Method and apparatus for covertly detecting and reporting a distress condition in a vehicle control cabin

A method of covertly detecting and reporting a distress condition in a control cabin of a vehicle, the cabin having designated areas expected to be occupied by respective operators under normal operating conditions of the vehicle. The method comprises (a) attaching to each operator a transponder tag configured to wirelessly transmit a response signal, unique to the operator to which it is attached, responsive to an interrogator signal; (b) wirelessly transmitting interrogator signals into the designated areas; (c) attempting to detect response signals, if any, from the transponder tags; and (d) if all of the response signals are concurrently not detected, then wirelessly transmitting a distress signal from the vehicle.