Author Archives: Chris

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About Chris

I have retired from my airline job but my passion is still flying. I want to write and teach as much as I can, as long as I can.

How Does an Airplane Fly?

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document.write(" serif;">Lift

An airplane stays up in the air because the wing pushes air down. It moves forward because the propellor or the jet engine pushes air back. We know when we drop something it falls to earth. We know that it is harder to ride a bike against the wind. So the wing and the propellor are acting against those natural forces. How does it all work?

Isaac Newton lived in the 18th Century. One day he was sitting under a tree, thinking about things. An apple fell from the tree and bonked him on the head. Rather than just curse, he thought harder. Something got that apple moving fast enough to make him want to say a bad word.

Newton wasn't starting from scratch. He was born in 1642, the same year Galileo died. Galileo, in his observations of the heavens, had come up with the idea that a moving body tends to keep moving – that it takes a force to stop it or make it change direction. He called this property inertia.

Inertia was a radical idea. Nineteen centuries before, Aristotle had described how a force was required to make an object move. If the force was removed the object would stop. Galileo's observations of the planets disagreed with Aristotle. Trying to make sense of what he saw, Galileo did experiments, dropping things from the Tower of Pisa and sliding blocks down inclined planes. He observed that if he made the inclined plane slippery, the blocks would slide further before stopping. Then he used the technique Einstein called a thought experiment, and what Aristotle called a reductio ad absurdum. If there is friction between the block and the inclined plane, and if that friction can be made less (by oiling the plane, for example), what would happen if the friction could be eliminated entirely? If it were zero?

Equilibrium

Here's the part that's counter-intuitive: a flying airplane is in a state of equilibrium. Cruising along, climbing or descending – all the forces acting on the airplane are in balance. The wings are pushing air down, creating lift; this exactly counterbalances the weight of the airplane, the pull of gravity which attracts the mass of the airplane to the much larger mass of the earth. Similarly the propellor (or fanjet) is pushing air back, exactly countering the drag caused by pushing the airplane through the air at speed.

Don't be concerned if this doesn't make sense to you. Making sense of it takes time, as is evidenced by history. Aristotle made a good start, back in 330 BC or so. He knew that you had to push on a mass to make it move. He also deduced that the force required was proportional to the movement. But he didn't make that next deductive leap to inertia – that took Galileo observing the motions of the planets through his telescope. The leap is a big one, because we have to think for awhile to come up with an example from our everyday lives. But they are there nonetheless: how about a curling stone, gliding with very little friction on an alley of ice? (The weight of the stone momentarily melts the ice; the stone is gliding on a temporary film of water). That stone keeps moving for a long time. With it in mind we can almost imagine Galileo's inertia and what Newton made of it – his first law of motion.

A body in uniform motion tends to remain in motion in a straight line unless acted upon by an external force.

Again, though, it takes a curious mind, building on the achievements of others, to take that extra step: Newton asked himself, in effect, what would happen to the curling stone if the resistance of the water/ice were not just small, but zero? The curling stone would just keep moving until it hit something!

Turning

A turning aircraft is not in equilibrium. Its flight path is not a straight line, but a curve. Looking at Newton's first law, we see that there must be another force involved, being applied so as to curve the flight path. In a car, we get that force by turning the steering wheel. If we turn hard enough we are pushed toward the door or the person next to us. We can feel it in the seat of our pants or our shoulder. There is a pull against the seat belt/shoulder harness. The lateral force is generated by the tires on the asphalt. On a bicycle or motorcycle we countersteer to make the bike lean into the corner. This is more closely analogous to an airplane. But still, an airplane has no asphalt to push against. Whence cometh this force?

The largest force generated by an aircraft is the lift from the wing. Remember: in equilibrium (steady flight) lift has to be equal to the aircraft's weight. So the pilot uses lift. He tilts the lift vector by banking the airplane like a bicycle or motorcycle. The horizontal component of lift is the force that curves the flight path.

IMG_0111

The airplane is blue. The white arrow is the wing's lift. The orange arrows are the lift divided into components so you can see how it all works. The vertical orange arrow holds the airplane up. The shorter horizontal arrow is the force causing the airplane to turn. The curving yellow arrow is the airplane's flight path.

Galileo observed the curved path of the planets and began to understand that there was a force causing the curve. Newton, still sore at the apple, saw that the force accelerating it into his head was the same force that curved the path of the planets. He proposed that masses (apple, planet earth, sun) attracted each other, and further, that the attraction was proportional to the product of the masses and inversely proportional to the square of the distance between them (F = mM/d2). It turns out Newton was right, but it was another century before Cavendish measured the force of gravity experimentally.

Lift, Again

We said that lift is produced when the wing pushes air down. Imagine that in an unthinking moment you jump from the stern of your rowboat (which you have just managed to land stern-to) to the dock. You instantly think better of it (although you are grateful you pushed off hard enough not to get wet) and look behind you. The boat is twelve feet away and still moving. That's action and reaction, Newton's third law of motion.

For every action there is an equal and opposite reaction.

Wings and propellors depend on this law. They push air down or back, and the reaction of the aircraft is to move up or forward.

How do wings push air down?

If you stick your hand out the car window at speed, you'll feel the force of the air against it. If you hold your hand flat, palm forward, your hand and arm will be pushed back. That's drag. Holding your hand palm down will produce less drag. You have made your hand into a more streamlined shape relative to the wind. Now try tilting your hand a little, holding the thumb side (leading edge) higher. You'll feel a force lifting your hand and arm up. That's lift. You could stick a one-by-six board out there and tilt it in the same way. If it wasn't ripped out of your hands, it would pull itself and your arms up to the top of the window.

The Bernoulli Digression

Stick your hand out of the window again, palm down and thumb into the wind. Now cup your hand slightly, moving your thumb down. (Your thumb is still pointing straight out, like your fingers, but your thumb, including the fleshy part in your palm where the first thumb bone is, has moved lower.) Now you will feel some lift, even without tilting your hand. By cupping your hand, you have made an airfoil shape. If you look at your hand you can see how an airfoil works. The oncoming air divides, somewhere on your thumb. It comes together again on the outside of your little finger. You can see that the air flowing over your hand follows a curve, and the air flowing under follows almost a straight line. The air flowing over your hand has further to go.

You can think of the air as 'stretching out' as it goes over the top of your hand. Many textbooks have pictures of this. The idea is that if two air particles start out together but divide at the wing leading edge, they stay above each other as they go their separate ways. Then they rejoin, arriving at the trailing edge of the wing at the same time. It is instinctive to imagine particles going over the top 'stretching out'. But if we move on to the the venturi (how a carburettor works – remember those?) the phenomenon is harder to imagine: air streaming through a tube which is constricted in the middle. The pressure in the constricted part is lower than the pressure at either end, just as the pressure on the top of the wing is lower.

Daniel Bernoulli (two generations after Newton) figured it out. He was a mathematician and described this process with equations. The equations invoked the Law of Conservation of Energy.

