then whos flying the plane

A mercenary takes on the job of tracking down a target on a plane but must protect her when they're surrounded by people trying to kill both of them.

A U.S. Marshal escorts a government witness to trial after he's accused of getting involved with a mob boss, only to discover that the pilot who is transporting them is also a hitman sent to assassinate the informant. After they subdue him, they're forced to fly together after discovering that there are others attempting to eliminate them.