17 min read
When Flight Computers Crash

by William Thomas

Okay, so you’re almost bored swanning through Earth’s upper atmosphere at a high fraction of Mach. Except for the part of you that keeps protesting, “This is not natural.”     

     The main thing about flying a plane is not to stall more than a few inches above the runway. An airplane stalls when the wings are inclined so steeply, they lose lift and can no longer keep it airborne. This hasn’t changed since the Wright Brothers. When I was 16, I used to practice stalls in a rented Cessna by chopping power and pulling the nose up. With the stall warning horn blaring and the little two-seater suddenly tilting sharply towards the ground, I pushed the throttle forward and held the nose hard down, leveling off when flying speed was regained.     

     Falling out of the sky is no biggie when there’s altitude to spare. Presumably, the pilots up in the pointy end desire to live as much as you do. They’re doing an excellent job so far – turns are smooth and gentle, each thrust application uncannily precise. Here’s the captain now…     “Howdy, folks. Roger Ramjet here. I’m the guy in front supposedly driving this thing. It is true that only my superhuman flying skills stand between you and fiery death. But fear not. I got this.”

In fact, both pilots are on a working holiday. Flirting with the flight attendants, yarning about their weekends, twisting a knob, updating the airplane's logbook, turning a dial, reporting in, gazing at the cloud deck far below. The airplane has the airplane. 

     Yes, that’s right. This thin-skinned conveyance hurtling through even thinner air near the hairy edge of its performance envelope is flying itself. Specially trained hominids still guide 350-ton airliners through the takeoff roll, before turning over control to the autopilot around 50 to 100 feet. And they usually hand-fly the last 200-feet of their final approach, after the aircraft has configured itself to land. But that’s about it. 

     The remarkable news is that huge commercial jetliners are nearly sentient, with multiple redundant computers keeping the airplane within safe limits, while micro-responding to electronic navigation aids and control-surface feedbacks without human intervention. Airlines insist that algorithms do the aviating, because robots fly more smoothly and exactly than mere humans, saving expensive fuel, and wear-and-tear on engines and airframes. The troubling news is that button-pushing airline pilots are losing basic flying skills that will be urgently needed when aircraft systems fail and befuddled flight-computers suffer paralysis. 

     Or worse.


After leasing one of their Airbus A320s to a German airline, Air New Zealand pilots and representatives are conducting a flight test prior to accepting the handback. The final exercise will drastically slow the jet to check its automatic stall protection, which should respond by nosing the airplane down, powering up both turbines and accelerating to full flying speed. Instead of carrying out the stall test at the recommended 14,000 feet, the crew decides to conduct it at 4,000 feet on their return to the airport. No minimum airspeed to commence manual recovery is established. And no one onboard imagines that rinsing off the plane for delivery has introduced water into two angle-of-attack sensors needed to prevent an incipient stall. At higher altitudes during their test flight, those trapped water droplets have frozen. 

     The Pilot Flying retards the throttles and nudges back on his side-stick to tilt the nose up. Like a video game at home, there is no feedback, no “feel”, no sensation of control surface response. You just move it to make the digital displays read what you want. As their flying speed degrades, everyone in the cockpit is waiting… waiting… waiting for the automated stall protections to trigger.



Flight JT610 takes off at 0620 local time from Jakarta, bound for the Indonesian island of Bangka with 169 humans onboard. Three minutes and 22 miles after takeoff, the pilots request and receive clearance to return to the airport. They do not declare an emergency. But climbing through 4,000 feet, their recalcitrant Boeing 737 “Max 8” jet wants to dive toward the sea. Every time the captain pulls the nose up, an automatic anti-stall system called MCAS (m-cass) pushes it back down.   

     Because two bigger engines mounted further forward on the wings can destabilize their new jet, Boeing has inserted additional lines of code into Max 8 flight computers. The Maneuvering Characteristics Augmentation System pushes the nose down if it senses the plane nearing a stall. On older 737’s, the autopilot can be disconnected by pulling on the yoke. But not the MCAS. The pilots in charge of flight JT610 have never heard of MCAS. “They have no idea Boeing has introduced something new,” a 737 captain and former fighter pilot for the Swedish air force will later comment. 

