ABC15 in Phoenix, Arizona reports (video below) that Southwest Airlines is investigating what the company calls "unauthorized markings" that "typically appear as symbols or words tagged on the exterior of the aircraft.”
Southwest Airlines confirms that federal investigators are involved, but wouldn’t say exactly what was being written on the airplanes. Unnamed sources told ABC15 that the tagging appears to be Arabic. Some sources believe the tagging is being done by an employee, or employees, joking around.
One employee claimed that it's not uncommon for ground crews to write their names in dirt on the underbelly of planes, but said the recent markings were different.
In a memo from Southeast Airlines management, employees are asked to notify security if they witness taggings: “We need our employees to be aware of a situation that is taking place. Beginning in February, we received reports of markings on our aircraft, and recently these reports have increased."
“This issue is taken very seriously, and we will continue to work in cooperation with both local and federal law enforcement agencies until it is resolved. Any assistance you may be able to provide in determining who is responsible is appreciated."