Aloft

by William Langewiesche

  The Legacy’s cockpit voice recordings are closed loops two hours long. The one recovered from N600XL opens forty-two minutes into the flight like a curtain rising on a scene of normalcy, but with the Devil lurking just out of sight. It was 3:33 in the afternoon. The airplane was cruising on autopilot, about 150 miles south of Brasília, at the assigned altitude of 37,000 feet. Paladino, as copilot, was working the radio, checking into a new air traffic control sector. The sector was a subdivision within Brasília Center’s airspace. Brasília Center is a radar facility that controls traffic across a huge expanse of central Brazil, approximately to the northern boundary of Mato Grosso State. Paladino keyed a transmitter and said, ‘N600XL level, Flight Level 370.’ The controller’s response was garbled and incomprehensible. Paladino tried again, and this time the controller’s transmission was only slightly more clear. Lepore said, ‘I think he just said “radar contact.”’ Paladino took the captain on faith and radioed, ‘Roger, radar contact.’ To Lepore he added, ‘I have no idea what the hell he said.’ Lepore made no comment. Radio communications in cruise are largely routine, the necessary exchange had occurred, and pilots don’t tend to get excited. Back home in the United States they might have pushed the issue, alerted the controller to the poor quality of his transmissions, and tried to get him to switch to a better frequency or a closer antenna. They did none of that here. Was it cultural arrogance? Probably not. Was it linguistic timidity? Possibly, and perhaps compounded by the mental inertia that can lull pilots in flight. All was well for now, but in retrospect the crew’s lack of follow-up was not a good sign.

  To pass the time, they explored the airplane’s Flight Management System and the related flat-panel displays, as well as a stand-alone laptop computer loaded with Legacy flight-planning software provided by the Embraer factory. Paladino had the laptop. A passenger came forward. It may have been Sharkey, because he asked about the altitude as if he couldn’t simply read the instrument panel, as one would expect the others to have done. Whoever it was, Paladino greeted him with an overbright tone. ‘Hello! How ya doin’?’

  ‘Good. You?’

  ‘Very good. We’re just, ah, playin’. Trying to get used to the airplane.’

  ‘She’s flying nice, no?’

  The use of the feminine was awkward, but Paladino went along. ‘Yeah! She’s flying real nice!’

  They spoke about the weather, which for the moment was nice, too. The passenger left. Paladino got back to poking at the laptop. Speaking of the screen, he said, ‘Aw shit, I lost it…’

  Lepore said, ‘What’s the matter?’

  Paladino said, ‘I lost a page. Where’d it go? I musta hit something.’

  Lepore said, ‘Aw, it’s all right.’

  With nothing better to do, Lepore and Paladino kept fiddling with the computer. There was little reason to look outside. The earth lay far below as an irrelevant concern, and the surrounding sky was huge. Traffic at those altitudes was under radar control, and though other airplanes could be heard on the radio, the Legacy’s collision-avoidance system would warn of any that might stray near should the controllers make a mistake. That was the nature of the flight then under way. The cockpit was a cocoon. Lepore and Paladino were operating an inherently simple jet that had been stuffed with electronic capabilities – most of them nested, and therefore hidden from immediate view. The nesting of flight information, much of it non-essential, is a development now several decades old and somewhat out of control. It is driven on the one hand by market pressures to create clean cockpit displays, and on the other hand by the technical possibilities offered to overly enthusiastic designers and engineers. The problem for pilots is the idiosyncratic architecture of the systems that are created, the need to fathom the logic that has been applied, and the reliance on manuals laced with invented terminology to which practitioners are expected to submit their minds. In principle a pilot with sufficient time and patience can figure it all out in advance, but such pilots are rare, and Lepore and Paladino were not among them. They were stick-and-rudder men, confident in their control of the jet itself and comfortable with the first rule of aerial navigation, which is to point the airplane in the right direction and let it fly. In the Legacy, with its refined autopilot and its navigational systems, they had no problem doing that. The record shows that they remained at exactly 37,000 feet along the perfect centerline of the route they had been assigned. Meanwhile, they set about learning the airplane, as pilots must, through trial and error and practical use.

