Pedro's mother is described as a middle-sized airplane. She tells her son to be safe when doing the mail route from Santiago to Mendoza.
Mama Plane lives with her family in an airport in Chile. Since neither her nor her husband could do the mail route due to her high oil pressure leaving her unable withstand higher altitudes, her son Pedro must fly to Mendoza, Argentina to do the task. Pedro's mother teaches her son to be safe while on the route from Santiago to Mendoza by avoiding downdrafts, while her husband tells him to stay away from Aconcagua. Pedro then takes flight to do his task.
Later that night, Pedro's parents believe their son is lost during his first flight. However, it is found out that Pedro actually survived his encounter with Aconcagua and the mail Pedro brought is actually a postcard, making his parents proud as he feels satisfied of himself.