YOU SAID:
I will go via next flight
INTO JAPANESE
次のフライトで行きます
BACK INTO ENGLISH
I will go on the next flight
INTO JAPANESE
次のフライトに行きます
BACK INTO ENGLISH
I will go to the next flight
INTO JAPANESE
次のフライトに行きます
BACK INTO ENGLISH
I will go to the next flight
That didn't even make that much sense in English.