  The North American sales rep, Henry Yandle, came forward to visit. He had a hail-fellow manner that some passengers adopt in the company of pilots. Radio transmissions can be heard in the background, most in Portuguese, some from other airplanes, some from air traffic control. Yandle emphasized the need to give Sharkey a good flight. Eventually he said, ‘All right. How much longer, guys?’

  Lepore said, ‘Aw shit, good question,’ and laughed.

  Paladino said, ‘It’s fair enough.’

  Yandle said, ‘We were wondering because…’

  Lepore apologized. ‘We didn’t have it loaded up till after we got up here.’

  Paladino may have tried to pull up a clock. Speaking of the flight-planned duration, he said, ‘It’s three hours and twenty-three minutes from takeoff, so it’s gonna be, uh…’

  Lepore said, ‘Hour and…’ He began to finger his keypad, hoping to extract the answer from the Flight Management System. He said, ‘Still working out the kinks on how to work this stuff. This FMS.’ It now seems sad and even tragic, the reach for automation by these working pilots, their button-pushing response. They must have known at what time they had taken off. They had been in the air for forty-five minutes, give or take. The winds were not significant. With an additional ten minutes tacked on for arrival turns, this meant they probably had about two hours and forty-five minutes to go. It was the simplest sort of mental calculation and would have been accurate enough.

  Yandle tried to let it slide. He said, ‘Not a problem.’ But the question had been raised. Duty Time, Block Time, Local Time, Push Time, Release Time, Time Off, Time en Route, Time of Arrival, Fuel-Remaining Time, Void Time, Expect-This-or-That Time. There is also Coordinated Universal Time, called Zulu Time, which rolls nicely off the tongue.

  Lepore said, ‘Where’s the one that gives us Total Time?’

  Paladino said, ‘The Current, right?’

  ‘Current’ is the one you get from an ordinary watch. Lepore said, ‘Landing – that ain’t it.’ He kept fingering the keypad. ‘The arrival, the arrival, the arrival.’ He wasn’t giving up on the quest.

  But it was Paladino who had success. He said, ‘Here we go! Two hours and forty-seven minutes.’ He had unearthed Time Remaining.

  Yandle said, ‘Two forty-seven.’ The electronics had made it official.

  And so it went. This was an interval which might have been better spent in quiet concentration on the flight, but in private jets you don’t shut the door on the passengers. Yandle was a colleague, and Sharkey was important. The conversation continued as Lepore and Paladino tried to pull up weather information on the Flight Management System. They had a hard time finding it. They had similar trouble with the laptop. Their uncertainties were not to their discredit, and did not mean that they were reckless even to be flying that airplane, as has since been claimed. In retrospect they were perhaps too active in the cockpit. However, in this they were not alone. The best pilots are masters of minimalism who rely less on the equipment and more on their brains, but such pilots are rare.

  Airplane salesmen are different, because they profit from the addons. Yandle returned to the cabin and his guest. Alone in the cockpit, Lepore and Paladino kept fussing with the buttons as they approached the turn point over Brasília. The controller gave them a frequency change as they entered a new Brasília Center sector. That sector is large, stretching nearly 500 miles north to the edge of Brasília’s airspace, just beyond the Caiapós’ skies, where Manaus assumes contro
l. In the new sector the first frequency was 125.05 megahertz, which normally would be functional for about the next 250 miles. Paladino acknowledged the handoff, set the new frequency, and checked in with a standard call. ‘Brasília, N600XL, level, Flight Level 370. Good afternoon.’ The controller’s response was fast and strong. He said, ‘N600XL, squawk ident. Radar surveillance.’ Paladino answered, ‘Roger.’ Though the airplane had the entire large sector still to traverse, and all the radios were fine, this was the crew’s last full exchange with Brasília Center.