     “Airplanes are like computer games nowadays,” observes aviation analyst, Colleen Keller, reiterating a dangerous misperception. Computer games do not soar above unyielding countryside and densely populated cities at 530 knots. While making flying much safer, highly automated glass cockpits have turned pilots into knob-clickers, while their basic flying skills erode. When computers are confused by faulty inputs, the resulting cascade of error messages scrolling down the central flat-panel display – each sounding its own continuous alarm – can swamp human brains. 

     “Crews sometimes struggle to deal with the complexities of the automated systems,” admits James Healy-Pratt, Head of Aviation at Stewarts Law. They are not trained to cope with improbable computer glitches “by manually flying the aircraft.”   

     “There is simply no arguing with the success of the automation,” argues William Langewiesche. Thanks to fourth generation automated airliners, “plummeting” fatal accident rates have prompted some air crash investigators at the National Transportation Safety Board to retire early. “Automation has made it more and more unlikely that ordinary airline pilots will ever have to face a raw crisis in flight,” the veteran pilot, author and aviation expert continues, “but also more and more unlikely that they will be able to cope with such a crisis if one arises.” 

     “When trouble suddenly springs up and the computer decides that it can no longer cope,” chimes in Jeff Wise, a contributing editor for Popular Mechanics and author of Extreme Fear: The Science of Your Mind in Danger, “the humans might find themselves with a very incomplete notion of what's going on.” What is the primary threat? Which instruments are still reliable? Which can no longer be trusted? “Unfortunately,” Wise whispers, “the vast majority of pilots will have little experience in finding the answers.” 


An engineer named Earl Wiener famously penned four laws of aircraft automation: 1. Every device creates its own opportunity for human error. 2. Exotic devices create exotic problems. 3. Digital devices tune out small errors while creating opportunities for large errors. 4. Some problems have no solution.   


Industrial engineer Nadine Sarter has written extensively about the “automation surprises” that occur when pilots are unaware their rebellious airplane has switched into cranky-autonomous mode.                                      

     In olden times, when this navy reservist entered the cockpit of a rattletrap Flying Boxcar somewhere over the Nevada desert to find the navigation radio tuned to a jazz station, I knew enough to loudly inquire, “Are we lost?” “Of course,” answered the marine in the left seat, uttering the required response without looking up from the Playboy centerfold he was admiring. These days, according to Langewiesche, the expected cockpit question is: ‘What’s it doing now’?” 

     Sarter went on to observe that the many complex subcomponents in modern aircraft can interact in unexpected ways that pilots cannot immediately recognize. In conversation with five engineers, Sarter learned that even the men who built the plane could not agree how it worked. 

     As for the pilots… “Well, Good luck.” Airline pilots think they understand their clever machine, only to find the airplane defying their control inputs. Happily, the ensuing steep learning curve rarely leads to accidents. But as Boeing’s Delmar Fadden explains, “Once you put pilots on automation, their manual abilities degrade and their flight-path awareness is dulled: flying becomes a monitoring task, an abstraction on a screen, a mind-numbing wait for the next hotel.” 


Nadine Sarter calls this pernicious process, “de-skilling”.  As Langewiesche relates, Captain Dubois had logged 346 flight hours over the previous six months. But he’d manually flown “for at most only about four hours” during the past year. Bonin had about the same amount of “stick time”; Robert less. 

     “For all three of them, most of their experience had consisted of sitting in a cockpit seat and watching the machine work.” Even worse, advanced flight computers are “covering” for mediocre pilots. “As a result, the mental makeup of airline pilots has changed,” Langewiesch remarks. “On this there is nearly universal agreement – at Boeing and Airbus, and among accident investigators, regulators, flight-operations managers, instructors, and academics. A different crowd is flying now, and… the knowledge base has become very thin." 

     Which means… “We are locked into a spiral in which poor human performance begets automation, which worsens human performance, which begets increasing automation.”  

NIGHT, JUNE 1, 2009 2229 GMT (7:29 PM local)

Air France Flight 447 departs Rio de Janeiro for Paris. As the Airbus A330 “heavy” heads out over the Atlantic, 216 passengers and 12 crew are looking forward to the City of Lights they will never reach. (The following timeline indicates total elapsed hours, minutes, seconds since takeoff.)

0148: Flying beyond ground radar coverage, co-pilot Pierre-Cédric Bonin picks up the first storm on the plane’s weather radar, some 200 miles ahead. Captain Marc Dubois is not impressed. He is reading a magazine and wants to talk about tax havens.    

0151: The captain expresses concern that if they don’t climb about flight level three-six (36,000 feet), “we might be in trouble” with the weather. He adds, “It’s going to be turbulent when I go for my rest." Bonin observes that reaching three-seven is “going to be a bit tight.” He’s already mentioned that they would have to wait for nearly an hour to burn off enough fuel to climb higher. Roberts (ro-bare) returns from his rest. Did he sleep? Not really, he tells Dubois (doo-bwa).

0156: They are closing fast on the notoriously rough equatorial weather. So another 15-minutes flying should see them elbow their way through the storm cell bullies that typically crowd the ocean-spanning Intertropical Convergence Zone. “Should” is not a flying term. Bonin keeps asking when they are going to climb above the storm. But Captain Dubois demurs. With their present load of fuel and passengers, if they climb much higher they will be flying into the “coffin corner” where high-speed and low-speed stalling speeds edge together. Dubois elects to take his scheduled break, leaving the “airline baby” – Bonin, with 3,000 flying hours – to “monitor” the robot plane. 

     “I didn't sleep enough last night. One hour, it's not enough,” Captain Dubois protests. He has spent the previous night and following “rest day” in Rio with his girlfriend, currently seated in the passenger cabin aft.

0200:08 “Well then, I’m out of here.” The captain has decided that the storm they’re about to enter is not so bad after all. Like any weary executive, he disappears into the tiny flight-rest compartment behind the cockpit. Airbus initially wanted to call the pilots of its new automatic airliners, “flight managers”. It’s an accurate description. And a dangerous assumption adopted by too many “managers” who let the flight management computers do all the work. 

     Everything’s fine. The airplane is contentedly flying itself, making .82 Mach way out in the middle of nowhere at 35,000 feet. The radios pop and crackle. Robert returns from his nap. He changes radar settings and sees that they are heading straight into intensive thunderstorm activity.        

     Bonin dials back the speed, selecting .80 Mach. “Putain la vache. Putain!” he curses the outside air temperature. Though well below freezing, it's warmer than expected, preventing them from climbing to a higher altitude. The temperatures and moisture they’re flying through are also ideal for icing up the pitot tubes. Located under the nose, those three redundant air-pressure probes are feeding altitude and airspeed data to the airplane’s identical flight computers. The pitots' propensity to icing up on A330’s is well-known. Such incidents over the last year have sharply increased in frequency. Instead of grounding the fleet until a fix can be arranged, Air France has moved to replace the problem probes with an improved design as they become available. The first shipment has just arrived in Paris, awaiting installation when Flight 447 arrives.

0210:04: Ice crystals can be heard hissing against the windscreen. Robert is looking at a massive thunderstorm painted by the radar as an angry red blob dead ahead. He says, “You want to go a little to the left?” (Hint-hint.) “Excusez-moi?” Bonin is startled by the notion. The ever-diffident Robert suggests his colleague might “eventually go a bit to the left.” Instead of continuing head-on into extremely violent turbulence, precipitation and wind shear. Why not? Bonin clicks the autopilot knob 20 degrees left. The blob moves aside as the big jet turns onto the new heading.

0210:05: Over the next minute, the Airbus automatically issues 14 system failure messages to Air France operations showing inconsistencies between all three airspeed indicators. As a result of ice buildup inside the pitot tubes, the speed readouts are telling conflicting and improbable tales. As William Langewiesche relates, neither pilot has time to notice these anomalies before the autothrottles and autopilot respond to the loss of credible airspeed data by dropping offline. A soft C-chord chime warns that the flight computers have given up trying to fly without reliable inputs and someone else ought to consider hand-flying the airplane. It is not an emergency. The Airbus continues flying normally through light to moderate turbulence. All is snug inside the blue LED-washed cockpit. Everything outside is black...

Back onboard the Air New Zealand jet, deceived by the frozen angle of attack (AoA) indicators, the flight computer is blithely ignoring the approaching stall. “Don’t sink! Don’t sink!” the airplane shouts. The slowing A320 yaws left and right, swinging the nose from side-to-side. The pilot-in-command powers up and pushes the side-stick forward. The nose tilts down. Then it starts back up. 