But we digress. It is not necessary to understand fluid mechanics to understand how an airplane flies. The Bernoulli Principle does help us make a flat board into an efficient wing. But remember that most aerobatic aircraft have symmetrical airfoils so they can fly just as well upside down. With these Bernoulli plays an even smaller part.

Basically, the wing pushes air down. That's really all you need to know.

Control

Where are we? We know the basics of why an airplane stays in the air and what makes it go. We have looked briefly at what makes it turn – we said that the pilot uses lift. But what else does the pilot do? How can he make the airplane climb and descend? Takeoff and land? Speed up and slow down?

Let's start with what makes it go straight: tail feathers. Like a bird or a dart, an airplane has weight up front and fins at the back. In the air (but not in outer space) all of these things move beak first. The heavy end of the dart with its sharp point will hit the target first (unless you're really new to the game). For slo-mo, think of a badminton bird falling with its nose toward the ground. The bottom line is that the nose points forward along the flight path (or nearly so). This is an inherent stability that kicks in before the pilot does anything.

Now imagine a small airplane. The engine, pilot and passengers are in the middle, near the front. This is where the weight is concentrated: the center of gravity. On each side the wings stick out; behind is the light aft end of the fuselage which holds the tail feathers: usually a vertical fin pointing up and a horizontal stabilizer sticking out each side. On the trailing edge of each of these surfaces are control surfaces – think of them as small wings hinged to the larger surfaces. The pilot moves these control surfaces using the stick and rudder.

In doing so he changes where the airplane points relative to the flight path. Remember “or nearly so” from two paragraphs ago? It is the pilot who chooses to point the airplane somewhere slightly different from forward along the flight path.

With the rudder pedals the pilot yaws the nose left or right. By pulling or pushing on the stick (or wheel or yoke) he pitches the nose up or down. And by moving the stick sideways (or turning the wheel or yoke) he moves the ailerons (on the trailing edge of the wing tips) and rolls the airplane left or right, banking like a motorcycle.

There is a fourth basic control: the throttle or thrust lever. With this the pilot controls how much air the propellor or fanjet pushes back. You can think of this as how much energy is being added to the system. That is the basics of it. Yes, when you push the throttle forward you are producing more thrust, so the airplane will climb or go faster until the increasing drag equals the thrust. If you pull the throttle back there will be less thrust and the airplane will slow down or descend, or both. But in each case you are adding more or less energy to the system.

Gliders

Wait, you say. How can a glider fly without an engine? Where does the energy come from?

The short answer is: from the winch, the tow plane, or the rising air in thermals. But if we want to think this through, we might also want to ask, where does the energy go?

Like most objects, an airplane can have kinetic energy, the energy arising from movement. Also like other objects it can have potential energy, which depends on its position in space. To simplify and make it more intuitive, we can limit the argument to its position relative to the earth. Is it on the ground or in the air? Like a ball or a case of beer, it takes energy to lift an airplane, to separate it from the surface of the earth. That energy is still there, as it is in a roller coaster rolling slowly over the top of the high point of the track.

Drop the ball and it will bounce. Drop the beer and you might have to go buy some more. But the roller coaster rolls over the top and down, accelerating as it descends, trading potential energy for kinetic energy. So it is with a glider or an airplane. Altitude above ground is potential energy. If the pilot uses the controls to select a descending flight path, that energy can be used as both lift and thrust – just enough thrust to keep the airplane at a good flying speed. That's a glide, and both airplanes and gliders can do it.

Some of you bright stars might say, wait – what about the Law of Conservation of Energy? If the airplane glides down and lands and rolls to a stop, it has no more energy. Where did it go?

The answer is: into thin air. Remember drag? Riding a bicycle into the wind? There is a lot of air out there so you don't notice it, but when you ride or run or even walk through the air you are expending energy to overcome the resistance of the wind and in doing so you are heating up the air! Friction, drag: they generate heat. Think of rubbing two dry sticks together.

Navigation

Imagine you are lazily watching a twig drifting down a placid stream. It is a peaceful scene. You are relaxed and your perception does its work. You sense the twig's slow movement from right to left.

Now imagine taking a movie (OK, a video) of the same scene. You take your camera home and open up the video in your editor. You look at it frame by frame. All the frames look exactly the same, except . . . yes! If you look closely the twig changes position. Not much from one frame to the next, but after say, a minute, it has moved almost across the frame. The twig is moving! It is changing position. It is drifting lazily downstream, moving with the water. It is moving slowly, at least relative to us on shore. We say it has a speed. But we also know it is moving downstream, from our right to our left. So it has not only a speed but also a direction, right to left . That combination of speed and direction is called velocity. Mathematically it is known as a vector.

Why are we talking about twigs?

Well, our airplane is a twig. It moves through the air that drifts over the surface of the earth. It was the same in the days of the square-rigged ships. Out of sight of land for months at a time, they moved by grace of the wind through currents and tides that had their own movement. To figure out where they were sailors used a sextant to find the elevation of the sun, moon and stars. They also used Dead Reckoning to calculate a new position from a known position (fix). We could do that with our twig if we knew the speed of the current in the stream. If the current flowed at one mph, for example, we could figure that if the twig is here now, then in an hour from now (barring mishaps) it will be a mile downstream.

Newton, Again

Isaac Newton developed the mathematics we still use for navigation today. (Leibniz did the same thing independently). It is called the calculus and is every math student's nightmare. I made it through second-year calculus with a D average. Nevertheless the elementary calculus that relates to airplanes (and ships and space-ships) has remained with me and been of enormous usefulness.

Basically Newton found a way to precisely quantify motion, even though speeds and directions might change. If he knew where the stream flowed, and at what speeds and directions through the rapids, over the falls, and eddying through the pond below the falls, he could calculate precisely where the twig would be at any moment. He did this by a process analogous to our video of the twig: if you shot the video in slow motion (many frames per second) you could analyze the motion of the twig with great accuracy. In effect, what Newton and Leibniz did was the ultimate slow motion: an infinite number of frames per second.

GPS and INS and IRS

At the end of the last century, GPS suddenly became a reality. A tiny receiver can listen to signals from satellites circling the globe and calculate a position on (or above) the surface of the earth to within a few meters. Here is a photo of the GPS Receiver I use with my iPad in the Bonanza:

IMG_0109

You can see how small it is – that's my pen next to it.

The GPS stores these positions (this is like the frames of our twig video) and then uses the calculus to find speed and direction. The process is called differentiation and is what our perception does as we lie on the bank of the stream watching the twig. It is how we perceive motion.

When I retired from airline flying (2004) only a few of the airplanes had GPS, and we flew no GPS approaches to find airports on cloudy days. Instead we used ADF and VOR and ILS, which send signals from ground-based stations.

Here is what my GPS was seeing while I stood on my back porch:

IMG_0110

I was standing still, so my speed was zero and I had no heading. (Actually I was looking south, but the GPS can't tell that until I start to move.)

