The writings — which some have interpreted as being either Arabic or Arabic-type symbols — appeared to have been done with a chemical process that reveals the text once an auxiliary power unit is turned on and heats up the outside skin of the aircraft, according to Feldman.
While it remains unclear how many aircraft are involved, the trend has reportedly increased in recent weeks.
Southwest Airlines has ordered its employees not to discuss the matter with the media, Feldman said.
In a statement to KNX 1070, Southwest said it is working with authorities to find those responsible for what the company called “vandalism”, but it’s not clear how many people are involved.
Both the Transportation Security Administration and Federal Bureau of Investigations is working with Southwest, but the airline denied this is a safety issue and would not provide any more details.
read more at KNX Los Angeles.
Why don't they just provide a photo of the alleged "mystery writing" to somebody who actually knows Arabic? It's not a big secret, folks.