The FAA is investigating a "close call" between a JetBlue flight and a Learjet that took off without clearance at Boston Logan International Airport on Monday night. An air traffic controller instructed the pilot of the Learjet to line up and wait on Runway 9 while the JetBlue Embraer 190 landed on Runway 4-Right, but the controller then instructed the crew to "go around". The FAA is reviewing the air traffic controller's response and taking steps to prevent similar incidents in the future.