The first flight of the prototype is scheduled for late next year and will be followed by series production.
The CDR was conducted this month by Embraer and the Brazilian air force.
"It was two intense weeks of presentations and discussions and we were very happy with the solutions presented by Embraer," said Engineer Col. Sergio Carneiro, manager of the Brazilian air force's KC-X Project. "We came out of these discussions convinced that the building of the prototypes can begin."
The KC-390 is a twin-jet airlifter and aerial refueler that is being built for the Brazilian air force. It has a range of 2,600 nautical miles with a payload of about 29,000 pounds.
"This is a great program landmark and we are proud of the result of our efforts to demonstrate the maturity of the project to the FAB," said Paulo Gastao Silva, director of the KC-390 program at Embraer. "We are certain that the KC-390 will be another big success of the proven combination of the well-defined FAB requirements and the solutions developed by Embraer to meet them."