### Question
How is the "121 passenger aircraft" defined?


### Answer
The term **121 passenger aircraft** is defined in *39 U.S.C. § 5402* as follows -

> an aircraft flying passengers on a city pair route that is operated under part 121

#### Citation:
  - *39 U.S.C. § 5402*
  - Heading: **PART V-TRANSPORTATION OF MAIL > CHAPTER 54-TRANSPORTATION OF MAIL BY AIR**

