A Canadian Multi-Crew Licence?

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!

AF 447: Let’s Talk About Why – 1

Thanks to the work of David Learmount at Flight Global, and that of the Wood's Hole Oceanographic Institution and the Bureau d’Enquêtes et d’Analyses, enough is now known about this accident to start looking for useful lessons and to analyze the data along with the BEA. Flight safety and the future of the piloting profession depend on this becoming a wide and serious conversation.

Pilots obsess about accidents for good reason. There is always so much to learn. The AF447 tragedy is an epochal example.

There is a mind-boggling number of lessons to be learned here, in a host of areas and disciplines: Pilot Training, Standard Operating Procedures, Instrument Flight, and Aircraft Design are but a few of them.

I will commit today to joining the conversation. I begin with a consideration of Angle of Attack.

Angle of Attack

Wolfgang Langewiesche (father of William) emphasized Angle of Attack in his excellent Stick and Rudder, published in 1944. Advocacy of AoA was an uphill battle then and it still is today. Instead of talking about AoA, we prefer to use airspeed and explain why certain speeds we use change with aircraft weight and G loading. Many or even most aircraft flying today have no Angle of Attack indication. The accident aircraft had two AoA sensors. The flight recorders had access to the signals from these sensors but the pilots did not, at least not when they needed it most.

Lift is produced when the air flowing over the top of a wing has a longer distance to travel than the air flowing underneath. The air “stretching out” over the top produces a lower pressure, allowing the higher pressure underneath to push the wing up. There is a caveat, however. The airflow must remain attached to the upper surface of the wing.

Imagine a cross-section of wing, with a line drawn from the middle of the rounded leading edge to the pointed trailing edge. This is the chord line. Now imagine an arrow pointing at the leading edge. This is the airflow.

If the arrow meets a (symmetrical) wing head-on there will be no lift. But let the wing meet the air at a slight angle and the airflow around the wing will no longer be symmetrical: it will meet the rounded leading edge at an angle and it will divide lower on the curve of the leading edge. The air flowing over the wing will have a longer distance to travel. Lift will be produced.

The angle at which the airflow meets the chord line is called the Angle of Attack. Up to a point, increasing the Angle of Attack will increase lift. But beyond a certain point – usually about 16° – lift will instead decrease because the airflow is beginning to separate from the upper surface of the wing. This is called the aerodynamic stall, and it always happens at the same Angle of Attack.

Angle of Attack is controlled by the elevators, the control surfaces on the trailing edge of the horizontal tail. When the pilot pulls back on the stick, the elevators lift, causing a down-force on the tail and forcing the wing to meet the air at a higher Angle of Attack. Trim tabs (small surfaces at the trailing edge of the elevators) can be moved to change the neutral position of the stick. (Another way to think of it is the trim tabs change the Angle of Attack at which there is zero stick force.)

In a modern jet transport the entire horizontal tail is usually moveable. This is because of the very wide speed range of the jet and because flaps and leading edge slats also change the “trim.” The other side of the coin is that this horizontal tail, or stabilizer, is very powerful in modern jet transports. A runaway stabilizer is a true emergency. Traditionally there has been a STAB IN MOTION aural warning, and an emergency cutout switch close to hand. Most cases where the stabilizer ran all the way up or down in flight have resulted in the loss of all on board.

In most aircraft the pilot is used to trimming as he flies. A change of speed or configuration, be it in a Beech Bonanza or a DC-9, will require a trim change. With some experience on type the pilot knows (for example on a DC-9) that extending the leading edge slats will require two beeps (of the STAB IN MOTION aural warning) of nose-up trim. He can use the thumb switches on the yoke to move the stabilizer as the slats are extending and thus remain stick-neutral during the configuration change. This is part of anticipation, or staying ahead of the aircraft.

Airbus aircraft, from the A320 onwards, are different. They are fly by wire, where computers are interposed between the pilots' sidestick inputs and the control surfaces. This arrangement allows some elegant additions to aircraft design, such as envelope protection (which among other things makes it impossible for the pilot to stall the aircraft) and, relevant to our discussion today, stick force per G and autotrim.