     What is happening? The pilots don’t realize that the automatic horizontal stabilizer on the tail is trying to “save” the falling airplane by pitching full up. This is the worst possible response. The jet tilts up at an impossible angle, then fully stalls, mushing bottom-first towards the Mediterranian Sea. There is not enough altitude to recover. No one survives the crash off Perpignan, France.   AoA #1 sensor from wreckage -BEA                                              

0210:03: Both First Officers are startled when the autopilot-disengaged alert sounds a cavalry charge. Neither junior pilot has been trained to deal with wonky airspeed indications at high cruise altitudes while hand-flying the airplane. Reaching for his side-controller, Pierre-Cédric Bonin announces that he has control. He doesn’t. The digital tape in front of him shows them flying at 274 knots. 

     Bonin is rattled. The plane’s least-experienced pilot believes they are about to overspeed, though that’s impossible at cruise in level flight. Besides, the throttles and flight control settings have not changed. “Trust your instruments” is ingrained in pilots from our very first flight. And in automated jets, the corollary is: “and periodically cross-check yours with the duplicate set in front of the other pilot.” 

     Instead, Bonin hauls back on his Gameboy-style controller. Has he forgotten how to fly? As Flying’s Peter Garrison explains, in more than a dozen previous “unreliable airspeed” Airbus adventures, more than one startled pilot jerked back on the controls – the very opposite of what they must do. Which is nothing at all. Not until their heart rates slow and they get things sorted. Bonin’s abrupt pull-up pulls their speed back to a reported 52 knots. A Cessna will not fly, let alone climb, at this airspeed. Yet both “steam gauge” altimeters and Vertical Speed Indicators are showing a climb. Their speed must be 152 knots. Or maybe it isn’t. Total confusion descends on the cockpit of flight 447.

0210:05: Turbulence is light. Still sucking on those blocked pitot tubes, the automated Primary Flight Display shows the airplane has lost 1,000 feet of altitude and is descending at 600 feet per minute. The crossbars on the Flight Director, which recommends the best pitch angle for any situation, keeps flicking on and off. Each time it reappears, it commands a 12-degree climb.       

0210:07: Rocketing upwards at nearly 7,000 feet-per-minute, the steeply-tilted wings are causing turbulence over their leading edge, bleeding lift. Bonin crushes the side-grip, rocking the heavy aircraft left and right. Not a wise procedure in the thin air at 35,000 feet. But he’s trying to get the feel of a very different airplane, made extra-sensitive by the degraded flight computer reverting to manual mode. 0210:10 Six seconds after Flight Officer Bonin claimed control, the “stall-proof” airplane addresses both pilots in a loud, firm male voice no on-duty airline pilot ever wants to hear: “STALL.”

0210:31: “Go back down. This says you’re going up. According to all three [basic flying instruments] you’re climbing. Go down again,” Robert tells Bonin. “Okay,” Bonin acknowledges. “We’re in… yeah, we’re in climb."

0210:34: Robert's left-side instruments suddenly show a jump in airspeed to 215 knots. Can this be true?

0210:40: Robert presses a button to call the captain.

0210:49: “Dammit, where is he?” Robert exclaims.

0210:55: “DAMMIT!” he repeats. No captain appears.

0211:00: “Above all, try to touch the lateral controls as little as possible, eh.” Robert is worried about entering a spin at this altitude and climb angle. He is trying to teach Bonin how to fly.

0211:04: Standby instruments appear to confirm their airspeed. The wing's angle of attack is edging toward an unsustainable 30-degrees. But the pilots no longer trust any of their instruments. First Officer Bonin in the right seat keeps pulling back hard. Nearly continuous C-chords are sounding like a dozen cars with their doors left open. Because their side-sticks are not interconnected, Robert cannot see or feel Bonin pulling back slightly on the controls. At least three separate and duplicated instruments confirm the continuing climb. They have been flying for just over two hours. 

     “What was that?” Robert blurts. 

     The airplane replies, “STALL STALL.” 

     “We don’t have a good indication of… speed!” Bonin bitches. 

