Patapata Hikousen no Bouken

Jane's life changes dramatically after her mother's death and her father's remarriage to a woman with a son, William, who resents him. George and Jane share a dream of creating a flying machine, inspired by a supposed secret in the distant Asian deserts - a cerulean sand that allegedly has aerodynamic properties. However, George is executed for treason after searching for the sand, and William goes missing. Jane finds a cryptic letter with pale-blue sand that seems to defy gravity, and she sets out to find her brother, clear his name, and uncover the truth about the mysterious sand and George's supposed execution.