Since you are on the Internet, you are familiar with computers, and you probably know what "passwords" are. If you share a computer with someone else, or if you are in an office where others could possibly sit down at your computer, you probably have password protection active. It is a standard feature of ALL Windows computers and most other computer platforms as well. Until you type in the necessary password, which generally means that YOU have to be sitting there, your screen stays dark and the keyboard is not functional.
Consider this situation: Each of the two pilot positions in an airliner has such password protection. Unless the person sitting in that seat inputs the correct password, the controls could not be operated and the instruments would appear blank. Before the pilots began their pre-flight checklist, they each had to type in a specific password (different for the two people). From then on the instruments and controls would act absolutely normally.
On long flights, soon after takeoff, the auto-pilot is nearly always engaged, to actually control the aircraft and keep it at a constant altitude and on a constant heading, until it is disengaged, usually shortly before landing. This means that, beginning only a few minutes after takeoff, the auto-pilot keeps the aircraft safe and level for the majority of the flight.
Now imagine ANY unexpected activity in the aircraft, whether an incident involving a passenger or flight attendant in the cabin, or even an unexpected entry of a passenger into the flight deck. Any of several "panic buttons" could immediately be activated by the pilots. They could specifically press a blanking button, similar to what you do with an office computer when you need to use the rest room, so no one could see what you had been working on while you were gone. Also, the pilots' seats could have weight sensors that had the same function, where if a pilot got up, his controls would instantly go blank. The aircraft would be perfectly safe, since the auto-pilot would keep if safe for hours to come, going on a straight and level course.
What could a potential hijacker or terrorist now do on the flight deck? The controls would be disconnected, and the instruments blank. If he should kill or disable the pilot, he still cannot alter the path of the aircraft, and cannot even disengage the auto-pilot. No matter what he would do, the aircraft would stay safe for several more hours.
The ONLY possibility of a hijacker or terrorist actually being able to change the flight path of the aircraft would have to involve the active participation of at least one of the two pilots. We all have absolute faith in ALL commercial pilots that none of them would ever participate in events like 9/11/01. So, the original pilots could not be killed or disabled, because at least one of them would have to participate in the terrorist activities, and we know they would never do that.
In the sick minds of terrorists, they could conceivably threaten, torture or kill the flight attendants and/or passengers, or even one of the flight crew. But the fact that the control of the aircraft's course required one actively participating pilot, ensures that a commercial aircraft could never again be used as a weapon.
I first realized all of this on 9/12/01, and very soon after that, I tried to give it to a number of Airlines, Boeing, the FBI, a number of Senators and Congressmen, and several network TV news organizations. It was obvious that the flying public would be terrified at the possibility of this happening again, and that the effect of huge numbers of people stopping their flying would be terrible to the airlines, to business, and to the economy, as well as to the overall confidence of our people. I tried VERY hard to let the "powers that be" know right away about this very quick and simple way to absolutely ensure that an aircraft could never be used as a weapon again.
Even more importantly, a Press Release by any airline that did this, or by any high authority in our government, would have done wonders to our National confidence right then. If such a spokesperson walked into the flight deck of an airliner with this modification, and the pilots, acting as though he was a terrorist, momentarily got up out of their seats and/or touched the disable button, any viewer would see the instruments instantly go blank. When our spokesman went over and sat down, he would show that the controls did not change anything, and he would point to the auto-pilot light that showed that everything was perfectly safe for now.
If the flying public saw such a demonstration, they would all immediately see how no terrorist could possibly alter the course of the aircraft, and they would not have been so terrified at boarding another airliner. They would also know that the airplane was destined to go level and straight for at least several hours, giving the passengers and crew a long time to figure out how they could deal with a few hijackers or terrorists. And even if this worst-case scenario occurred, and it took an hour to overcome the terrorists, and if the pilots had all been killed, if some flight attendant or passenger could use the radio headset, the ground could give the necessary password after calm had been re-established, and someone could then control the aircraft in order to land it safely.
First conceptualized, 9/12/01.
First described to various leaders, 9/14/01
First presented as this web-page, 11/9/01
( http://mb-soft.info/public4/index.html )
C Johnson, BA Physics, Univ of Chicago