     “We’ve lost the speeds!” Robert replies from the left seat, sharing his companion’s fixation.

Ignore unreliable airspeeds! As my instructor made me practice one memorable afternoon, loss of indicated airspeed in flight is disconcerting. But it is not needed to remain aloft. If the Air France pilots leave the power settings at 83-precent thrust and park the nose 5 degrees above the white horizon-line of their backup Attitude Indicators, the twitchy jet will return to its preferred cruise profile.      

     Unlike the computer-driven Primary Flight Display duplicated in modern “glass cockpits”, where LCD screens showing digital readouts replace Lindbergh-era analogue gauges, the gyro-stabilized Attitude Indicator is not driven by inputs from pitots and computers. 

     They have not trained for this. Bonin switches off the thrust locks, causing both engines to spool up to fully urgent power. Back in the cabin, dozing passengers awaken or modify their dreams. 


“Alternate Law. Protections Lost,” Roberts chants. The plane’s automation has thrown up its hands and is no longer guarding them from a high-altitude stall. Anything could upset them. Twenty seconds have passed since the airspeed indicators quit. There they are, Langewiesche writes, “soaring upward through increasingly thin air at 36,000 feet, bleeding off speed, the nose a dangerous 12 degrees up.” Another jet following some distance behind them has veered sharply west, away from the storm center, after reporting “particularly severe turbulence...” at 36,000 feet. 

  “Dammit, is he coming or not?” says Robert.

  0211:10: “Do you understand what’s happening or not?” Robert asks the man flying the heavy jet. 

     “I don’t have control of the airplane any more now,” Bonin responds. They are just along for the remaining three-and-a-half minute ride.

0211:22: Passing through 38,000 feet, the severly abused Airbus reaches the top of its zoom climb. Stalling completely, it begins to drop 11,000 feet every minute towards the indifferent sea. As forward speed drastically decays, the intermittent stall warnings cease. Teetering in that thin air, they are lucky the big jet doesn’t drop a wing and fall off into a spin. As the aircraft descends, the pitots thaw in the warmer air. Hurrah! Their airspeed of 183 knots is now being correctly shown on their Primary Flight Displays. So is their acute pitch-up angle. But neither pilot is buying what they believe to be lies and misinformation.

0211:43 Captain Dubois bursts into the cockpit. “What the fuck are you doing?” he demands. (The public transcript reads: “Er, what are you doing?” – an incongruously mild inquiry from a parent who has left both kids playing, only to return to find them burning down the house.) Both relief pilots recoil like scolded siblings. Now would be a good time for one of them to mention that their sleek conveyance is fully stalled, nose-up and plunging like a brick dropped from seven miles up. But they never believed all those insistent stall warnings, chimes and “crickets”. 

     So they don’t. 

     “What’s happening? I don’t know. I don’t know what’s happening,” Robert admits. 

     “We’re losing control of the aeroplane here,” says the Pilot Flying. “We lost all control of the aeroplane. We don't understand anything. We’ve tried everything,” Robert adds. Another 45 seconds pass as three anxious pilots attempt to make sense of the nonsensical. As the Airbus belly-flops straight down, Bonin continues holding the nose way up – beyond 16 degrees. 

     "What is the airplane doing?" is a disorienting puzzle they’d better solve quick. The computerized Primary Flight Display may have gone insane. But their old-fashioned “steam gauge” Attitude Indicators show them wings nearly level. And unsustainably high above the horizon. Gyroscopes don’t lie. Unless they tumble during violent flip-flops. And then a red OFF flag would appear. But no one remarks on inoperative gyros. Or their unusual nose-high attitude. Or the fact that they are falling out of the sky. Extreme stress is freezing their brains as thoroughly as the pitot tubes outside. 

     But they have a powerful artificial brain to troubleshoot the problem. Scrolling text on the aircraft monitoring computer mounted on the pedestal between the pilots “should” be alerting them to the frozen pitot tubes and recommending the proper course of action. It isn’t.

0211:58: “I have a problem. It’s that I don’t have vertical speed indication,” Bonin tells the captain. “I have no more displays.” 

     “We have no more valid displays.” Robert agrees that their expensive computers are junk. 

