part of cell fate determination open tracheal system development epithelial cell fate determination, open tracheal system tracheal epithelial cell fate determination The cell fate determination process in which a cell becomes capable of differentiating autonomously into an epithelial cell within an open tracheal system regardless of its environment; upon determination, the cell fate cannot be reversed. Tracheal cells are set aside as 10 clusters of approximately 80 cells on each side of the embryo (termed tracheal placodes). An example of this is found in Drosophila melanogaster. biological_process GO:0007425 tracheal cell fate determination tracheal placode cell fate determination GO:0046846