Delta Airlines is a prominent US air carrier that isn’t a part of the current trend. The customers of the airline have been provided by their SkyMiles Loyalty Program from 1981 after which it was rebranded in the year 1995. Similar to the majority of services offered by airlines that are flexible customers of Delta’s program can accrue flight time through miles and improve their status in the Medallion Program. We’ll not get into the specifics of the benefits or terms for the scheme. However, it is important to know that the highest level is known as Diamond and it requires 125 000 miles. Simply If you are looking to upgrade to the the first-class class of Delta It is strongly recommended to check out delta free upgrade.