  Air traffic control in Brazil is a military function for historical reasons, none of them good. In the new sector, the controller on duty was an Air Force sergeant, aged thirty-eight, named Jomarcelo Fernandes dos Santos. His instruction to the Legacy to ‘squawk ident’ was a request for the crew to push a button associated with the transponder, which would highlight the airplane’s electronic symbol on the control-room console, making it easier for dos Santos to distinguish N600XL from other targets in flight. Why dos Santos felt the need is not clear, since the sector was particularly quiet at the time. In any event, high above Brasília, Paladino briefly neglected to comply. When he caught his error, he said, ‘Oh fuck, I forgot to do that.’ The ident button was on the Radio Management Unit, a control screen for the radios and transponder. Paladino pushed it. Belatedly, Lepore said, ‘ID’s right there.’ Paladino said, ‘I think I did it, yeah.’ Then he said, ‘I think you see that…’ He didn’t finish the thought. He said, ‘Oh shit!’ On the same device, the communications frequency had suddenly disappeared. But Paladino knew the number. He said, ‘Twenty-five-oh-five. That’s why I write it down.’ It was a good practice. Despite what engineers may think, there is no cockpit tool as solid as a pen. Paladino reset the frequency. Lepore said, ‘Yeah.’ Between the two men a subtle change was under way, and Paladino was ascending.

  Together they got back to the electronic maze, trying to calculate landing distance at Manaus, and takeoff performance for the following day. In the midst of this, the Legacy arrived over Brasília and was turned by the autopilot to track the airway, UZ6, on a course 24 degrees to the west of north. The Current Time was 3:55 PM.

  The pilots made no mention of the turn that the airplane had just made. That in itself is not surprising. But the Legacy was now cruising at 37,000 feet, in contradiction to the convention that would have shifted it to an ‘even’ flight level in the new direction. This was not illegal – and operationally it did not matter that the original flight plan had proposed a descent here to 36,000 feet. Indeed, the rules are very clear. Lepore and Paladino had been assigned 37,000 feet, and barring an emergency they were obligated to remain there until air traffic control approved a change. There had been no such instruction. They may have assumed that with so little traffic in the air the controller was doing them a favor and allowing an exception, as sometimes occurs in the United States. They certainly knew that they were in radio and radar contact with Brasília Center, and that their transponder was transmitting their altitude and showing it accurately on the radar screens. Nonetheless, 1,200 miles of airway now lay straight ahead – a long stretch to fly against convention – and it is odd that they did not comment on the unusual flight level or bother to verify it with the controller, all the more so in a Latin American system that felt loose to them and that they had reason to distrust. Their failure to speak up may never be fully explained. But it seems to have been a human thing, a slap-your-head lapse of the sort that invites the familiar question ‘How could I have been so dumb?’

  Explanations are harder for the performance of Sergeant dos Santos. His tasks as a high-altitude controller were similar to those faced by Internet gamers, but significantly slower and less complex, and although the consequences of his errors were potentially grave, the dimensions of the airspace overhead provided him with large margins for safety, even discounting cockpit-based collision-avoidance systems and the fact that some pilots do still look outside. In the United States a controller doing simulation research once mentioned to me the difficulty of directing two airplanes into each other even if you try. I answered that I was not surprised. Even the largest airplanes are small, and the starting point of collision avoidance has traditionally been a reality known as the theory of ‘the big sky.’ Dos Santos may not have thought about it as such, but his actions indicate a faith that airplanes left alone just naturally don’t collide.