Today in the Bonanza I use almost nothing but GPS. Using it I can fly an approach in cloud down to 300 feet above the runway.

When I was still flying airliners we used INS (and later the more accurate IRS) for our enroute navigation. These use Newton's calculus going backwards: they sense accelerations in three dimensions and calculate speed and position from there. Imagine riding a roller coaster with your eyes closed. (Those with delicate constitutions are excused). First you feel heavy, then you feel light. You know you are speeding up and slowing down. (It helps if you don't move your head.)

Your perception is recording those accelerations and correctly deducing that your speed is changing. This is the reverse of differentiation: it is called integration. Newton's mathematics lets us go back and forth from position to velocity to acceleration.

GPS Differentiation -->
Position

Velocity

Acceleration
Frames of Twig Video

Roller Coaster

<-- Integration INS, IRS

 Summing Up

An airplane flies because it has a wing that pushes air down and a propellor that pushes air back. The pilot has controls that can change how the airplane points relative to the flight path. That in turn influences the flight path itself – for example, the pilot makes the airplane turn by rolling into a bank, aiming the lift of the wings so that some of it is pulling toward the inside of the turn, curving the flight path. He can also add more energy to the system by pushing the throttle forward. Or he can throttle back and glide.

To navigate the pilot can look out the window for landmarks and use the compass and clock. Or she can use GPS. The best answer is to do both, because batteries can go dead.

The Future

If it makes you feel good to think about this stuff, I have great news: there's lots more! In fact it seems that the more interested you get, the more there is to discover. And if aviation turns out to be your thing, have no doubt that you will be needed. Because if flying through the air uses too much fuel some day, we will still need to get into orbit and fly around from there.

Flying in space will take even more mathematics (orbital mechanics, for a start). And here's another problem: Newton's laws (and his calculus) are deterministic. That means you can go back and forth, as we did in the table above. And if you take his equations to their logical conclusion, you can go back and forth in time, and everything that was and will be has already been determined.

But we no know that's no so, or not quite. If things get very small, so small they can't be divided – for example, a photon of light – they behave differently from the objects we know. Then we use another math: quantum theory. (Stand by, because you young people will see quantum computers in your lifetimes). If things get very big, like galaxies, or if we try to accelerate a space-ship to the speed of light, then we have to use Albert Einstein's Theory of Relativity.

And don't let anyone tell you pilots won't be needed. Remember Chewbacca, the Wookie pilot from Star Wars? He took the Millennium Falcon to warp speed by hand. Computers are going to be a big help, but in a way they give us more to learn. So if you love to fly you'll have to learn flying and math and computers and navigation in space and . . .

But that's just more fun!

Younger Every Day

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I flew her home Tuesday. She performed flawlessly. She gets compliments wherever she goes. Here she is in her new colours:

DSC_0066

John Goris at Purple Hill Air has done a beautiful job restoring her. He has also completely re-rigged her controls to factory specs. Now I can take my feet off the rudders at cruise and the ball is in the center. And she is about 5 knots faster!

I’m getting older but she looks like new.

Rule by Metric

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Survival?

In the grand scheme of things, there is not the slightest doubt that humanity can survive. The peril of the planet and the challenges of leaving it are not beyond our husbandry. But it will not be the market that saves us – it will be ourselves.

To this end, there is a heartening article in today's Sunday Times: Why You Hate Work. The authors have done surveys which, in a nutshell, find that employees (and management, too) are most productive when their needs are met in the workplace. What needs are these? The physical need of rest and renewal. Feeling valued and cared for. Being allowed to focus on the task, and thereby finding purpose and meaning in work. Feeling that their work has made a difference, however small. Surprised?

We are not machines. Our output is not proportional to time spent on the job. Our capacity for creation is huge and unknown, but it is delicate and must be given room to flower.

Our Metrics

Where have we gone astray? It's the metrics, stupid.

By worshipping the market we come to the conclusion that the purpose of enterprise is the bottom line. Managers define productivity as income or profit per employee, or worse, as hours worked per dollar of wages. It is any wonder that the phrase the working poor has made it into our modern vocabulary?

We are using hours and money to measure the value of work. Then we use the market to make our existential decisions for us.

This is not because we are evil. We are human and in trying to grasp our complicated selves we seize what is doable and ready to hand. And as to the larger decisions, we are overwhelmed and beg to be excused. For how often, in our daily lives, are we visited with silence, peace, and courage? It takes all of these to acknowledge the existential decisions that face humanity. Our humanity. Us.

Money is useful. Only by having some – in today's society, at least – can we make a space for thought. Money is a tool, a medium of exchange, and exchange is essential.

Money is also an abstraction, a practical means of evaluating both things and ourselves. But the value of things is debatable (that's why we need money or barter in the first place) and we ourselves are beyond value. And when we cede to the market we are putting our trust in an abstraction of an abstraction, a tool without form.

What Metric?

Let's go back to what is really essential: exchange.

Farmers a century ago did much of their work alone, but building a barn required co-operation. (That's where the phrase barn raising comes from). If I help my neighbour, he will help me in the really big jobs I can't do alone.

Today we have before us a really big job: the survival of humanity. No amount of management or regulation can achieve this. Nor can capital, in the way we think of it. Financial capital will of course be necessary, more than ever before, and the financial world would do well to refocus on its primary purpose. But the other capital – human capital – is more important by far.

Each of us, however poor or simple, has a light within. How can these small flames be kept burning? How can they be nurtured and combined to illuminate and power a larger purpose?

Not by demand. Not by fear. As in all things human, we give ourselves willingly when we feel valued – in fact we give willingly that which did not exist before we felt valued. It is how we treat each other that determines whether our gifts will flower or come to naught.

So it is with work. Our survival depends on each of us doing his best work. What metric will we use to value that?

Mission Statement

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Today we take an airline’s schedule for granted. We are surprised when a large snowstorm forces flight cancellations or when a line of thunderstorms causes delays. We regard the pilot’s job as routine, and that is the case much of the time.

It was not always so. In the early days airplanes could not vault over the Rockies as if the snow and granite weren't there. They could not shrug ice off their heated wings. They could not follow programmed profiles in four dimensions. Pilots had to fly these airplanes.

Seventy-five years ago Canada's national airline flew its first “transcontinental” mission: Montreal to Vancouver via Ottawa, North Bay, Kapuskasing, Winnipeg, Regina, and Lethbridge. The aircraft was a Lockheed 10A. I don't have a 10A or the resources to fly it, but I do have a Beech Bonanza, a single-engine aircraft of similar performance. Her name is Arcadia, after the fictional airline in my novel. Together we are going to fly that route this year. Our mission is to do again what the pioneers did: fly through Canadian weather at low altitude, evaluating the real risk and flying when we can, flying by hand.

Why?

To remember and celebrate that achievement of 1939, yes. To observe and celebrate how far airline flying has come since then – yes, that too. But there is more. Between then and now is a story, a story that includes rough weather and anxious moments. These advances and adventures are not always smooth sailing. There is risk, danger, and hard work. That is where the real story lies.

