Transport minister Seiji Maehara's controversial proposal floated this week to turn Tokyo's Haneda airport into a 24-hour international hub caused a firestorm of anger in Chiba Prefecture, where Narita International Airport is a key part of the economy.

The plan would mark a huge shift in the government's long-standing aviation policy that Narita is for international flights while Haneda handles domestic traffic.

Following are questions and answers about the two airports: