航空便: air mail

airmail; postal transport by airplane.

(formal) friend

to live in, to inhabit, to abide at, to dwell at

航空機: aircraft

(Kagoshima dialect) a letter, epistle (written message or note)

a letter, epistle (written message or note) / (archaic) a utility paper used for various purposes, such as for jotting down notes or for wrapping items

aircraft

he / distal demonstrative, something far off removed from both speaker and listener: that / boyfriend

to send; to dispatch / to see off, to take (somebody somewhere), to escort / to play back / (linguistics) to add okurigana / to pass the time / to see off a deceased person