Although much remains in official records and memoirs, in news stories and film, much of the history of Canada's airlines has been lost. Many of the early pioneers have passed on, taking their stories with them. We could use their perspective now, as we face the coming shortage of fuel and pilots. Once again, there is rough weather ahead.

Flying is like living. Planning and good judgement are essential for survival. But once you're off the ground or out of the childhood home, it is no longer a rehearsal. The red light is on. You're live to air. Flying has been my trade now for forty-five years, and that live to air quality is still what gets my juices going.

Since young hotshot are not words which apply to me (I turn seventy this year), I have to make sure I am well prepared for this mission. I will be flying IFR (Instrument Flight Rules) and sometimes in IMC (Instrument Meteorological Conditions) without an autopilot (the Bonanza does not have one) and without a co-pilot. That can get pretty busy. But I do have WAAS GPS, an electronic PFD, and an iPad. The GPS lets us navigate anywhere and do an IFR approach at most airports. On the electronic PFD (Aspen 1000 Pro) I can set cleared altitudes and approach minima, just like I used to do on the Airbus. On the iPad I have the app ForeFlight, which acts as my electronic flight bag (charts and approach plates for all of North America) my moving-map display, and my weather briefing service, among other things. It is hooked up to a GPS and to a satellite weather link.

For the last three years I have been training for this mission. Written exams. Instrument rating renewal. Re-introduction to flying light aircraft. Aerobatic instruction. Working steadily toward regaining my Class II Instructor rating after forty-some years. And practical experience, of course. I have flown the Bonanza between Montreal and California. By this summer, God willing, it will have been two round trips.

Flying experience is measured in hours and in recent hours. These are handy because they are statistical, but they are not the whole story. Experience does not necessarily lead to competence. More important are real learning and practice. You can't perform a maneuver you don't know about, and you can't do it well until you have practiced it.

I know this from my own experience. I retired from airline flying at age sixty and didn't “touch a pole” for six and a half years. When I decided to come back to flying my performance was far from an acceptable standard, even with my 18,000 hours. With a valid instrument rating and my ATR, I was “qualified” to teach instrument and multi-engine flying, but lacked the recency, confidence, and knowledge to do it well. I had to go back to school.

Old dogs are reluctant to see the need for new tricks. Breaking through my crusty assumptions to teach me is not a job for the faint of heart. I have been fortunate to find teachers who will challenge me and move me along, almost against my will.

This burst of learning is a fragile thing. Old age is gaining on me. I know how the race ends. But Arcadia and I plan to fly the mission this summer of 2014, re-enacting the flight of 1939. Much of the detail of that flight has been lost, but we will re-create it by living it. It will be its own story, but it will have much in common with the lost story of 1939 – enough, I hope, to bring that story to life and bestow honour where honour is due.

Work and Words

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It is said that we form our thoughts in language. It follows that words are important – that their meaning, changing through time and usage, also affects our thoughts.

The News

Last Friday's “jobs numbers” have left me thinking about words as well as about jobs. What is a job? Is it what we need? What we want?

Job creation last month (December, 2013) was the lowest in some time, and yet the unemployment rate went down. Why? Because fewer people were seeking jobs. Why? Because they are discouraged? Too old? Too young? Uneducated? Can survive some other way?

Yes. Yes to all of these and more. But we must also consider some of the employed: the working poor.

Employees of fast food outlets and big box stores typically earn the minimum wage and are hired as temporaries without benefits. Even though they work full time in their “temporary” position, their annual salary puts them below the poverty line. Their full-time job can't support a family. They survive with the help of food stamps, medicaid, and good luck. A company gets cheap labour and the taxpayer foots the bill for the small help that the working poor receive. The profits from this system go to (at best) shareholders or (more likely these days) to a small group of stakeholders.

The Writers' Almanac

Garrison Keillor ends his Writers' Almanac with a sign-off which feels like a sending-forth: “Be well, do good work, and keep in touch.” Because I hear the Writers' Almanac several times a week and have been doing so for years, Garrison's sign-off has lodged in my head, a touchstone for reflection.

I think about it more often than I hear it on the air. It takes on the form of a prescription, even a prayer.

I think about the order: be well, do good work, keep in touch.

First we must have health. We must have food and shelter; we must be able to survive.

Next – perhaps surprisingly – we need work. We must employ our God-given gifts for good, for making or accomplishing something, for making a difference, however small. This is our purpose. It is why we are here. It is what will bring meaning to our lives and comfort to our deathbed.

Finally, we must “keep in touch.”

I have struggled long with this one. Why is it last? How can we say that love, family, friendship and companionship, social and political action, and even faith and religion must come last? This seems to go against all teachings and norms.

But wait. Can a person who is not whole truly love another? Can a person who has yet to find meaning feed his family or bring energy to a friendship? Can he be a responsible citizen?

These are cruel thoughts. One could follow them into a judgment of the sad, the poor, and the simple. Thankfully, Pope Francis said, “Who am I to judge?”, so I can accept the cruelty of my thoughts as I accept the cruelty of nature, and move toward the lesson, toward what I have learned from Garrison's sending-forth: work is important.

Work

So what is work?

Etymology, the study of words, can sometimes remind us of meanings which, although to all appearances lost, still hover ethereally at the fringes. I was surprised to find, for example, that a Greek word for work is ergon, from which we get urge. Can this be a clue? Is work an urge, something that we must do? Baudelaire said  “Work is less boring than amusing oneself”, calling into question the primacy of play.

Jobs

In contrast, the etymology of job leads us to gob, a cartload, a piece of work. A piece of work that is low, mean, temporary, and lucrative. Petty, piddling work. A piece of chance work. The sense of job as work done for pay dates back to the 1650's.

Conclusion

Etymology can lead us through histories of meaning. Current usage can inform us about today's pressures and politics and give us perspective on our own thinking.

But all writers, consciously or not, try to re-shape words, to use them in ways which expand their meaning.

Drawing on the Greeks, Baudelaire, and Garrison Keillor, I would honour work as what we must do: use our gifts for good, however small. If we can feed our families through this work, so much the better. We are lucky indeed.

If (at least for the moment) we cannot, then perhaps we must find a job, a piece of work which is low but lucrative.

But I pray that as individuals and as a society we may see the difference. And I pray that more of us may find fulfillment in work. It will make a difference for humanity.

The Lost Apprentice

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Despite our words of concern for education and training, our workforce is racing toward the cliff of incompetence. Even though innovation and specialization have brought us marvelous new tools, basic skills are vanishing, collateral damage from a squeeze on labour. How? In a word, the apprentice has gone missing.

One company (BMW in South Carolina), experiencing first-hand the dearth of skilled labour, has set up an apprenticeship system. But there is resistance. After all, from skilled labour flows empowered labour and unions. From there a slippery slope leads to socialism and communism. Or so goes political thought.

Yes, we are on a slope, but the destination is not an 'ism'. It is incompetence.

My trade is flying airplanes, so I'll stick to what I know. But look around in your own trade or profession and you may see examples of what I'm talking about. Are you passing on your knowledge? Are there barriers to doing so? Will the young people taking up your mantle be able to learn from your mistakes and those of your teachers? Or will they repeat those mistakes? Will they master the new tools that arrive, it seems, every day? Or will they hide behind them, shirking responsibility simply because they are afraid, deep in their gut, that they can't do the job?

I was lucky. I joined the airline in the right seat of the DC-9 and learned fast. I flew with captains who took their teaching responsibilities seriously. I particularly remember Ike Jones, a great, generous, good-natured Newfoundlander. He was Master to my Apprentice. He taught me and I have never forgotten.

Learn By Doing

Lee Kang Kuk (the Asiana 214 Trainee Captain) was not so lucky. He was an “experienced” pilot, a captain on Airbus aircraft transitioning to the B-777. I put experienced in quotes because although he had thousands of hours of flying, he found the prospect of doing a visual approach “very stressful.” To me this seemed nonsensical until I began to think about it. I thought about the Asiana First Officer who told the investigation he had been flying the A320 for three years and had never landed the airplane manually.

I thought of myself. After retirement from the airline I didn't fly for 6½ years. I had to get training, pass exams and tests, and retrain myself. This year I have been working with Andrew Boyd, a Class I instructor, trying to get my skills up to where I can get my Class II instructor rating back. It has been a lot of joyful work. But I see even more than I did six months ago that we all learn by doing. Practice, practice, practice. Lee's airline recommends that its pilots fly their planes manually as little as possible.

Lee didn't have a chance. He said, “(it is) very difficult to perform a visual approach with a heavy airplane.” Horsefeathers. It is actually harder with a very light airplane. What is difficult (if not impossible) is to fly any maneuver without practice.

History Repeats Itself

Fifty years ago last month an Air Canada DC-8 crashed at Ste.Thérèse, Québec. Last month a Boeing 737 crashed at Kazan, Russia. The DC-8 hit the ground at 55° nose down. The B-737 hit the ground at 75° nose down.

It is unlikely that the young pilots in Russia knew of the DC-8 accident. After all, it happened before they were born. What possible relevance could it have for them?

Well, we know from the evidence so far that they were not prepared for the missed approach they tried to execute. They did make the decision to go around. They did select TOGA (Takeoff/Go Around) mode. The engines did spool up to takeoff thrust. They did retract flap from 30° to 15°.

Then comes the part that is difficult to explain. They disengaged the autopilot but did not fly the airplane.

On its own the B-737, trimmed for approach, will pitch nose-up with both takeoff power and flap retraction. The accident aircraft did just that, achieving 25° nose-up, about 10° higher than the target for this maneuver. Like the DC-8 fifty years before, it was accelerating, at least until it passed the 15° target attitude.

Instrument pilots know that acceleration can produce the sensation of pitching nose-up. That might explain the Ste. Thérèse accident. It surely played an important part at Kazan.

It would have helped if the Russian pilots had been trained to expect the missed approach. Pilots call it being spring-loaded for the Go-Around. It would have helped if they knew of and expected the illusions they were about to experience from the acceleration. But most important by far are the basics, and the foundation of any emergency, indeed of any maneuver, is fly the airplane. Somehow they omitted this crucial step.

How Did We Get Here?

It would be convenient if we could put the finger on one factor, one guilty party. But there are many: deregulation; lazy captains; automation; feeder airlines, merger, and bankruptcy as tools to reduce costs; regulatory impotence. Mark H. Goodrich explores all of these in depth on his website. His unique experience (engineer, pilot, teacher, lawyer, more airplane type ratings than anyone) give him an invaluable perspective. I will summarize from my own experience.

Lazy Captains

In my younger days there were captains who grumbled it was not their duty to teach flying. Their interpretation of the adage Learn, Earn, and Return stopped with the money.

Automation

I confess I am a technophile. I love new tools. Flying my Bonanza with its Aspen Primary Flight Display fed by the Garmin GTN650 is a delight. But there are changes. My instrument scan still covers the basic 'T', but there are new items in it, and the order is different. From the airplane symbol (attitude) my eye moves an inch to the right to see if there is any pink fuzz on the altitude tape (trend) and an inch and a half down to the aqua diamond (aircraft track). If there is no fuzz and the diamond is on the arrow (desired track), no further action is necessary for the moment. I can look further out, and think for a second or two about other issues.

And here, in front of the MacBook Pro, I can think about the wider implications. How I enjoyed teaching technology on the A320, and how much flying skill I lost in my nine years on the airplane. Yes, I would make sure each of us did an “everything off” visual approach at least once per cycle (trip, 2-4 day sequence of flights). But in the Airbus such an approach is a bit of a parlor trick, chiefly because there is no trim feel.

In the Bonanza I have the best of both worlds. There is no autopilot. You fly it every second you're airborne, and then some. And the tools I have at hand are better than I had on the Airbus. ForeFlight in my iPad, fed by a tiny GPS and a satellite weather receiver. New capability arrives every few months with a software change. Flying in IMC I no longer have to request permission to leave the ATC frequency, call the FSS, and copy weather with one hand while flying with the other. Instead, my right forefinger taps the iPad over the airport of interest, and the last METAR appears. Another tap brings the forecast or the winds aloft or the airport information. One more tap and the approach I have chosen is drawn over the map in scale. Using two fingers I zoom and pan as I brief for the approach. I am still flying with my left hand.

I love it all. But is it easier than the old way?

Yes and no. In the old days you started with heading and guessed at the track made good. You integrated (looked at change over time) the localizer or VOR needle to see how good your guess was. Now you just glance at the little diamond. That's a huge improvement. But you have to learn the system, to understand what is going on. The diamond is of no use whatever if you don't know what it is. And once you do you have to retrain your eye so it knows where to look. So I am solidly with Mark Goodrich when he says that automation requires more pilot training, not less.

Airline Management Strategies

Since deregulation (1978) airline management has focused on reducing costs. Robert Crandall (American Airlines) spoke out against deregulation, but once it was law he led the way, inventing one strategy after another for his airline's survival. The first of these was hub and spoke. As I young man I flew the DC-9 across Canada on many long, thin, multiple-stop routes. By the time I was captain on the same airplane (1987) hub and spoke had arrived and there were feeder airlines flying turboprops, bringing passengers from the smaller cities into the hubs where the jets flew. This not only made economic sense – it also provided the opportunity to set up a two-tier pay scale and reduce the power of the pilot unions. But there was a casualty: apprenticeship. Young pilots starting out at the feeder had no contact with the old guys (still mostly men, even then) nearing the end of their career. Instead, they flew with captains near their own age whose only concern was getting a job with the main line. Seniority and career trumped teaching and learning. The wisdom of the old farts retired with them.

Then, as Robert Crandall so accurately predicted (in the Senate hearings on Deregulation), the airlines started losing money. There was a frenzy of merger and acquisition, and then bankruptcy. Collateral damage to pilots came in training, salary, and pension.

When I joined the airline training on a new type included two hours at the controls of a real airplane, doing takeoffs and landings. Now a pilot's first landing on a new type is on a line flight with passengers. That can be interesting. I know because I spent my last eight years as a Line Indoctrination Training Captain. For more about reliance on simulators and airline training in general, see Mark Goodrich's Simulating Reality and The Training Paradox.

Regulatory Impotence

The FAA recently changed the regulations to require that First Officers on transport aircraft have 1500 hours total time and an Airline Transport Rating. This was largely a response to the Colgan Air crash at Buffalo, NY in February, 2009. There are not enough pilots with these qualifications, and airlines are beginning to cancel flights in the smaller markets such as Grand Forks, ND.

The FAA now requires some Asian airlines to fly GPS approaches instead of visual approaches if the ILS is unserviceable. Note that aircraft “land themselves” only if an ILS is available on the landing runway. Note also that GPS approaches with vertical guidance, although they allow an autopilot to fly the airplane down a glideslope, themselves require training.

So which is better? Apprenticeship, or regulations which say only masters can fly? Training pilots in the fundamentals so they have the confidence they can fly, or regulating the level of automation they must use?

Conclusion

We have come full circle. Laziness interacts with automation, cost cutting with simulator training, loss of apprenticeship with pilot confidence and competence. The emperor has no clothes. But again, why?

The answer, I'm afraid, is simple. We can't see that the emperor has no clothes because we don't want to look. Deregulation opened airline financial decisions to the market, which means you and I, the bargain-seeking traveler, push prices down to where flight operations can no longer be safely undertaken. It has taken a generation, but that is where we have arrived.

Passing the Squonk

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The Dream

In the dream only the exact name of the term was unclear. There were equations, but the equality was in question. Did that term, whatever it is called, really cancel out? Situation followed upon situation with no logical relationship. Always, though, there was the missing term. What was it called? Was it really ever there at all?

As I emerged into semi-wakefulness the question remained, more urgent than ever. What is it? Why does it disappear? I lay quietly, trying not to breathe, not to think of anything else, to remain open to wherever I had been.

Johnny Jellybean

In the 1960's I worked at a television station as a studio assistant, the station's euphemism for stagehand. A local actor/comedian/magician had pitched them a solo show called Lunchtime Little Theatre. In those days television was black and white, and low budget was live to air with no camera men or sound men. Low budget was me and a video switcher and Johnny Jellybean. Johnny and I would set up and aim the three vidicon cameras. We would go live and Johnny would act his heart out, mostly improvising I'm sure because he never had any script or notes; the switcher would dance around between cameras, and Johnny would sometimes ride one of the vidicon dollies, pushing it around the ten by twelve studio space with one foot and grinning into the lens as the switcher focused alternately on Johnny and the moving background. It was a lot of fun. Then it would be over and I would strike the set.

Johnny was the first thing that came into my head as I lay there after the dream. I thought, my God, that's fifty years ago, where did that come from? Then I began thinking about dogs.

Dogs

They greet you like no one else does. They take pleasure in the day, sticking their heads out of the car window. When the wind comes up they delight in it – they get a gale in the tail, as Grandpa used to say.

They shed. Their farts are silent but deadly. They eat grass and puke. They drink from the toilet.

It's a package. Sure, kennels advertise expensive Labradoodles, guaranteed hypo-allergenic, but really you've still got a dog. A dog is a dog, as somebody said.

The Squawk Box

By now I was awake. Dogs and Johnny Jellybean stayed with me, wandering around, trying to be relevant. And the term, too: squank? squonk? Wait – Johnny had the Squawk Box! It was like a little wooden bird house hanging from a rope, except that there was no perch or hole. Was there a grille? Sure – it was like those speakers high on the wall aboard navy ships. Now hear this!

My memory is fuzzy. What did the squawk box squawk? Was it random tapes the switcher chose? Was it stuff Johnny had prerecorded? But I do remember the progression.

At first the box would squawk perhaps twice during a show, interrupting whatever Johnny was doing. He would mime anger, grab his wooden mallet, and hit the box. The squawk would stop. That was then. But as the months (and years, I think) went on the play got more sophisticated. It became a game between Johnny and the switcher. The box would squawk again after Johnny turned away. Or Johnny would turn away and then turn back, raising his mallet, daring it to start up again. The play would go on, keeping us high-school students, home for lunch, in stitches.

But in high school I wasn't working at the TV station yet. Maybe in those days Johnny still had cameramen. That's when he rode the dollies. The cameramen pushed him around, changing focus. The vidicons had tripods, not dollies. Could the switcher even change the focus of the vidicons? Did they have zoom?

After the Dream

Still I tried to stay in the space, keeping dogs and Johnny in mind, trying to follow the scent. Even on those rare occasions where dreams stay close, that's hard. It is like flying at night, looking for traffic, when you have to scan the sky not looking at anything because if you look it will disappear into to the cone-rich fovea. Just so I stayed aware of the space without looking.

I began reliving the dream in consciousness. Scene after scene played in my head, and indeed they are still doing so today, weeks later. As in the dream each scene is seemingly unrelated but has a common term, the term we want to make disappear.

Our Human Nature

Memory of pain fades. We are natural optimists. Sometimes a little naiveté makes the day go more smoothly.

And why not? Should we be perpetually conscious of all the evil in the world? Should we feel pain all the time? Of course not. We would become cynics, insensible to the beauty around us. That's no way to live.

But neither do we, as independent thinkers, really want someone or something else to pull the wool over our eyes, and that's where it gets tricky. We are vulnerable, you see, to those who would for their own reasons present us with a pretty picture.

 

The Scenarios

There are many, limited only by the extent of human creativity and cunning.

Pension funds, desperate for the 8% returns of yore, snap up fancy financial products composed of slices of sub-par mortgages, themselves issued fraudulently. No risk! Eight percent return!

Hedge funds return 20% by trading illegally.

The football industry gives fans what they want – tough, violent conflict – and sweeps the bodies under the rug.

Airline industry management gives travelers what they want – cheap tickets – while gutting the pioneering companies and pocketing their shareholders' savings.

Too big to fail banks trade for their own accounts, seeing their mission as making money rather than as lending money to entrepreneurs.

What is the missing term?

Risk

CDO's are rated AA or AAA. Hedge funds will take your money if you have enough. You don't have to know how they make your 20% return. Football gives you spectacle. You can luxuriate in the vicious hit as the players relish their salaries and fame. Neither of you needs to watch the dementia and death that follows. Flying is safer than driving a car. Airplanes land themselves. The inherent risk of flying and crashes and death are irrelevant. You just bought a cheap ticket. And of course you own shares in MegaBank. It's nothing to you if they are not meeting their primary obligation or if the taxpayers have to bail them out. Or is it? Do you pay taxes?

