航空学

航空学	háng kōng xué	aviation science
航	háng	boat / ship / craft / to navigate / to sail / to fly
航空	háng kōng	aviation
空	kōng	empty / air / sky / in vain
空	kòng	to empty / vacant / unoccupied / space / leisure / free time
学	xué	to learn / to study / to imitate / science / -ology