IPA: /ʌnˈflaɪəbl/
KK: /ʌnˈflaɪəbl/
Something that cannot be flown or is impossible to fly.
The weather conditions were so bad that the aircraft was deemed unflyable.
Unflyable → It is formed from "un-" (meaning not) and "flyable" (from "fly" which comes from Old English "flēogan", meaning to move through the air). The word "unflyable" means not able to be flown or incapable of flying.
Think of 'not' ('un-') being added to 'flyable' — this helps you remember that 'unflyable' means something that cannot fly.