     “Alright,” the captain acknowledges. He does not mean it’s okay. Without a trustworthy VSI, they cannot know whether they’re climbing or diving. The yellow Master Caution light is winking on and off as the airplane continues to intone: “Stall stall stall stall stall.” 

     It will call out this warning 75 times before being violently shutoff. But none of the pilots will ever mention it. Brainlock is hard to dispel when multiple scary stimuli persist. Dubois and Robert are still unaware that Bonin is frozen like someone caught on a cliff face. Robert has twice warned his co-worker they were climbing. :Climb!” Bonin had replied – whether by way of acknowledgement or intention is not clear. The junior co-pilot continues to force his controller hard back, keeping the airliner fully stalled.

0212:04: Bonin says he still believes they have “some crazy speed.” He asks what everybody else thinks. He is trying to work a problem none of them has ever encountered. Not even in the simulator. Why train for the impossible?

0212:11: “So we’re still going down,” Bonin correctly ascertains.

0212:13: “What do you think we need to do?” Robert asks Dubois. “I don’t know,” the captain replies, adding, “There, it’s going down.” Does he mean their high nose-up attitude is coming back down? 

0212:21: “That’s good. We should be wings level,” Bonin says. “No, it won’t…”     They continue to fly nose-high, losing more than 10,000 feet every minute.

0212:23: “The wings to flat horizon. The standby horizon.” Reduced to the role of flight instructor, the captain is teaching Bonin how to fly by using his back-up instruments. The mechanical artificial horizon is apparently still working! First Officer Robert must have given up on his flight-mate's piloting ability, because the airplane announces, “dual input” – complaining that both co-pilots are making contradictory control inputs.

0212:27: “You’re going down, down, down,” Robert tells Bonin. 

                “Going down,” echoes the captain. It could be their epitaph.

0212:30: “Am I going down now?” Bonin asks. This is not what Capt. Marc Dubois wants to hear. What does he know? One-minute ago he was lying down with his eyes shut. Now, he is only certain that trying to exchange seats with either subordinate is too risky. Robert pushes his side-stick sharply forward, trying to dive the airplane. He cannot feel Bonin pulling back. And Bonnin can't feel him. Seated side-by-side, both pilots arm-wrestle for nearly another minute, neither one feeling the other's resistance. Their confusion must be complete. Rolling slightly left, they have turned through 180-degrees and are heading back south. How the passengers are reacting is not known. But the soundest sleepers are in for a shock when they wake up dead. 

0212:30: “Am I going down now?” Bonin asks. “Go down,” says Robert. He means, get the damn nose down!

0212:32: “No, you climb there. You’re climbing,” the captain interjects. “I’m climbing, okay, so we’re going down,” says Bonin, now lost in Wonderland.

0212:41: “What are we here? On alti(meter), what do we have here?” Bonin asks. “C’est impossible,” exclaims his captain.
Airbus A330 automated cockpit -Sean McCabe

0212:52: “Hey you. You’re in…” Was Captain Dubois about to say, “a stall’? “That’s what I’m trying to do,” Bonin comes back. But no airplane can be unstalled by trying to force it to climb.

0212:57: “Get the wings horizontal," orders the captain. “I’m at the limit… with the roll,” Bonin complains. Unlikely. Without overcontrol protection from the off-line computers, they would be in a steep wingover if he was. “Dual input,” says the airplane as Robert fights back.

0213:00: “The rudder bar,” calls out the instructor-captain, reminding Bonin to pick up the dropped wing with opposite rudder – not the ailerons out on the wings. “Wings horizontal… go… gently gently,” Dubois coaches.

0213:11: “We lost it all…” Robert despairs. He means the glass flight displays. The gear-and-lever backup instruments are apparently hanging in there. “Hey, er…” says Captain Dubois. “I’ve got nothing here,” Robert repeats. “What do you have?” asks the captain four seconds later.

0213:32: “It won’t do anything,” Dubois appends. The deeply-stalled airplane is not responding to simultaneous hard back and full forward control inputs.

0213:37: “9,000 feet!” Bonin shouts.

0213:39: “Climb, climb, climb,” Robert urges the airplane. “But I’ve been at maxi nose-up for a while,” Bonin finally admits. That must have blown some minds. “No, no, no. Don’t climb!” orders Captain Dubois. Stop pulling the nose up! "Stall stall stall stall" comes the dirge that has been sounding throughout their ordeal. “Dual input, dual input,” the Airbus continues to protest.

