Quintilian:
As long as the weather is OK and the passenger plane has visual contact and is slightly above and to the side of the the lighter aircraft there is no danger involved what so ever.
I trust that is your opinion. Have you had training in this procedure? Do you know whether SWA crews have been so trained?
I know the Air Force interceptor pilots have, plus they have ejection seats.
This is the governing federal regulation:
§ 91.111 Operating near other aircraft.
(a) No person may operate an aircraft so close to another aircraft as to create a collision hazard.
(b) No person may operate an aircraft in formation flight except by arrangement with the pilot in command of each aircraft in the formation.
(c) No person may operate an aircraft, carrying passengers for hire, in formation flight.