Delta Air Lines is studying new types of airplane tickets — this time in the premium cabins at the front of the plane ...

With 163 aircraft, it's also Delta's largest fleet type, and the carrier is the largest 737-900ER operator in the world. In the 2000s, Boeing developed the 737-900ER.

Delta Main Basic is the lowest of the three ticket types offered in economy class. There will also be Delta Main Classic and Delta Main Extra, the latter of which will offer extra air miles.