This proposal discusses the need for a monitor on commercial aircraft capable of detecting RF emissions over a broad dynamic range and an extremely wide electromagnetic spectrum. The security monitor has two purposes: (1) detect inadvertent RF emissions from passenger's portable electronic devices (PEDs) and (2)detect attacks from hostile subversives using high power microwave (HPM) RF weapons. The proposal discusses the synergistic combination of airline's advertisement of their vulnerability to hostile sources, the increased incidence and probability of domestic terrorist activity, the availability of HPM sources and their intrinsic characteristics that make them particularly attractive to subversives. A possible attack scenario is described in terms of the immediate results and the evidence that would be left for investigators. The consequences of ignoring the present vulnerability are explored, as well as the safety net provided by deployment of sensor systems. To optimize the value of the sensor system, it's usefulness in detecting non-hostile, inadvertent emissions from passenger's PEDs is also defined. Having such a system deployed in commercial aircraft will simultaneously allow passengers to operate non-interfering electronic systems freely while preventing and locating PEDs that are radiating interference.
