Brazilian authorities say two U.S. pilots flying a corporate jet over the Amazon last month were not following their approved flight plan when their plane collided with a Gol Airlines 737, resulting in the deaths of 154 people.
Officials says the flight plan indicated that the corporate jet would fly at an altitude of 11,278 meters from the city of Sao Jose dos Campos until it changed course over Brasilia.
They say that from Brasilia, the plane was supposed to drop 1,000 meters in altitude, and later climb 2,000 meters.
However, authorities say the plane kept to its original altitude, which was the same as that of the Gol Airlines plane. The U.S. pilots insist they had authorization to be at that altitude and had lost contact with air traffic controllers.
The Boeing 737 crashed after it collided in mid-air with the executive jet on September 29. The smaller plane made a safe emergency landing, while the Gol crashed into the jungle, killing all 154 people on board.
Brazilian air traffic controllers say equipment on the smaller plane, which would have reported its altitude to controllers, was not operating at the time of the accident.
Brazilian authorities have said the two pilots of the business jet must remain in the country while the investigation continues. Officials say they will interview the two pilots again to try to clear up inconsistencies regarding details about the crash.
Some information for this report was provided by AP and Reuters.