The A320’s fly-by-wire system severed the tactile link between pilot and plane. It inserted a digital computer between human command and machine response. When a pilot moved a stick, turned a knob, or pushed a button in the Airbus cockpit, his directive was translated, via a transducer, into an electrical signal that zipped down a wire to a computer, and the computer, following the step-by-step algorithms of its software programs, calculated the various mechanical adjustments required to accomplish the pilot’s wish. The computer then sent its own instructions to the digital processors that governed the workings of the plane’s moving parts. Along with the replacement of mechanical movements by digital signals came a redesign of cockpit controls. The bulky, two-handed yoke that had pulled cables and compressed hydraulic fluids was replaced in the A320 by a small “sidestick” mounted beside the pilot’s seat and gripped by one hand. Along the front console, knobs with small, numerical LED displays allowed the pilot to dial in settings for airspeed, altitude, and heading as inputs to the jet’s computers.
After the introduction of the A320, the story of airplanes and the story of computers became one. Every advance in hardware and software, in electronic sensors and controls, in display technologies reverberated through the design of commercial aircraft as manufacturers and airlines pushed the limits of automation. In today’s jet-liners, the autopilots that keep planes stable and on course are just one of many computerized systems. Autothrottles control engine power. Flight management systems gather positioning data from GPS receivers and other sensors and use the information to set or refine a flight path. Collision avoidance systems scan the skies for nearby aircraft. Electronic flight bags store digital copies of the charts and other paperwork that pilots used to carry onboard. Still other computers extend and retract the landing gear, apply the brakes, adjust the cabin pressure, and perform various other functions that had once been in the hands of the crew. To program the computers and monitor their outputs, pilots now use large, colorful flat screens that graphically display data generated by electronic flight instrument systems, along with an assortment of keyboards, keypads, scroll wheels, and other input devices. Computer automation has become “all pervasive” on today’s aircraft, says Don Harris, an aeronautics professor and ergonomics expert. The flight deck “can be thought of as one huge flying computer interface.”13
And what of the modern flyboys and flygirls who, nestled in their high-tech glass cockpits, speed through the air alongside the ghosts of Sperry and Post and Saint-Exupéry? Needless to say, the job of the commercial pilot has lost its aura of romance and adventure. The storied stick-and-rudder man, who flew by a sense of feel, now belongs more to legend than to life. On a typical passenger flight these days, the pilot holds the controls for a grand total of three minutes—a minute or two when taking off and another minute or two when landing. What the pilot spends a whole lot of time doing is checking screens and punching in data. “We’ve gone from a world where automation was a tool to help the pilot control his workload,” observes Bill Voss, president of the Flight Safety Foundation, “to a point where the automation is really the primary flight control system in the aircraft.”14 Writes aviation researcher and FAA advisor Hemant Bhana, “As automation has gained in sophistication, the role of the pilot has shifted toward becoming a monitor or supervisor of the automation.”15 The commercial pilot has become a computer operator. And that, many aviation and automation experts have come to believe, is a problem.
