According to an interview with Gen. Gustavo Vargas, managing director of LaMia, the plan was to stop and refuel in Cobija, Bolivia, and then fly to Medellin. But they decided instead to fly direct to Bogota for the stop. For some reason, they carried on to Medellin.
Director de la aerolínea LaMia habla sobre accidente de Chapecoense - Justicia - ELTIEMPO.COM