  He sat at an electronic display that was as crisp and capable as any in the world. When the Legacy first checked in, just south of Brasília, it appeared on the screen as an encircled cross indicating an enhanced transponder return, with a vector line showing its direction of flight and a data block displaying its call sign and two altitudes. The first altitude was the transponder’s report of the Legacy’s current altitude, 37,000 feet, which Paladino had just confirmed by radio. It was followed by an equal sign (=) indicating a functioning transponder in level flight. This in turn was followed by the second displayed altitude, whose function is unique to the Brazilian system and operationally awkward. Elsewhere in the world that second altitude is the flight level to which an airplane has been cleared, a number entered manually by controllers when they call for a descent or climb. In Brazil it may be the same, but if no manual entry has been performed, automation takes over and the second altitude displayed becomes the one proposed by the original (archival) flight plan for the segment of the route. Does Santos must have known of the distinction. He was a working controller, and the nature of the second altitude is not difficult to understand. Nonetheless, on this particular day he seems to have become confused. When N600XL first entered his sector, just south of Brasília, the two altitudes were the same, both showing 37,000 feet with the equal sign between them, and the nature of the second altitude did not matter. But five minutes later, when the Legacy crossed overhead Brasília and turned left to track the airway, the second altitude display automatically switched to 36,000 feet, the original flight plan’s proposal, and a conventional level for the new direction of flight. Apparently dos Santos took this to mean that the Legacy had been instructed to descend, though he was the controller in charge and had made no such request. Mysteriously, he then ignored the indicator of the Legacy’s actual altitude – the transponder return, which showed the airplane still level at 37,000 feet. Against solid indications to the contrary, he believed that the Legacy had descended to 36,000 feet.

  I have tried to understand why. It may be that dos Santos would have so expected the Legacy pilots to speak up about flying at a nonstandard altitude that their radio silence got him to believe they were doing the conventional thing. But as errors go, this one was more than a head slapper. Furthermore, it was sustained, and it turned out to be contagious.

  For 50 miles beyond Brasília, the symbol for the Legacy showed a clear transponder return at 37,000 feet, and dos Santos did nothing about it. Then the Devil stepped onto the stage. It happened at 4:02 PM, when the Legacy’s transponder stopped transmitting. The loss was apparent in two ways on dos Santos’s screen: the circle surrounding the cross that marked the airplane’s position disappeared, and the sign between the two displayed flight levels (FL370 and FL360) changed from an equal sign to a ‘Z.’ The Legacy now existed as an unenhanced ‘primary’ target, a raw metal mass reflecting radar beams, with no altitude-reporting capacity. In the militarized environment of Brasília Center, however, an Air Force radar kicked in with a crude height-finding function intended to help fighter jets intercept hostile intruders who would naturally try to penetrate Mother Brazil with their transponders turned off. Because the Legacy was still close to the radar dish on the ground, the height finder was able to calculate the altitude correctly, and briefly showed it on the screen as 37,000 feet. Be that as it may, the loss of the transponder should have been no big deal. Indeed, transponder failures are fairly routine, and because they normally elicit a reaction from controllers (generally a request to the pilots to reboot the unit), this one might have gotten the two sides at
least to talk. The transponder problem would have been sorted out, and with it the question of altitude. Dos Santos, however, did not bother to call. It is as if he never noticed that the transponder had quit.

  Fifteen minutes later dos Santos went off duty. His replacement was another sergeant, age twenty-seven, named Lucivando Tibúrcio de Alencar. Dos Santos briefed him on the sector’s traffic, including a Legacy headed for Manaus – at Flight Level 360, he said. By then the Legacy was about 150 miles past Brasília, still within effective communication distance on the frequency assigned, but moving beyond the accuracy range of the military height-finding radar, which began to show the airplane’s altitude erroneously – coincidentally first at 36,000 feet, and then at variations so large that the Legacy would have had to zoom wildly to achieve them. This explains the later reports that the pilots had been stunting. Belatedly, de Alencar realized that the Legacy showed as a ‘primary’ target only, unenhanced by transponder and altitude reporting – but at soonest this appears to have been a full ten minutes after he came on duty, when he bothered for the first time to make a call. It was 4:27 PM, about a half-hour shy of Caiapó territory. The Legacy by then had flown for thirty-six minutes since the last communication with air traffic control, and for fully twenty-five minutes since the transponder had failed. It was roughly 250 miles north of Brasília; and already beyond the range of reliable two-way communication on the assigned frequency. When de Alencar called, the Legacy did not answer, because the transmission was not heard in the cockpit. De Alencar called again, to the same effect.