The two black boxes recovered from last month's fiery crash of a Boeing 737-200 leased by Cuba's national airline are now in Washington, D.C., where they are being analyzed at the National Transportation Safety Board's recorder lab.
But the cause of the May 18 crash that killed 112 people may not be known for many months.
Flight 0972, en route to Holguín in Eastern Cuba, went down in an agricultural field shortly after takeoff from Havana's José Martí International Airport. Four people survived the crash, but three later died of their injuries. It was one of the worst aviation disasters in Cuban history.
Eyewitnesses said it appeared one of the plane's engines was on fire and the airliner hit electrical lines before falling in the field.
The black box that recorded voices from the cockpit was recovered shortly after the crash in good condition, and the plane's flight data recorder was discovered the next week.
Carlos Radamés Pérez Andino, the vice president of Cuba's Civil Aeronautics Institute (IACC), and two Cuban investigators accompanied the two black boxes to the NTSB lab for download.
"All information about the investigation will be released by IACC, who leads the accident investigation," the NTSB said in a statement.
Cuban aviation officials have acknowledged that the cause of the crash may not be known for as long as a year. Sometimes the cause of an aviation accident isn't determined for 12 to 18 months afterward, according to the NTSB.
The 39-year-old Boeing aircraft, which Cubana leased from Global Air (Damojh), a Mexican company, arrived in Cuba less than a month before the crash, and Cuban authorities said that the Mexican firm was responsible for the maintenance of the plane.
While the investigation is ongoing, Mexico’s civil aviation authority has temporarily suspended the operations of Global Air, an aircraft leasing company.
The same plane had been barred from Guyanese airspace last year. Guyanese Civil Aviation Director Capt. Egbert Field told The Associated Press that the crew had been allowing dangerous overloading of luggage on flights to Cuba.
The NTSB often participates in investigations of foreign air crashes, depending on various factors such as whether a U.S. airline is involved or if the aircraft was manufactured in the United States.
The NTSB is participating in the investigation under the provisions of the United Nations' International Civil Aviation Organization. Both Cuba and the United States are members of the ICAO. Mexico is also taking part in the investigation because the pilots, who died in the crash, were certified there and the leasing company is based in Mexico.
Representatives from Boeing, Pratt & Whitney, which manufactured the engine, and the Federal Aviation Administration are assisting the NTSB with the investigation, and a U.S. team traveled to Cuba shortly after the crash.
While relations between Havana and Washington have become frosty during the Trump administration, technical cooperation has continued in areas such as civil aviation, environmental protection and law enforcement.
The only survivor of the crash is 19-year-old Mailén Díaz Almaguer, who is being treated at Calixto García Hospital in Havana.
Earlier this week, Granma, the newspaper of Cuba's Communist Party, reported that she was still in very serious condition, but is conscious, is no longer on a respirator and is responding favorably to treatment.
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