Mankato (KMKO)-As Mankato Regional Airport prepares for the upcoming Minnesota Air Spectacular, area businesses are getting ready for a big boost in business.  Anna Thill of the Greater Mankato Convention and Visitors Bureau says the event could pump $5 million into the area's economy.  Up to 40,000 people are expected to watch the event this Saturday and Sunday.  Gates open at 9:00 am each day and the show starts at 11:00 am.