actually that was probably it, a percieved threat to the nations tax collectors caused the QRF scramble)
HR, amusing as that might be, in fact not all the "passengers" who might make a pilot "squawk the squawk" want to bring down the whole of the western civilisation by flying headlong into a tower block for a world media spectacular, as per another 9/11.
Some of them might just hold a personal grudge, either at an organisation or even one individual, or want to arrive at one small but specific target by air. History has proved this to be the case, both in the fixed wing and helicopter environments. This is what I tried to put across on the other thread on this subject, but I gave up after I was branded as someone paranoid about terrorism, which I most definitely am not. But I
am aware that there might be other potential security threats to myself, my aircraft and passengers.
For example, one of my initial instructors (during my fixed wing training in the early 1970s) told a very graphic account of a "pleasure flight" booked by a man for his two young sons, in a Cessna 172. Once airborne, the man suddenly became very aggressive and tried to wrest control from my instructor. Turned out he had actually booked the flight so he could deliberately nose dive all of them into the ground. This was to kill them all, to permanently deprive his recently estranged wife of her sons.
After a struggle, the man was laid unconscious by the cockpit fire extinguisher being applied sharply to his left temple. The aircraft was landed safely, but obviously in traumatic circumstances.