The Pretty Picture, Bad News, and Drool

Dogs drool. Some breeds are olympic-caliber droolers. Chances are if you own one of these dogs you have come to terms with drool. It makes you laugh. After all, you've got the whole dog. Same with your life. You laugh, you cry. It's all there.

Near the end of the run of Lunchtime Little Theatre, the Squawk Box antics began to merge toward the manic. Increasingly, the box just would not shut up, and Johnny mimed more madness. One day the whole thing came to an end. As Johnny hit the box, it got louder. More and more voices emanated from the box as he hammered it with his mallet. He didn't stop. He beat the shit out of it. Beat it to a pulp. Beat it to splinters.

A Canadian Multi-Crew Licence?

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document.write(" serif">Canada's Flight Training Reputation

Trying to keep Canadian flight training competitive is a laudable goal. We have a well-deserved reputation for competence, earned the hard way by flying in our terrible weather around our huge unpopulated country with plenty of pressure to get there (sooner or later) because it's often the only way to get there.

Much training business has come to our shores because of this reputation. The way to keep it coming is to maintain and bolster our good reputation in these trying times.

Loss of Control Accidents

In the last decade the character of airline tragedies has changed completely. Modern aircraft are so reliable that engine and system failures are rare. Aircraft and crew are designed and trained to deal with these failures if they occur. What we are seeing instead are crew failures.

These have come to be called loss of control accidents. The well-known examples are AF447, Colgan Air at Buffalo, and now Asiana 214 at San Francisco. There are many more, including, most recently, Southwest at LaGuardia. These accidents were all caused by crew action (or inaction).

(That includes, by the way, AF447 and Colgan, in which icing played a peripheral role. Flying into known icing is something for which the crew is responsible.)

These accidents all have something in common: pilot incompetence.

I know that sounds harsh, but it must be said. It is an accurate statement. The pilots in these cases may have known their airplane fairly well. They may have memorized their company's operating manual and their Standard Operating Procedures. But in all cases they did not understand some of the basics of flying an airplane. Colgan and AF447 fell into the ground or sea with the wing stalled, not flying, because the pilots pulled back on the control column and held the back pressure despite warnings and stick shakers. The Asiana crew pulled back to stretch their glide, even though they were far gone on the back side of the drag curve, within a few knots of the stall.

What is missing in these cases is basic flying training. The causes are legion and still being debated, but the fix is simple. In order to get a license, especially a license to fly a large airplane with many paying passengers aboard, a pilot must demonstrate the ability to take off, fly, and land an airplane while keeping it within its safe envelope. He must, in other words, demonstrate competence.

Commercial Reasoning

Canada's proposed Multi-Crew Licence has this as its rationale: Canadian flight training operators providing commercial training to foreign candidates are unable to compete with foreign operators and risk losing a segment of their industry (my emphasis).

Under various names, the Multi-Crew Licence has had a role in most loss of control accidents.

On the face of it this license seems reasonable. There is always a Captain who has a real license to supervise the others with lesser licenses. But on closer inspection what we are really saying is that a pilot who cannot legally take a friend for a ride can occupy a cockpit seat while the captain is back in First Class (AF447, and the Korean Air flight shot down over the Kamchatka Peninsula). We speak of Crew Concept and Crew Resource Management, but if the only pilot who understands the basics is not on the flight deck, these concepts are moot.

Commercial pressures have brought us, step by innocent-seeming step, to where we are today. Each step seems reasonable, at least at the time. We now routinely fly two-engine airplanes on twelve hour overwater legs. Back in the 1970's that was unthinkable and illegal. In those days airplanes didn't land themselves. Now they can, under the right conditions, and some operations manuals even specify autolands as the normal procedure. Pilots who comply are soon incompetent, unable to land the airplane by hand. But in San Francisco last month the glidepath transmitters were shut down on both runway 28's. Indeed, they had been off since June 1. Manual landings were the only way at KSFO.

The Multi-Crew Licence seems like a logical next step in response to today's commercial pressures. In reality, it is the next step toward complete incompetence on all flight decks.

Public Assumptions

Airlines have done an excellent job marketing a service that whisks you to another continent at half the speed the sun moves. Even with today's oil prices, ticket prices are (in today's dollars) a fraction of what they were in the 1960's. This is the new normal. Flights are uneventful. Pilots are bus drivers. Airplanes land themselves, don't they?

An airplane crashes at San Francisco. There must have been something wrong with the engines. Or perhaps the autothrust? A nosegear collapses on landing at LaGuardia? Obviously a mechanical malfunction.

Marketing has succeeded in making aviation seem safe. But even though airplanes have changed since the 1930's, flying is still a dangerous adventure. The safe arrival of even today's incredible airplanes still depends on the good judgment of pilots.

We don't want to think about that, because pilots are people and can make mistakes. But we'll have to start thinking about it, and acknowledging it, or the crashes will continue.

Feeders, Discount Airlines, and the Elimination of Apprenticeship

Flying is an apprenticeship trade. Like any job worth doing, it takes dedication and a lifetime of learning. I have 45 years and 19,000 hours of experience and I am just beginning to understand how little I know. But I have survived so far and I am very serious about continuing to survive. Dying by your own hand at the controls of an airplane is an absolute no-no for a pilot.

I was lucky. I have had (and still have) many fine teachers. When I was a young airline pilot most captains still took their teaching responsibilities seriously. Today's young pilot is not assured of the same. Pressure on unions and pilot salaries is being applied by business methods: spawning and dividing feeders and discount airlines foremost among them. The goal is to lower costs, but the (perhaps unintentional) byproduct is the interruption of the contact between old and young pilots and the teaching and learning that allows. (I believe that lowering wages also directly reduces respect for the job and the job satisfaction of the worker, but that is an argument for another time.) The FAA's response to the Colgan Air crash was to raise the experience requirement for First Officers to 1500 hours, even though it was the captain who was flying and who stalled the airplane and even though the airline had given insufficient training to both pilots on icing and how their aircraft handles ice. I have always understood that pilots are paid to be responsible. I am bemused by today's response to accidents, where band-aids are liberally applied to wounds which obviously require surgery.

Conclusion

Introducing a Multi-Crew Licence in Canada would be just another band-aid papering over the serious issues facing aviation today. Don't do it!

Losing Competence Part V: Asiana 214 and the Loss of Control Accidents

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document.write(" serif">Automation and Hubris

Bernard Ziegler designed the Airbus to be pilot-proof. He is a good pilot, and he noticed that many pilots are less skilled than himself. In the interest of safety, he designed an airplane that could not be stalled. But it has been known for thousands of years that hubris is followed by nemesis, that Pride goeth before destruction, and an haughty spirit before a fall. (Proverbs, 16:18)

Hubris is arrogance before the gods. The goddess Nemesis alone can see the fine line between doing the best work you can and believing that your work is somehow superior. Cross the line and she is ruthless, finding your fatal flaw and using it to bring you down.