0213:45: “So give me the controls. The controls to me, controls to me,” Robert belatedly demands. “Go ahead. You have the controls. We are still in TOGA, eh,” says Bonin, reminding Robert that the engines are still in full-power Takeoff-Go Around mode. It’s the standard incipient-stall recovery procedure for an Airbus at low altitude. But Bonin does not relinquish his side-stick. “Dual input” comes the notification again.

0213:53: In lieu of anything better to do, Captain Dubois turns off the automatically disengaged autopilot. Click goes the selector. “AP off,” he says.

0214:00: “Gentlemen,” says Bonin. He does not add, It’s been an honour and a privilege serving with you. 

0214:05: The alarms are still sounding. “Watch out, you’re pitching up there,” warns the captain. “I’m pitching up,” Robert acknowledges, as if responding to a command. “Well we need to. We are four-thousand feet,” Bonin throws in. They are dead men falling.

0214:18: “Go on, pull,” says the captain. “Let’s go! Pull up! Pull up! Pull up!” Bonin concurs. The airplane joins the chorus, insisting in a deep male voice, “PULL UP!”

0214:24: “We’re going to crash,” Robert says loudly. “This can’t be true. But what’s happening...” “Ten degrees pitch attitude,” Dubois says. Then someone – Bonin? – apparently shouts, “Putain! Fuck. We're dead!” (Omitted from posted transcript.) If this really is the junior pilot’s final assessment... he is correct. 

0214:28: Sound of impact.   AF447 fuel slick spotted by Brazilian Air Force patrol plane -Reuters


Presumably, the Lion Air briefing room that morning would have been abuzz with the news that the previous evening a faulty angle-of-attack readout on an arriving A320 had caused the primary flight computer to shove the nose into repeated 20-degree dives. “We felt like in a roller coaster,” passenger Alon Soetanto recalled after landing in Jakarta. “Some passengers began to panic and vomit.” 

     Then again, maybe not. It’s the third such incident for this airplane – the same one they are taking off now. If they had checked the aircraft maintenance log before start-up, as required by flight regulations, JT610’s paired human guides would have been reassured to see that one of the plane’s two angle-of-attack sensors had been replaced on its arrival from Bali the previous night. What they do not know is that despite being certified “serviceable” by the FAA, the refurbished device has been sending spurious “climb” readings to their flight computers ever since they broke ground. Since they want to climb, the pilots are in agreement with their machine. 

     But when they momentarily level off, the faulty sensor tells the computer they’re ascending at a dangerously steep angle. They are also unaware that the day before, on the earlier flight from Bali to Jakarta, an off-duty pilot “dead-heading” home in the cockpit jumpseat correctly diagnosed the problem. He advised the struggling crew to cut power to both powerful engines, which were trying to drive the nose up – triggering the MCAS. His life-saving presence was not contained in the Indonesia’s National Transportation Safety Committee’s November 28 report. 

     But Captain Bhavye Suneja does not share their luxury of a higher altitude and an extra pilot who knows how to defeat the killer MCAS. Instinctively, Behave pulls back on the the Boeing’s black control column. The airliner comes back level. But five-seconds later, it tips sharply downwards again. Overpowering its human pilot, the computer holds the nose firmly down for 10 long seconds. Try counting from 'one-one-thousand' up to ’ten-one-thousand' while diving toward the drink from 4,000 feet. 

     Capt. Suneja does not wait. He goes to Plan B: blipping the electric stabilizer trim on his contrlol yoke. When the airplane obediantly pitches back up, away from the water, he emancipates the switch. Undesired nose down movement “can be stopped and reversed with the use of the electric stabilizer trim switches,” Boeing will helpfully confirm in a subsequent emergency Airworthiness Directive. 

     But – and it’s a killer ‘but’ – the dive “may restart 5 seconds after the electric stabilizer trim switches are released. Repetitive cycles of uncommanded nose down stabilizer continue to occur unless the stabilizer trim system is deactivated.” (My emphasis.) Boeing is right. If it has an issue, you have to turn this robot off or it will get you. 