In Normal Law, which is where the Airbus is most (and the pilot hopes, all) of the time, configuration changes can be made hands off, even flying by hand. Of course the pilot has the tips of his fingers on the sidestick, but he can make a configuration change with no pitch input because the control system, in Normal Law, will maintain 1G flight. When he calls for FLAP 1 and the leading edge slats extend, the nose-down pitch is sensed and countered by the system, maintaining 1G flight. (1G is what you experience sitting in a chair at home or in an aircraft at cruise in smooth air). In effect, the airplane is doing the anticipation for the pilot.

Like the transition in the late 1950's from props to jets, fly-by-wire has been a major change for pilots. In general we welcome it for the many advantages it offers.

Experience has shown that to do his job, which is to ensure the safe arrival of his aircraft, the pilot must fully understand a much more complex airplane. Chesley Sullenberger reached up and started the APU (the Auxiliary Power Unit, a small turbine in the tail which can supply electrical and hydraulic power on the ground or in flight) as soon as his engines lost power. Why? Because he knew his airplane and he knew he wanted to keep it in Normal Law until touchdown.

The transition from props to jets was all about speed range, speed brakes and spoilers, high Mach number, coffin corner, Dutch Roll and super-stall, but in everyday life it was more about high drag on approach, no propwash, slow spool-up times, and operating on the back side of the power curve. This change took some adjustment on the part of pilots: the more experienced pilots had more adjustments to make. The same is true with the transition to fly-by-wire.

In a traditional airplane the pilot controls Angle of Attack with the elevator and the trim tabs or stabilizer. (More often he will be thinking of Airspeed, which is the constant-weight, 1G manifestation of AofA). He is used to feel, which is essentially the change in elevator neutral point with AofA. Should the aircraft slow on approach, the nose will get “heavy”, prompting him to pull back or trim nose-up.

That feel is totally absent in Airbus aircraft. (Boeing, in the B777, have added artificial feel to their fly-by-wire system). The Airbus pilot points and shoots, so to speak. Flying by hand he can take the bird, turning on a symbol (like a bird or an aircraft seen from behind) on his Primary Flight Display. The bird shows where his velocity vector is pointed; in other words, where is airplane will be so many seconds from now if he makes no further adjustments. On approach he can pin the bird on his flare point on the runway and either let the autothrust take care of the speed or adjust the thrust levers manually. If he does the latter, he must remember that there is no feel or feedback in the sidestick.

Obviously there are quite different assumptions operating during an approach in a Bonanza, one one hand, and an Airbus, on the other. This is not necessarily a bad thing. Take for example driving a car versus riding a motorcycle. In a car you steer with the steering wheel. In a motorcycle you counter-steer, putting pressure on the inside foot-peg and forward pressure on the inside bar, in effect trying to steer the front wheel the opposite way.

But you know you're on a motorcycle and not in a car. You have learned how to ride a motorcycle.

Consider, however, flying an Airbus if something goes wrong with a sensor or a computer and you wind up in Alternate Law or Direct Law. You are in the same vehicle but suddenly the rules have changed; the assumptions have changed. It is, in effect, no longer the same machine. This is a recipe which messes with a pilot's head.

Unfortunately, experience has shown that Direct Law, where control displacement is proportional to stick force and the airplane handles like a wet fish, is actually the more benign of the two degraded modes. There is a big message in red on the ECAM saying USE MAN PITCH TRIM. The pilot moves the THS (Trimmable Horizontal Stabilizer) by moving a wheel almost a foot in diameter. This is old-style, normal airplane flying, commanding AofA with stick force and trim. There is still no feel in the sidestick, but the procedure is familiar.

Alas, in Alternate Law there is no such familiarity. It is still point-and-shoot, sort of, but autotrim is still working. As long as there is back pressure on the stick the THS trims nose-up, and vice-versa. There is NO Stabilizer in Motion warning except the movement of the trim wheels. That would seem to be an easy thing to detect, but I can testify from personal experience that it is not. On every landing (in Normal Law) the flight control computers memorize the attitude at 50 feet Radio Altitude and at 30 feet start rolling in nose-down trim, in effect trying to mimic the feel of a normal aircraft slowing in the flare. In almost a decade of flying as Captain and Training Captain, whether as Pilot Flying or Pilot Not Flying, I cannot remember ever seeing the trim wheels move.

