Federal authorities are investigating the defacing of several Southwest Airlines 737s with a special “invisible paint” that appears only after the plane is warmed with an auxiliary power unit.
Persistent reports that the scrawls were Arabic symbols or secret messages triggered fears of terrorism last week, but language authorities said later that the markings did not appear to be Arabic.
|An anonymous Southwest employee said the markings look like swords.|
Nevertheless, both the FBI and the Transportation Security Administration are investigating, and Southwest Airlines is conducting “an internal investigation,” a spokeswoman said.
Press reports say the marks appear to have been etched using a chemical process and become more prominent as the plane heats up.
The graffiti began appearing in February and has increased in recent weeks, the airline and press reports said.
In a statement Thursday, Southwest said the “markings have no affiliation to any known group or activity” and were being treated as vandalism. The airline did not say how many planes have been affected.
“Southwest takes this behavior very seriously, and we will continue to involve local and federal law enforcement agencies as needed until the situation is resolved,” the airline said, adding that aircraft safety “is in no way impacted” by the graffiti.
An internal Southwest memo obtained by ABC News said the airline was investigating the matter as an “internal vandalism issue.”
The paint appears toward the back of the 737 aircraft, but only after an auxiliary power unit is turned on, warming the underbelly, engines and landing gear. Most of the affected planes appear to be flying out of Los Angeles, reports said.
A Southwest employee told gawker.com that the markings “are on the exhaust pipe of the engines. Usually on the inboard side. And most of them are described as looking like swords. (picture an elongated “S” with a line crossing it toward one end.)”
Los Angeles radio reporter Charles Feldman, who first reported the story, said the incidents raise “disturbing questions about the security, because anybody who has the ability to write on an airplane and can get that close to do it, also has the ability to do other things to that aircraft.”