Guest Blog: The Uncrashable Airplane Is Within Reach


Are we asking the right questions with respect to the Germanwings tragedy? How do you teach a door to determine friend or foe? That is a tough one. Here is one that is not so tough; how do you teach an airplane not to fly into the ground? From the technical standpoint, that is easy. The real question to be asked is what is society ready for?

Is it ready for the airplane to be the last say in an argument with a pilot or other person? Or, are we going to start probing the minds of our already over-poked and prodded professional pilot population? How do you make an airline career even worse? Have a psychologist asking how your marriage is an hour prior to each flight?

On the other hand, if society is ready for the airplane to have the last say, this is an easy fix with today’s modern fly-by-wire airplanes. The airplane already has a digital map of the elevation for all of Earth’s terrain. We already have systems that provide an alert as to an impending intersection with the ground. Is it that far a stretch in technology to have the airplane fly away from that impending doom on its own?

No. In fact, the newest software load on F16s has just such a system. This system is constantly comparing the projected trajectory of the aircraft to the digital map of the Earth. In the event that it predicts an impending intersection, the aircraft assumes control and employs a very simple control law to avoid the terrain. In this case, it rolls wings level and pulls up to avoid a crash. Afterwards, the airplane releases the control back to the pilot.

This is one more step towards “carefree” flight. This is the idea that the pilot does not have to worry about bad things happening to the airplane. The pilot only need be concerned with the mission. In this case, combat. The pilot no longer needs to worry about overstressing the airplane or having it depart into uncontrolled flight. The envelope protection limits the G-loading, angle of attack and sideslip angle. Now add to that not having to worry about keeping track of where the ground is. Push as hard as you want. In a game of combat “chicken,” the F-16 pilot just aims at the mountain and the airplane pulls out just missing the terrain.

With some tweaking of the systems control laws to account for the lower roll rate and climb performance of an airliner, this could be implemented on today’s airplanes. Additional control laws could be installed that would not allow the airplane to fly in places where it should not fly, like over the southern Indian Ocean. This would have prevented MH 370 from vanishing, at least in that locale. It is very likely that this could be done to most airliners with a software only modification.

This is where the slippery slope starts to kick in. Because you have to now think of how an ill-willed pilot would defeat this new system. As an example, the airplane could not avoid the terrain if all the engines are shut off. It would glide down to a not so pleasant off-airport landing. Thus, the now final-authority computer, would also have to make a decision not to shut engines off or move fuel in a way not in the best interest of the airplane. There would be a significant number of flight critical commands that would have to be left, in the final evaluation, to the computer.

Where does it go from there? Connecting all the dots, you would see that a modern airplane would turn into a UAV with one exception: it would be manned. That is to say that the airplane could fly itself from takeoff to touchdown without any human intervention. Society may not be ready for flying in airplanes that have no on-board operators. Future pilots may end up more as systems operators. People that troubleshoot the computer when the computer fails. Or, when our own failure of imagination presents our well-trained computers with a situation that had not been anticipated.

We are in a time when technology is no longer the limiting factor in the equation, but rather public policy, perception and fear. The technology exists to have the airplane safeguard itself. It is much easier to teach an airplane to fly than to teach a door psychology.

Dr. Richard Pat Anderson is an ATP, CFI-AGMI, A&P, IA and a Professor of Aerospace Engineering.