In two recent accidents an Airbus has hit the ocean with the THS wound to full nose up. In both cases the aircraft was in Alternate Law.

I am not an engineer. There are likely many ramifications that have not crossed my mind. But sitting here this afternoon my personal recommendation would be as follows:

Disable Autotrim in Alternate Law

AF 447: Let's Talk About Why – 1

Thanks to the work of David Learmount at Flight Global, and that of the Wood's Hole Oceanographic Institution and the Bureau d’Enquêtes et d’Analyses, enough is now known about this accident to start looking for useful lessons and to analyze the data along with the BEA. Flight safety and the future of the piloting profession depend on this becoming a wide and serious conversation.

Pilots obsess about accidents for good reason. There is always so much to learn. The AF447 tragedy is an epochal example.

There is a mind-boggling number of lessons to be learned here, in a host of areas and disciplines: Pilot Training, Standard Operating Procedures, Instrument Flight, and Aircraft Design are but a few of them.

I will commit today to joining the conversation. I begin with a consideration of Angle of Attack.

Angle of Attack

Wolfgang Langewiesche (father of William) emphasized Angle of Attack in his excellent Stick and Rudder, published in 1944. Advocacy of AoA was an uphill battle then and it still is today. Instead of talking about AoA, we prefer to use airspeed and explain why certain speeds we use change with aircraft weight and G loading. Many or even most aircraft flying today have no Angle of Attack indication. The accident aircraft had two AoA sensors. The flight recorders had access to the signals from these sensors but the pilots did not, at least not when they needed it most.

Lift is produced when the air flowing over the top of a wing has a longer distance to travel than the air flowing underneath. The air “stretching out” over the top produces a lower pressure, allowing the higher pressure underneath to push the wing up. There is a caveat, however. The airflow must remain attached to the upper surface of the wing.

Imagine a cross-section of wing, with a line drawn from the middle of the rounded leading edge to the pointed trailing edge. This is the chord line. Now imagine an arrow pointing at the leading edge. This is the airflow.

If the arrow meets a (symmetrical) wing head-on there will be no lift. But let the wing meet the air at a slight angle and the airflow around the wing will no longer be symmetrical: it will meet the rounded leading edge at an angle and it will divide lower on the curve of the leading edge. The air flowing over the wing will have a longer distance to travel. Lift will be produced.

The angle at which the airflow meets the chord line is called the Angle of Attack. Up to a point, increasing the Angle of Attack will increase lift. But beyond a certain point – usually about 16° – lift will instead decrease because the airflow is beginning to separate from the upper surface of the wing. This is called the aerodynamic stall, and it always happens at the same Angle of Attack.

Angle of Attack is controlled by the elevators, the control surfaces on the trailing edge of the horizontal tail. When the pilot pulls back on the stick, the elevators lift, causing a down-force on the tail and forcing the wing to meet the air at a higher Angle of Attack. Trim tabs (small surfaces at the trailing edge of the elevators) can be moved to change the neutral position of the stick. (Another way to think of it is the trim tabs change the Angle of Attack at which there is zero stick force.)

In a modern jet transport the entire horizontal tail is usually moveable. This is because of the very wide speed range of the jet and because flaps and leading edge slats also change the “trim.” The other side of the coin is that this horizontal tail, or stabilizer, is very powerful in modern jet transports. A runaway stabilizer is a true emergency. Traditionally there has been a STAB IN MOTION aural warning, and an emergency cutout switch close to hand. Most cases where the stabilizer ran all the way up or down in flight have resulted in the loss of all on board.

In most aircraft the pilot is used to trimming as he flies. A change of speed or configuration, be it in a Beech Bonanza or a DC-9, will require a trim change. With some experience on type the pilot knows (for example on a DC-9) that extending the leading edge slats will require two beeps (of the STAB IN MOTION aural warning) of nose-up trim. He can use the thumb switches on the yoke to move the stabilizer as the slats are extending and thus remain stick-neutral during the configuration change. This is part of anticipation, or staying ahead of the aircraft.

