Bepergian naik pesawat berapa ongkosnya?

English Translation

How long will it take by plane?

The mistranslation was caused by translating the Indonesian sentence from the Japanese sentence, and the English sentence was indirectly linked to the Indonesian sentence.
どれくらい in Japanese can mean either “how much” and “how long”. But “ongkos” means “cost” or “charge”, so the English sentence should be “how much”.