Five percent, and decreasing. From the Washington Times, :
“They are flying on a relatively limited number of flights due to availability,” said Capt. Stephen Luckey, chairman of the national-security committee of the Air Lines Pilots Association, which represents 64,000 pilots.
The number of federal air marshals who protect planes from terrorist attacks is classified, and the Department of Homeland Security has refused to discuss it.
The sources said they are confident that terrorists already know the numbers based on open-source documents that can be found on the Internet, ongoing surveillance in airports and aboard planes, and in news reports.
At their request, information about specific flights or airports has been withheld.
Speaking on the condition of anonymity, the marshals, pilots and retired executive say there are fewer than 3,500 air marshals to protect 35,000 daily flights. Taking into consideration time off for sick leave, vacation and training, the sources say only 500 to 1,000 flights per day are protected.