Airbus aircraft, from the A320 onwards, are different. They are fly by wire, where computers are interposed between the pilots' sidestick inputs and the control surfaces. This arrangement allows some elegant additions to aircraft design, such as envelope protection (which among other things makes it impossible for the pilot to stall the aircraft) and, relevant to our discussion today, stick force per G and autotrim.

In Normal Law, which is where the Airbus is most (and the pilot hopes, all) of the time, configuration changes can be made hands off, even flying by hand. Of course the pilot has the tips of his fingers on the sidestick, but he can make a configuration change with no pitch input because the control system, in Normal Law, will maintain 1G flight. When he calls for FLAP 1 and the leading edge slats extend, the nose-down pitch is sensed and countered by the system, maintaining 1G flight. (1G is what you experience sitting in a chair at home or in an aircraft at cruise in smooth air). In effect, the airplane is doing the anticipation for the pilot.

Like the transition in the late 1950's from props to jets, fly-by-wire has been a major change for pilots. In general we welcome it for the many advantages it offers.

Experience has shown that to do his job, which is to ensure the safe arrival of his aircraft, the pilot must fully understand a much more complex airplane. Chesley Sullenberger reached up and started the APU (the Auxiliary Power Unit, a small turbine in the tail which can supply electrical and hydraulic power on the ground or in flight) as soon as his engines lost power. Why? Because he knew his airplane and he knew he wanted to keep it in Normal Law until touchdown.

The transition from props to jets was all about speed range, speed brakes and spoilers, high Mach number, coffin corner, Dutch Roll and super-stall, but in everyday life it was more about high drag on approach, no propwash, slow spool-up times, and operating on the back side of the power curve. This change took some adjustment on the part of pilots: the more experienced pilots had more adjustments to make. The same is true with the transition to fly-by-wire.

In a traditional airplane the pilot controls Angle of Attack with the elevator and the trim tabs or stabilizer. (More often he will be thinking of Airspeed, which is the constant-weight, 1G manifestation of AofA). He is used to feel, which is essentially the change in elevator neutral point with AofA. Should the aircraft slow on approach, the nose will get “heavy”, prompting him to pull back or trim nose-up.

That feel is totally absent in Airbus aircraft. (Boeing, in the B777, have added artificial feel to their fly-by-wire system). The Airbus pilot points and shoots, so to speak. Flying by hand he can take the bird, turning on a symbol (like a bird or an aircraft seen from behind) on his Primary Flight Display. The bird shows where his velocity vector is pointed; in other words, where is airplane will be so many seconds from now if he makes no further adjustments. On approach he can pin the bird on his flare point on the runway and either let the autothrust take care of the speed or adjust the thrust levers manually. If he does the latter, he must remember that there is no feel or feedback in the sidestick.

Obviously there are quite different assumptions operating during an approach in a Bonanza, one one hand, and an Airbus, on the other. This is not necessarily a bad thing. Take for example driving a car versus riding a motorcycle. In a car you steer with the steering wheel. In a motorcycle you counter-steer, putting pressure on the inside foot-peg and forward pressure on the inside bar, in effect trying to steer the front wheel the opposite way.

But you know you're on a motorcycle and not in a car. You have learned how to ride a motorcycle.

Consider, however, flying an Airbus if something goes wrong with a sensor or a computer and you wind up in Alternate Law or Direct Law. You are in the same vehicle but suddenly the rules have changed; the assumptions have changed. It is, in effect, no longer the same machine. This is a recipe which messes with a pilot's head.

Unfortunately, experience has shown that Direct Law, where control displacement is proportional to stick force and the airplane handles like a wet fish, is actually the more benign of the two degraded modes. There is a big message in red on the ECAM saying USE MAN PITCH TRIM. The pilot moves the THS (Trimmable Horizontal Stabilizer) by moving a wheel almost a foot in diameter. This is old-style, normal airplane flying, commanding AofA with stick force and trim. There is still no feel in the sidestick, but the procedure is familiar.

Alas, in Alternate Law there is no such familiarity. It is still point-and-shoot, sort of, but autotrim is still working. As long as there is back pressure on the stick the THS trims nose-up, and vice-versa. There is NO Stabilizer in Motion warning except the movement of the trim wheels. That would seem to be an easy thing to detect, but I can testify from personal experience that it is not. On every landing (in Normal Law) the flight control computers memorize the attitude at 50 feet Radio Altitude and at 30 feet start rolling in nose-down trim, in effect trying to mimic the feel of a normal aircraft slowing in the flare. In almost a decade of flying as Captain and Training Captain, whether as Pilot Flying or Pilot Not Flying, I cannot remember ever seeing the trim wheels move.