LAWRENCE SPERRY died in 1923 when his plane crashed into the English Channel. Wiley Post died in 1935 when his plane went down in Alaska. Antoine de Saint-Exupéry died in 1944 when his plane disappeared over the Mediterranean. Premature death was a routine occupational hazard for pilots during aviation’s early years; romance and adventure carried a high price. Passengers died with alarming frequency too. As the airline industry took shape in the 1920s, the publisher of a U.S. aviation journal called on the government to improve flight safety, noting that “a great many fatal accidents are daily occurring to people carried in airplanes by inexperienced pilots.”16
Air travel’s lethal days are, mercifully, behind us. Flying is safe now, and pretty much everyone involved in the aviation business believes that advances in automation are one of the reasons why. Together with improvements in aircraft design, airline safety routines, crew training, and air traffic control, the mechanization and computerization of flight have contributed to the sharp and steady decline in accidents and deaths over the decades. In the United States and other Western countries, fatal airliner crashes have become exceedingly rare. Of the more than seven billion people who boarded U.S. commercial flights in the ten years from 2002 through 2011, only 153 ended up dying in a wreck, a rate of two deaths for every million passengers. In the ten years from 1962 through 1971, by contrast, 1.3 billion people took flights, and 1,696 of them died, for a rate of 133 deaths per million.17
But this sunny story carries a dark footnote. The overall decline in the number of plane crashes masks the recent arrival of “a spectacularly new type of accident,” says Raja Parasuraman, a psychology professor at George Mason University and one of the world’s leading authorities on automation.18 When onboard computer systems fail to work as intended or other unexpected problems arise during a flight, pilots are forced to take manual control of the plane. Thrust abruptly into a now rare role, they too often make mistakes. The consequences, as the Continental Connection and Air France disasters show, can be catastrophic. Over the last thirty years, dozens of psychologists, engineers, and ergonomics, or “human factors,” researchers have studied what’s gained and lost when pilots share the work of flying with software. They’ve learned that a heavy reliance on computer automation can erode pilots’ expertise, dull their reflexes, and diminish their attentiveness, leading to what Jan Noyes, a human-factors expert at Britain’s University of Bristol, calls “a deskilling of the crew.”19
Concerns about the unintended side effects of flight automation aren’t new. They date back at least to the early days of glass cockpits and fly-by-wire controls. A 1989 report from NASA’s Ames Research Center noted that as computers had begun to multiply on airplanes during the preceding decade, industry and governmental researchers “developed a growing discomfort that the cockpit may be becoming too automated, and that the steady replacement of human functioning by devices could be a mixed blessing.” Despite a general enthusiasm for computerized flight, many in the airline industry worried that “pilots were becoming over-dependent on automation, that manual flying skills may be deteriorating, and that situational awareness might be suffering.”20
Studies conducted since then have linked many accidents and near misses to breakdowns of automated systems or to “automation-induced errors” on the part of flight crews.21 In 2010, the FAA released preliminary results of a major study of airline flights over the preceding ten years which showed that pilot errors had been involved in nearly two-thirds of all crashes. The research further indicated, according to FAA scientist Kathy Abbott, that automation has made such errors more likely. Pilots can be distracted by their interactions with onboard computers, Abbott said, and they can “abdicate too much responsibility to the automated systems.”22 An extensive 2013 government report on cockpit automation, compiled by an expert panel and drawing on the same FAA data, implicated automation-related problems, such as degraded situational awareness and weakened hand-flying skills, in more than half of recent accidents.23
The anecdotal evidence collected through accident reports and surveys gained empirical backing from a rigorous study conducted by Matthew Ebbatson, a young human-factors researcher at Cranfield University, a top U.K. engineering school.24 Frustrated by the lack of hard, objective data on what he termed “the loss of manual flying skills in pilots of highly automated airliners,” Ebbatson set out to fill the gap. He recruited sixty-six veteran pilots from a British airline and had each of them get into a flight simulator and perform a challenging maneuver—bringing a Boeing 737 wi
th a blown engine in for a landing during bad weather. The simulator disabled the plane’s automated systems, forcing the pilot to fly by hand. Some of the pilots did exceptionally well in the test, Ebbatson reported, but many performed poorly, barely exceeding “the limits of acceptability.” Ebbatson then compared detailed measures of each pilot’s performance in the simulator—the pressure exerted on the yoke, the stability of airspeed, the degree of variation in course—with the pilot’s historical flight record. He found a direct correlation between a pilot’s aptitude at the controls and the amount of time the pilot had spent flying without the aid of automation. The correlation was particularly strong with the amount of manual flying done during the preceding two months. The analysis indicated that “manual flying skills decay quite rapidly towards the fringes of ‘tolerable’ performance without relatively frequent practice.” Particularly “vulnerable to decay,” Ebbatson noted, was a pilot’s ability to maintain “airspeed control”—a skill crucial to recognizing, avoiding, and recovering from stalls and other dangerous situations.
