A grand jury has charged a man accused of plotting a suicide bomb attack at a Kansas airport where he worked as an avionics technician.
The three-count indictment charges Terry Loewen with attempted use of a weapon of mass destruction, attempted use of an explosive device to damage property and attempted material support to terror group al Qaida.
FBI investigators say Loewen was trying to take what he believed was a car bomb on to the tarmac at Wichita's Mid-Continent Airport when they arrested him last Friday.
In a letter to a relative that prosecutors say Loewen wrote two days before the planned attack, he said he expected to be martyred for Allah by the time the letter was read.
The 58-year-old Wichita man said his only explanation was that he believed in jihad, or holy war, for the sake of Allah and his Muslim brothers and sisters. He acknowledged that most Muslims in the US would condemn him, according to prosecutors.
If convicted Loewen faces up to life in prison on the most serious charge of attempted use of a weapon of mass destruction.
In the initial criminal complaint, authorities detailed an undercover sting in which Loewen and two FBI agents posing as conspirators hatched a plot to place a vehicle full of explosives at the airport.
Court documents said he timed the operation to cause "maximum carnage" and death.