In two recent accidents an Airbus has hit the ocean with the THS wound to full nose up. In both cases the aircraft was in Alternate Law.

I am not an engineer. There are likely many ramifications that have not crossed my mind. But sitting here this afternoon my personal recommendation would be as follows:

Disable Autotrim in Alternate Law

Your Roof is Gonna Leak . . .

Tradespeople

I am a pilot. I am lucky to have retired without incident from a career at an airline. Flying is still in my bones.

Mine is an apprenticeship trade. You can’t learn it in a classroom or by reading a book, although both help. You have to get your hands on an airplane.

Most trades are like mine. It takes constant study to stay current in the field. The reference books, software, and reams of data relevant to the job are huge and growing. But the essential learning, the learning that serves as backbone and basis for all the stuff in the reference books, is hands-on experience taught by a mentor and teacher. In turn you should pass this knowledge on to the next generation.

Tradespeople are no better and no worse than others. The majority of them like going to work and doing the the best job they can. There is satisfaction in building something or in accomplishing a mission. You can look back and say, I built that, or I did that.

But like rule of law or paying taxes, plying a trade with skill and devotion is a social contract. Protect me from lawbreakers, ensure others pay their fair share. Give me a living wage so I can support a family, and respect my work for what it is.

Nor are we tradespeople to be divided from business people, put in a separate category. On the contrary most small businesses are founded and powered by tradespeople, be they plumbers, machinists or software engineers with ideas. Entrepreneurship and the trades are interdependent and have been since the days of the guilds. Perhaps what we are less compatible with is management.

Hubris

I was lucky also to have spent most of a decade flying and teaching on Airbus aircraft. The design of the A320 is revolutionary, extraordinary, and even beautiful. She never failed to delight me (like mariners, I thought of my ship as a person, a female) and she remains one of the loves of my life.

But she is not perfect. Call it my fallacy of anthropomorphism if you will, but I believe that a man-made object cannot be more perfect that the sum of its creators. It can be outstanding, it can be beautiful, but it cannot be perfect. Lovely as she is, my Airbus is no exception. She has her faults.

Her qualities have been called to review by two recent events with very different outcomes: Chesley Sullenberger's heroic handling of a ditching in the Hudson River, and the crash of an A330 in the Atlantic Ocean with the loss of all on board.

All airplanes have what is called an envelope. Fly faster than Va (maneuvering speed) and turbulence or rough handling can result in damage to the airframe. Fly slower than Vs (stall) and the wing can no longer generate enough lift to hold the airplane up. Fly faster than Vd (dive speed) and all manner of bad things can happen, from Mach tuck to control flutter to loss of control. The technicalities of the flight envelope can fill a book and have, many times over. The parameters include aircraft weight, air density (altitude, temperature) and G loading. But the bottom line is that it is the pilot's responsibility to keep the airplane in the envelope, to fly it as it was designed to be flown.

Bernard Ziegler had a different idea.

He was my love's Daddy. You see him in her everywhere you look. She is beautiful, intelligent, accomplished, and refined. She is uncompromising. She is very French.

She has an envelope like any other airplane. She flies with the same aerodynamics as they do. But her Daddy added a new feature to her design: envelope protection.

With the A320 and subsequent models, the pilot cannot “push the envelope”. He can push or pull as much as he wants and she will go to the edge, but not over the cliff. She is impossible to stall.

As long as she is in NORMAL LAW.

Her fly-by-wire control system is impressive in the extreme. There have been no known failures in service. But like us she depends on sensors, eyes and ears. And of course electricity to power her hundreds of computers. Starve her, blind her, or deafen her and you are asking for trouble. Chesley Sullenberger understood her. His first act was to reach up and start the Auxiliary Power Unit. This one strategic move kept power on the aircraft busses as Jeffrey Skiles, the First Officer, went through the engine restart drills. This one strategic move kept her in Normal Law until touchdown.