It’s no mystery why automation degrades pilot performance. Like many challenging jobs, flying a plane involves a combination of psychomotor skills and cognitive skills—thoughtful action and active thinking. A pilot needs to manipulate tools and instruments with precision while swiftly and accurately making calculations, forecasts, and assessments in his head. And while he goes through these intricate mental and physical maneuvers, he needs to remain vigilant, alert to what’s going on around him and able to distinguish important signals from unimportant ones. He can’t allow himself either to lose focus or to fall victim to tunnel vision. Mastery of such a multifaceted set of skills comes only with rigorous practice. A beginning pilot tends to be clumsy at the controls, pushing and pulling the yoke with more force than necessary. He often has to pause to remember what he should do next, to walk himself methodically through the steps of a process. He has trouble shifting seamlessly between manual and cognitive tasks. When a stressful situation arises, he can easily become overwhelmed or distracted and end up overlooking a critical change in circumstances.
In time, after much rehearsal, the novice gains confidence. He becomes less halting in his work and more precise in his actions. There’s little wasted effort. As his experience continues to deepen, his brain develops so-called mental models—dedicated assemblies of neurons—that allow him to recognize patterns in his surroundings. The models enable him to interpret and react to stimuli intuitively, without getting bogged down in conscious analysis. Eventually, thought and action become seamless. Flying becomes second nature. Years before researchers began to plumb the workings of pilots’ brains, Wiley Post described the experience of expert flight in plain, precise terms. He flew, he said in 1935, “without mental effort, letting my actions be wholly controlled by my subconscious mind.”25 He wasn’t born with that ability. He developed it through hard work.
When computers enter the picture, the nature and the rigor of the work change, as does the learning the work engenders. As software assumes moment-by-moment control of the craft, the pilot is, as we’ve seen, relieved of much manual labor. This reallocation of responsibility can provide an important benefit. It can reduce the pilot’s workload and allow him to concentrate on the cognitive aspects of flight. But there’s a cost. Psychomotor skills get rusty, which can hamper the pilot on those rare but critical occasions when he’s required to take back the controls. There’s growing evidence that recent expansions in the scope of automation also put cognitive skills at risk. When more advanced computers begin to take over planning and analysis functions, such as setting and adjusting a flight plan, the pilot becomes less engaged not only physically but mentally. Because the precision and speed of pattern recognition appear to depend on regular practice, the pilot’s mind may become less agile in interpreting and reacting to fast-changing situations. He may suffer what Ebbatson calls “skill fade” in his mental as well as his motor abilities.
Pilots are not blind to automation’s toll. They’ve always been wary about ceding responsibility to machinery. Airmen in World War I, justifiably proud of their skill in maneuvering their planes during dogfights, wanted nothing to do with the fancy Sperry autopilots.26 In 1959, the original Mercury astronauts rebelled against NASA’s plan to remove manual flight controls from spacecraft.27 But aviators’ concerns are more acute now. Even as they praise the enormous gains in flight technology, and acknowledge the safety and efficiency benefits, they worry about the erosion of their talents. As part of his research, Ebbatson surveyed commercial pilots, asking them whether “they felt their manual flying ability had been influenced by the experience of operating a highly automated aircraft.” More than three-fourths reported that “their skills had deteriorated”; just a few felt their skills had improved.28 A 2012 pilot survey conducted by the European Aviation Safety Agency found similarly widespread concerns, with 95 percent of pilots saying that automation tended to erode “basic manual and cognitive flying skills.”29 Rory Kay, a long-time United Airlines captain who until recently served as the top safety official with the Air Line Pilots Association, fears the aviation industry is suffering from “automation addiction.” In a 2011 interview with the Associated Press, he put the problem in stark terms: “We’re forgetting how to fly.”30