     Exactly five-seconds later, the MCAS forces the Lion Air Max 8 into another altitude-shedding dive. Neither pilot reaches for the two auto-trim cut-offs, protected by clear plastic covers low on the pedestal. Incredibly, neither Lion Air nor the FAA have informed them that standard recovery procedure on older 737s will not work on a Max 8. 

     “It would be a tough one to sort out,” another 737 captain admits. Especially, if you have never heard of MCAS and have no idea why the computer is overriding your commands. Why doesn’t the second pilot go ahead and open the plane’s tabbed manual of operating procedures? Maybe he's trying to help fight the computer. In mounting confusion and disbelief, every time Capt. Suneja pulls the nose up, the automatic anti-stall system shoves it back down. The descending tug-of-war between men and machine continues through more than two-dozen attempts to recover the aircraft. 

     Total flight time is 11 minutes. 

     0633: The last dip is straight-in from 5,000 feet. Flight 610 drops off the Jakarta Air Traffic Control radar, crashing into the sea 21 miles off the island of Java. Only the automatic Cockpit Voice Recorder and Flight Data Recorder survive.    


Every passenger airplane crash leads to improvements in equipment and procedures. But not if the pilots take the fall. “If we only blame the pilots, we will not have changed any of the fundamental underlying conditions” to “prevent this from happening again,” comments Captain “Sully” Sullenburger of miracle on the Hudson fame. 

     According to the Aviation Safety Network, based in the Netherlands, 2017 was “a record year for civil aviation with no deadly accidents on big passenger planes. However, there were plenty of incidents and safety issues on commercial flights,” writes Tom Dieusaert, author of Computer Crashes: When Airplane Systems Fail. There is no question that increasing automation is making flying safer. And more dangerous by keeping “airplane managers” out of an opaque loop. “Pilots find it increasingly difficult to cope with a lack of transparency of onboard systems,” adds Dieusaert. Systems whose complexly interacting, rules-based decisions can lead to overloaded human brains. And “Loss of Control in Flight.” 

     LOC-I, as air accident investigators term it, “has been the main cause accidents between 2010 and 2014: 43% of the 37 fatal accidents in that period originated after pilots did not understand what was happening in the cockpit.” In their 232-page report by France’s air crash investigation agency, BEA blamed the crash of AF447 on a crew disoriented by conflicting flight information, who attempted to follow faulty computer commands – including, “Flight Director indications that may lead the crew to believe that their actions were appropriate even though they were not."


“We don’t like that we weren’t notified,’’ said Jon Weaks, president of the Southwest Airlines Pilots Association, of MCAS following the Lion Air crash. “It makes us question, ‘Is that everything, guys?’ I would hope there are no more surprises out there.’’ Following the copycat Ehtiopian crash (see videos below) the Allied Pilots Association union was outraged that details about Boeing's hidden software band-aid were not included in the aircraft’s documentation. 

     “After this horrific Lion Air accident, you’d think that everyone flying this airplane would know that’s how you turn this off,” said Steve Wallace, former director of the FAA’s accident investigation branch.


The future is always a long ways off until it’s here. Dubai is about to introduce self-flying, helicopter taxis. A German manufacturer already offers an all-electric, fully autonomous model – just get in and tell the computer where you want to go. Full-size airliners currently on Boeing and Airbus drawing boards will fly from start-up to shut-down without human pilots, in so-called “free flight” mode. 

     If we get that far. The insects are disappearing, the poles are melting, and we’ve apparently broken the jetstream, loosing unpredictable year-round mayhem. Meanwhile, if Washington’s American-supremecist cabal makes good on their threat to position nuclear missiles within 10-minutes of Moscow, Putin promises to protect Russian citizens by targeting American and allied cities with similar payloads and flight times. At that point, with the Doomsday Clock tolling midnight, the window to spot incoming warheads, verify those threats, and launch a land-based counterstrike will be so close to instantaneous, launch authority on both sides will be placed under the control of smart machines. 

     And who knows what they'll be thinking.

Photo Credits:

ANZ Airbus 320

AF447’s Cockpit Voice Recorder on the seafloor for two years, more than 2 miles down.

737 Max cockpit showing unspecified controls to override MCAS computer during an emergency.