Counter hijacking system for an airliner

A counter hijacking system for an airliner having a fuselage with the fuselage including a cockpit separated from a passenger compartment by a bulkhead, an electrical system extending through the fuselage, and oxygen supply lines for delivering oxygen to the passenger compartment, comprising:

• a plurality of receivers disposed within the passenger compartment with the receivers spaced from each other at 15-foot intervals and interconnected to the electrical system;
• at least one portable transmitter carried by a flight attendant for transmitting a danger signal to the nearest receiver upon the determination that a dangerous condition is occurring in the passenger compartment;
• an alarm located in the cockpit and electrically connected to the receivers for sounding upon activation by the receivers;
• a knockout gas supply holding a volume of knockout gas with the knockout gas supply interconnected to the oxygen supply lines;
• a flow control valve for regulating the discharge of the knockout gas into the oxygen supply lines;
• a manually operable toggle switch for selectively opening and closing the flow control valve;
• and
• whereupon the transmission of the danger signal from the transmitter to the nearest receiver causes the alarm in the cockpit to sound so that a pilot or copilot can engage the toggle switch to open the flow control valve for allowing the discharge and conveyance of the knockout gas into and through the oxygen lines for introduction into the passenger compartment thereby rendering unconscious and incapacitating all individuals within the passenger compartment.