AF 447 was the fall of the hero. Pilot carelessness led the airplane into a line of thunderstorms. Supercooled water drops overwhelmed the pitot heaters, temporarily removing all three sources of airspeed information. The autopilot dropped off. The flight control computers switched from Normal to Alternate Law. The airplane can be stalled in Alternate Law.

Human or robot, there is always a fatal flaw.

How can we work with imperfection?

Don't Bow Down

Mankind, when confronted with the complicated or the divine, tends to bow down in worship. This can be hazardous in aviation.

The new automation – glass cockpit, fly by wire, IRS and GPS – together bring a change at least as momentous as going from props to jets in the 1960's. The aircraft is now such a capable pilot on her own that she almost seems real. We called the Airbus Fifi. Rather than bowing down, we found it was much better to treat her like a person. Dare to know her and maintain a relationship.

In her early days, frustrated pilots would exclaim, “What the #$%* is it doing now?” On a go-around at KLGA the map display would disappear, the airplane sailing off the edge of the world because it had passed the last waypoint in the flight plan. Or on a miss from a visual approach at KMIA the power would suddenly go to idle. Finger trouble with the Autothrust. She was trying to maintain go-around speed.

But the answers are right in front of you on the FMA. (Flight Mode Annunciator, at the top of the Primary Flight Display) We began speaking for her, calling out any change in the FMA, so we all knew what she was doing, or thought she was doing.

And yes, most of the time she was a damn good pilot. Just as we are. Exactly the same, including the occasional lapse. Which is why there is more than one pilot aboard. And which is why the human pilot should never bow down and never step aside. Know her (the automation, Fifi, the airplane) as well as you can. Always monitor her as you would a human pilot and call out anything unusual. And if she's not doing what she is supposed to, take over. For those interested in pursuing the subject, there is an excellent video, Children of Magenta, of a lecture by an American Airlines training captain. The take-away is the same: if she's not doing what you want, take over and fly by hand. You don't have time to figure out what you did wrong with the automation.

Crew Concept – and Not Just Humans

Moving from props to jets, pilots were introduced to many new concepts: mach tuck, dutch roll, deep stall, etc. Perhaps the most important were the long, shallow drag curve and the slow spool-up time of the engines.

Moving into the fly-by-wire era, we have to accept that the airplane (her automation) is part of the crew. Philosophically, it is perhaps a stretch, but in the real world of the cockpit it is a game changer and a life saver. As soon as you accept that the airplane is part of the crew – not a superior or inferior, but an equal – everything starts to make sense. She sounds the cricket as the autopilot drops off. In Alternate Law she says Stall, Stall as the panicked pilot pulls back on the sidestick.

But if you're on approach below 1000 feet (critical phase of flight) and the descent rate is 1300 feet per minute and the airspeed is below Vapp then someone isn't doing what needs to be done. (Without a glideslope the airplane will not understand that something is wrong.) The software doesn't care if the airplane crashes. She is a good pilot but she has absolutely no self-preservation instinct, no will to live. Human pilots have, or they have no place on the flight deck.

Losing Competence Part IV: Asiana 214 and the Loss of Control Accidents

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document.write(" serif">The Drag Curve

Why did I say, yesterday, that saying pull back was exactly the wrong thing to do?

 

This is a drag curve. Every airplane has one. This looks like the drag curve of a small airplane, say a C-172. The curve for the B-777 is the same, except stretched out in the speed axis, like this:

During descent a jet's engines are at idle. Descending at perhaps 320 knots, it is near the right-hand end of the curve. Because of the 250-knot speed limit below 10,000 feet, at about 12,000 feet the pilot will pull back on the control column and hold the nose a little higher, slowing the rate of descent and trading kinetic energy (speed) into potential energy (reducing the rate of descent). As he does so he is moving left on the speed axis, toward the low point of the drag curve. Notice that drag is reducing as he slows. This means the rate of descent will decrease.

As he slows further for approach, he moves toward the low point of the curve. As you can see, in a jet the curve at this point is pretty flat, so the transition from one side of the curve to the other is a subtle one, covering, let's say, from 170 knots to 220 knots. In this range the pilot can pull back, raise the nose, and slow down without much affecting the rate of descent. Subtle though it is, this low point on the curve, the minimum drag speed, is extremely important.

Why? Because as he slows further for final approach, say to 137 knots, he is on what pilots call the back side of the drag curve. (You will more often hear back side of the power curve, but it is the same thing.) Everything changes on the back side of the drag curve. Slower speed requires more power, not less. If you don't add power, pulling back increases the descent rate. Pilots know that to stretch a glide, you (counterintuitively) have to push, not pull.

In a jet Vapp (final approach speed) is quite a way up the left side of the curve. You can see that as you slow, the drag increases, causing you to slow further. The airplane is “speed unstable”, which means that a small change in speed from turbulence or control input becomes a larger change if left to itself. What the pilot has to do is “catch” the speed as he approaches Vapp by adding power. The pilots of Asiana 214 forgot this step, and continued to slide up the left side of the curve.

There is an old pilot saying: Pull back, you go up. Pull back more, you go down. Now you are closer to understanding why, but you may ask, What happens when you get to the end, where the curve stops? To answer, we have to look at the lift curve.

Instead of drag and speed, we are now graphing lift against Angle Of Attack (AOA, or alpha). (In 1G flight there is an equivalence between AOA and speed, so it's OK to think of the AOA axis as speed, except in this graph slow is on the right, with larger angles of attack.)

AOA is the angle at which the air meets the wing. What pulling back on the stick or the control column really does is increase the angle of attack. So if the pilot needs to increase lift, he pulls back, moving along the curve to the right. But the wing only “flies” in a narrow range of AOA, from 1 degree or less up to about 16 degrees. Above that the airflow starts to detach from the upper surface of the wing and the wing rapidly loses efficiency. That is called the stall. Now the wing is more like a board. It is still pushing air around, but not nearly as much air. The wing is stalled.

You can see in the graph that as you move to the right, increasing angle of attack, lift increases in a straight line and then suddenly goes over the top like a roller coaster track. Indeed, that's just what it feels like when an aircraft stalls. Now as you pull back more lift decreases, and the bottom drops out. That's what happened to Air France 447. When the autopilot kicked off the pilot panicked and pulled. For a brief period they went up. The pilot kept pulling, and for four minutes the aircraft fell, at angles of attack well above the stall, until it hit the sea.

So that's why the drag curve ends on the left-hand side. The end of the curve is the stall. Asiana 214 was almost there, and that's why the stick shaker went off. They weren't stalled yet, but they were within a whisker. They were sitting on top of the roller coaster. And when they pitched up even further in that last second before impact (you can see it clearly the YouTube Video and in this re-enactment) it did nothing to change their flight path. All it did was lower the tail and landing gear.

Now you know why.

Next: Why aren't pilots better trained and more experienced?