CYNICS ARE quick to attribute such fears to self-interest. The real reason for the grumbling about automation, they contend, is that pilots are anxious about the loss of their jobs or the squeezing of their paychecks. And the cynics are right, to a degree. As the writer for Flight magazine predicted back in 1947, automation technology has whittled down the size of flight crews. Sixty years ago, an airliner’s flight deck often had seats for five skilled and well-paid professionals: a navigator, a radio operator, a flight engineer, and a pair of pilots. The radioman lost his chair during the 1950s, as communication systems became more reliable and easier to use. The navigator was pushed off the deck in the 1960s, when inertial navigation systems took over his duties. The flight engineer, whose job involved monitoring a plane’s instrument array and relaying important information to the pilots, kept his seat until the advent of the glass cockpit at the end of the 1970s. Seeking to cut costs following the deregulation of air travel in 1978, American airlines made a push to get rid of the engineer and fly with just a captain and copilot. A bitter battle with pilots’ unions ensued, as the unions mobilized to save the engineer’s job. The fight didn’t end until 1981, when a U.S. presidential commission declared that engineers were no longer necessary for the safe operation of passenger flights. Since then, the two-person flight crew has become the norm—at least for the time being. Some experts, pointing to the success of military drones, have begun suggesting that two pilots may in the end be two too many.31 “A pilotless airliner is going to come,” James Albaugh, a top Boeing executive, told an aviation conference in 2011; “it’s just a question of when.”32
The spread of automation has also been accompanied by a steady decline in the compensation of commercial pilots. While veteran jetliner captains can still pull down salaries close to $200,000, novice pilots today are paid as little as $20,000 a year, sometimes even less. The average starting salary for experienced pilots at major airlines is around $36,000, which, as a Wall Street Journal reporter notes, is “darn low for mid-career professionals.”33 Despite the modest pay, there’s still a popular sense that pilots are overcompensated. An article at the website Salary.com called commercial jet pilots the “most overpaid” professionals in today’s economy, arguing that “many of their tasks are automated” and suggesting their work has become “a bit boring.”34
But pilots’ self-interest, when it comes to matters of automation, goes deeper than employment security and pay, or even their own safety. Every technological advance alters the work they do and the role they play, and that in turn changes how they view themselves and how others see them. Their social status and even their sense of self are in play. So when pilots talk about automation, th
ey’re speaking not just technically but autobiographically. Am I the master of the machine, or its servant? Am I an actor in the world, or an observer? Am I an agent, or an object? “At heart,” MIT technology historian David Mindell writes in his book Digital Apollo, “debates about control and automation in aircraft are debates about the relative importance of human and machine.” In aviation, as in any field where people work with tools, “technical change and social change are intertwined.”35
Pilots have always defined themselves by their relationship to their craft. Wilbur Wright, in a 1900 letter to Octave Chanute, another aviation pioneer, said of the pilot’s role, “What is chiefly needed is skill rather than machinery.”36 He was not just voicing a platitude. He was referring to what, at the very dawn of human flight, had already become a crucial tension between the capability of the plane and the capability of the pilot. As the first planes were being built, designers debated how inherently stable an aircraft should be—how strong of a tendency it should have to fly straight and level in all conditions. It might seem that more stability would always be better in a flying machine, but that’s not so. There’s a trade-off between stability and maneuverability. The greater a plane’s stability, the harder it becomes for the pilot to exert control over it. As Mindell explains, “The more stable an aircraft is, the more effort will be required to move it off its point of equilibrium. Hence it will be less controllable. The opposite is also true—the more controllable, or maneuverable, an aircraft, the less stable it will be.”37 The author of a 1910 book on aeronautics reported that the question of equilibrium had become “a controversy dividing aviators into two schools.” On one side were those who argued that equilibrium should “be made automatic to a very large degree”—that it should be built into the plane. On the other side were those who held that equilibrium should be “a matter for the skill of the aviator.”38
The Glass Cage: Automation and Us Page 6