AF447 was approaching the Intertropical Convergence Zone, the ITCZ, the doldrums. It was night and as usual there was a long line of thunderstorms in the Zone, crossing their track obliquely. The Captain had just left the Flight Deck for his planned rest. The most junior pilot – the relief pilot – was in the left seat flying the aircraft.

Ahead of them a small storm was showing on the radar. Despite its size it was dense enough to reflect all of the energy from their radar. The result – a well-documented phenomenon called attenuation or blanking – was that a gap appeared in the line behind the small storm. AF447 flew around the corner and suddenly the gap was gone. They were plowing into the main line of thunderstorms.

Supercooled water is unusual at FL350 but not unusual in thunderstorms. Drops of supercooled water freeze instantly when disturbed – as for example by a fast-moving aircraft. The temperature that night was an unusually warm minus 40 C., just warm enough to keep the drops from freezing and cold enough so the heating elements in the A330's pitot probes were not powerful enough to keep the probes open. All three pitots were temporarily blocked, cutting off all airspeed information.

She was blind and deaf. Panicked, she shut down her envelope protection and called out to her pilots for help, shutting down the autopilot and autothrust and reverting to Pitch Alternate Roll Direct Law. Visual and aural warnings cascaded across the ECAM and into the speakers. Beautifully designed and prioritized for foreseeable failures, the warnings that night became a powerful distraction, demanding the pilots' attention at just the moment they needed to ignore her.

She was squealing like a stuck pig. If the pilots could have read her right that night, what they would have heard was, I'm gone, guys. I'm outta here. You have control.

Blind, deaf, and still squealing, the A330 handed control to the relief pilot. He pulled back on the sidestick. She zoomed upwards, climbing to FL380 at 7000 feet per minute, rapidly losing energy, her angle of attack increasing toward the stall. In Pitch Alternate Roll Direct Law the pilot's back pressure on the sidestick was also moving the powerful Trimmable Horizontal Stabilizer, moving it slowly to full nose-up, effectively locking them into the stall that would follow momentarily.

Today David Learmount of Flight Global posted a blog titled Being an airline pilot isA profession in decline”. Is it really? He quotes from William Langewiesche's book Fly by Wire, citing Langewiesche's admiration for Bernard Ziegler and the Airbus and his ambivalent attitude toward airline pilots. I will add another quote from the book:

“What did Ziegler want? He wanted to build an airplane that could not be stalled – not once, not ever – by any pilot at the controls.”

She fell flat, nose and wings level with the horizon, falling not flying, her angle of attack near ninety degrees, her rate of descent 10,000 feet per minute. Four minutes later she hit the water.

Nemesis and Lesson

Here is another quote from Fly by Wire:

“If you design airplanes for (airline pilots) to fly, you must grapple with not only with the existence of a few who are incompetent from the start, but also with the fact that plenty of once-excellent pilots grow unsafe with time. They become arrogant, bored, or complacent. They drink, they fade, they erode.”

Bernard Ziegler is (was) a brilliant test pilot and engineer. (Like me, he is getting older.) He knew that he was on the far right flare of the bell curve. He knew (as do we all) some examples from the left rim of the bell.

I am from somewhere in the middle of the curve. I was lucky, worked hard to maintain my competence, and survived my job. I don't dispute the factuality of the above quote. But I would add a caution:

Underestimate a tradesperson at your own risk.

Chesley Sullenberger knew his airplane, respected her and treated her like an equal. He expected Jeffrey Skiles to act professionally and he did. He was proud of his profession, his trade. That was his true achievement. The successful ditching followed from it, a corollary.

David P. Davies gets it right-way-around in his classic Handling the Big Jets:

“Airline flying is just money for old rope most of the time . . .”

He recognizes, as pilots say, that flying is hours of boredom punctuated by moments of sheer terror.

But he also points out the need for training of the highest quality. That designing an airplane that is capable of landing safely with half its engines failed is of no use if you haven't trained the pilots to do the maneuver. If you haven't given them the confidence that they can.

So pilots: know your airplane. Treat her and your fellow-pilots well. Expect the best from them.

And to everyone, especially homeowners: respect tradespeople. Search out those who are proud of their work. Especially if you're looking for a roofer.