### Question
How does TRANSPORTATION OF MAIL define 121 passenger aircraft?


### Answer
Under *39 U.S.C. § 5402*, **121 passenger aircraft** is defined as:

> 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**

