YOU SAID:
Air travel had entered a golden age.
INTO JAPANESE
航空旅行は黄金時代を迎えました。
BACK INTO ENGLISH
Air travel has entered its golden age.
INTO JAPANESE
空の旅は黄金時代を迎えています。
BACK INTO ENGLISH
Air travel is entering a golden age.
INTO JAPANESE
空の旅は黄金時代を迎えています。
BACK INTO ENGLISH
Air travel is entering a golden age.
That didn't even make that much sense in English.