.

An injured journalist also remained in critical condition, the club said.

Another survivor, flight technician Erwin Tumiri, said he was still alive because he followed safety instructions.

"Many stood up and started shouting," he said. "I put the suitcases between my legs and assumed the brace position."

A team torn apart

What has the reaction been?

Three days of official mourning is under way in Brazil, with thousands of fans in the city of Chapeco massing in their home stadium to mark their loss.

Chapecoense directors say they expect up to 100,000 to attend collective funerals once all the bodies have been identified, most likely on Friday or Saturday.

"We're very anxious for the arrival of the bodies, to give them a last tribute, which they deserve. The city has stopped, waiting for that moment to come," said one supporter.

Image copyright Reuters Image caption Chapecoense fans have been gathering at their home stadium

There has been an outpouring of grief and support from the football world.

The team Chapecoense were due to play in the Copa Sudamericana, Atletico Nacional, have offered to concede the game so Chapecoense are declared winners, while leading Brazilian sides have asked the league to protect the side from relegation.

Many of football's most famous names, from Lionel Messi to Pele, have offered condolences.
The BBC reports that leaked audio recordings of air traffic tower tapes indicate that the LaMia Airlines flight was running out of fuel near the Colombian city of Medellin.