Once, in the late 1980s, while at Buzzard's Point north of National Airport in Washington D.C., I myself had reviewed such a scenario in my mind. (The Channel 9 Eyewitness News title sequence used at the time on a local channel, vaguely suggested such an act.) I saw no common solution to such a problem, save to keep my mouth shut about the idea and the apparent hopelessness of its solution, in the hope of not giving some dumb goon a bad idea.
Much later, sometime within a year before writing this, I read with interest the news of a quite different scenario:
A small business jet is en route, at levels high enough to require pressurization of the cabin (or wearing an oxygen mask) to avoid anoxia or asphyxiation of occupants, and its autopilot is activated. Depressurization of the cabin occurs, slowly. The crew does not notice, and shortly all lose consciousness. The plane being on autopilot, it does not descend into denser air, so all on board die a little later. But the airplane has abundant fuel and the autopilot is guiding it at a steady altitude, so, like a ghost ship, it flys onward until fuel runs out, then crashes. Not only are all lives aboard lost, but the plane itself, of some value (I thought) is also destroyed: needless wastage, considering that for an hour or more it was flying itself! "Why couldn't it just land itself too, and save the owners or their insurance company a large financial loss?" I thought further.
Consider the concept of a 'dead man switch': A control device of some sort that senses a lack of (vital) activity on the part of the controller or pilot, and takes some appropriate action. If, say, the pilot, co-pilot, or flight engineer were left with the responsibility, once in the air, of occasinally activating a control, to apprise an airplane sub-system of their still being alive at the controls? (Having the system sense whether the control yoke, throttle, and other controls were being manipulated at all, would not do, since autopilot activation would to a great extent preclude such activity for considerable intervals.)
Then, if said control's time interval ran out, an alarm could sound (standard procedure in today's cockpit equipment in some cases). If the control were still not activated for a short time thereafter, the airplane system could assume incapacitation of flight personnel at least, or possibly of all people aboard.
Having determined this (and here's where it becomes a species of flight of the imagination), the system could
Either of these two scenarios, A-B1-C1, or A-B2, would save the monetary value of the airplane in the event of a flight crew or total incapacitation of those on board.
Thinking about it at the time, upon relection I did not think this as good an idea as it might be: the number of airline disasters of this type must surely be too rare for this approach, considering its expense, to be monetarily practical. That is, it would cost more than it would save.
In light of recent events, those of Terror Tuesday's hijackings and deliberate crashes, the way in which these cost not only an unmistakeably horrifying and abhorrent loss of very valuable lives, but also a great monetary loss, can be summarised as follows:
Item destroyed: Sufferer of loss: 1. Four large and expensive jet aircraft. Major airline companies. 2. Training cost of persons and personnel Major airline companies. on board. 3. Time and expense to insurance co.s, for Major insurers of several kinds. losses of people and equipment. 4. Destruction of business property and assets Several corporatins, of several nations. in the World Trade Center Towers especially. 5. National Airport's viability, owing to its Whoever financed the recent redesign of semi-permanent or permanent closing, in the National Airport's terminal. wake of these events. - and all businesses closed with the terminal, including taxis, shops, restaurants, airline ticket sales, the unemployment of those who used to work in all of these ... and so on, and on, and on!
The monetary loss consequent on this, to many corporations, companies, airlines, and the American government and people, may be expected to be very very large. Definitely more than any matter of advanced technology development, designed mainly upon existing and fully developed fields of advanced engineering, such as microprocessor/VLSI circuit design, AI systems, expert systems, computer data communication links, and electronic aircraft control systems.
The challenge also meets the requirements this old dictum: If we become like our enemy, we lose the war to some extent. The stupid goons who perpetrated this ghastly act of barbaric irrationality, were most likely suffering from 'too much blood in their veins, and a great lack of brains', to coin a phrase. (And by the way: Granted that their leader was Osama bin Laden, I would judge him, from his smugly simple manner combined with little tics or twitchy gestures, to be a complete nut, and a rather stupid one.)
Granted that criminality of this magnitude must be hunted down and completely quashed, it yet remains to say:
If we take the attitude that this act of brutality is best opposed by similar brutality, it is not only less practical, but also involves us in the same condition of 'too much blood in our veins, and a great lack of brains'. Americans have a tradition of technological solutions! It would be a shame if this tradition went down in a welter of violent and thoughtless moods and aims.
I stand solidly behind some such solution as this:
Instead of a simple 'dead man switch' arrangement, the same automated emergency control and landing system (or 'AECLS') which I have desribed above, could be adapted as a theft-and-misuse protection system, by altering the manner of its triggering - as well as, making its takeover of the airplanes controls total, complete, and not overrideable by even trained technical personnel while in the air (E.g., by placing all vital circuity that could be vandalized or altered to disable this AECLS by saboteurs or trained hijackers, in a place that cannot be reached during flight, not even by ripping off wall panels and so forth. - Not that you would expect an organization of moronic crooked nuts like the one involved in Terror Tuesday, to have members of advanced enough capability at a field like electronics!: Crashing an airplane can be done by any dum-dum, including a suicidal one.)
I admit that I have not made an advanced study of this: one man can only think of so much, and my acquaintance with the technologies involved, since my main area of expertise is PC and computing workstation technology and software, is limited. But consider this as a first draft of sorts, of the crucial idea:
Sensors of hydraulic pressure and attitude of the landing gear, upon takeoff, activates the system. (This prevents scenarios of anything other than ground-based hijacking or stealing of aircraft. And an airplane, while still on the ground, is a thing that can easily be prevented from taking off, without extensive damage to equipment or people on board: speeds before takeoff are low, and must build up before takeoff by a slow process.)
Upon takeoff, sensing a shut status of the cockpit door (which, indeed, ought to be armored or somewhat secure, even at expense of weight!), the AECLS issues a two-digit code on a readout. Cockpit personnel responsible for the AECLS' operation/activatino, memorize this code. At a given interval, 2 minutes at least and perhaps as much as 10 minutes, the system will require this code be entered in a small keypad, like that of a telephone. This constitues both a 'dead-man switch' function, and also aids security: in the event of a commotion/forcing of the cockpit door/gunshots/evident threat or occurence of violence, the system is activated by the entry of (even) one wrong digit.
Controls are locked at once. The AECLS takes over operations, changes transponder code to indicate violent hijacking, requests comm-link assistance/guidance more or less, and the airplane, ignoring any event within it short of major disabling of essential systems (which would cause a completely uncontrolled crash, as I see it - still a loss, but like unto those of Terror Tuesday), would proceed to land.
Airport emergency personnel would be awaiting, no doubt in force, the arriving aircraft. (As a slight additional detail, a self-sabotage such as draining away all hydraulic fluid from systems - which would require some overhaul but would also disable the aircraft from further misuse until it was secured.)
The hijacking would be a nuisance rather than an extaordinary and horrible disaster. And National Airport could reopen, we might well hope, and airplanes fly once again freely in Washington D.C. air space. - Without surrendering the normal conditions of our country and nation's capital to the acts of moronic terrorist nuts!
I sincerely hope that this core idea bears fruit, and voluntarily donate it free of charge to my nation.
In mourning for the many And for the damage seen by my own eyes that immemorial morning To the building where worked the best, bravest, And most decent people of my entire acquaintance September 11, 2001.[Russell Hess, Wednesday, September 19, 2001.]