By Gerald Traufetter
Until they finally managed to reboot the failed system, the pilots had to rely on the emergency instruments, which have been located on the instrument panel since the early days of modern aviation, such as an artificial horizon and an altimeter based on barometric pressure.
In the latest generation of airplanes, the emergency messages also appear on a screen. Pilots refer to the modern-day cockpit, riddled as it is with monitors, as the "glass cockpit," unlike the cockpit of the past, which pilots affectionately called the "clock shop." If the Budapest flight had been part of the new generation of aircraft, would the monitor displaying the error messages have gone dark, as well?
In February 2005, the computer that monitored and controlled fuel levels on board an A340 failed en route from Hong Kong to London. One engine shut down and a second one stalled, but because the A340 has four engines, an emergency landing in Amsterdam went off without a hitch.
These mishaps raise the question of whether we will ever be able to rule out the possibility that an unrecognized error is lurking somewhere deep in the network of computer units, in the cacophony of programming languages and the interplay of zeroes and ones. For instance, when a Malaysia Airlines Boeing 777 went out of control four years ago, experts later discovered that a software update was incompatible with the preinstalled programs. "It would make me very worried about the future if we didn't get these kinds of problems under control," says NTSB expert Haueter, who is calling for new standards in the certification of automated systems on aircraft.
A Lack of Expertise
Peter Ladkin, an expert on software safety at the University of Bielefeld in north-central Germany, is working on a similar project. He is critical of the lack of expertise and what he says is incorrect methodology in the inspection and approval of new technology touted as "intelligent." "At the most, one failure per billion flying hours is guaranteed, and then the system goes haywire two times during a single flight, and again a few months later," he says, referring to the Qantas incidents.
Even system developers are increasingly stumped by the complexity of the computer networks they created. After an accident, it is often the case that only experts from the manufacturing company can reconstruct what kind of an error could have occurred in the computer -- a process that can sometimes take weeks. "The pilot, on the other hand, sometimes has only seconds to save his life and the lives of his passengers," says Ladkin, a pilot himself.
He also believes that it is highly problematic for the manufacturer of an airplane or a computer component to be entrusted with the investigation after an accident, because no one else can figure out the software. "This limits the perspective when searching for the cause," says Ladkin -- probably because no one wants to accept the blame.
Martyn Thomas, a British software safety consultant, agrees. "Computers have moved too far away from the people who are supposed to be operating them." What is needed, says Thomas, is a cockpit that is configured to allow a human being to intuitively take the right steps in an emergency.
The sidestick on the Airbus, for example, is controversial among pilots. It has fundamentally changed steering an airplane. In the past, the pilot's and co-pilot's control columns were connected to the same mechanical system. As a result, either of them could always feel what the other one was doing. This is not the case on Airbus's modern jetliners, in which the pilot's movements are ordinarily offset against those of the co-pilot. If both press the sidestick in the same direction, this increases the motion of the rudder. But if one pilot steers to the right and the other to the left, the two movements cancel each other out.
There is a button on the sidestick that allows one of the pilots to assume full control of the steering system. But the pilot faced with an emergency must remember to press the button. Besides, the switch takes a brief moment to go into effect.
Nevertheless, electronics have undoubtedly simplified the routine of flying. Gone are the days when pilots had to carefully guide an airplane into the right position, adjusting the thrust and using the rudders to steer against the wind. Passengers also benefit from the flying comfort that modern jets offer. The computer usually ensures that bumpiness during turbulence remains mild. In addition, digital technology has made aviation more efficient.
For example, landing is so automated that engineers have deliberately left it up to the pilots to extend the landing flaps and landing gear, even though the computers could handle this just as well. "This is purely to keep the pilots alert," explains aviation professor Hüttig.
"An Immense Workload"
Strong nerves, however, are all the more crucial when problems occur. Suddenly the two people in the cockpit are inundated with an abundance of control and warning messages that can hardly be processed. Granted, the system does arrange failures according to their urgency. For example, a faulty toilet flushing mechanism will appear at the bottom of the error menu. "In an extreme case, this requires pilots to understand the structure of a system that is hardly comprehensible," says Iberia pilot Hoyas. He cites the Air France Airbus crash as an example. "The error messages indicate an immense work load."
The operating manual does provide instructions on what to do in many cases of trouble. But how can someone repair a digital, multiple organ failure while under stress and flying through a storm at night? "And, in the end, the manufacturer says: 'Well, there were instructions for that,'" says Hoyas.
Another fatal problem, according to Hoyas, is that pilots increasingly lack the necessary training. "Some long-haul captains perform a handful of takeoffs and landings a month," says Hoyas. Once the computer is humming away, there is little left to do during the flight itself. The classic concept of flying, with a control column and thrust levers, is largely a thing of the past.
At the same time, young pilots are required to have less and less flying experience. The boom in discount airlines and the unbridled growth of aviation in Asia have led to training in the air being cut in half, from 300 to 150 hours.
And that number is expected to go down even farther. Under the new "Multi Crew Pilot License" system, pilot candidates will train in simulators more than in real life in the future. "Soon there will be co-pilots in the cockpit with only 70 hours of real flying experience," Hoyas says critically.
Faced with rising costs, airlines welcome the fact that the work of human personnel is gradually being delegated to computers in the cockpit. Even people at Airbus don't deny this. "Some companies justify reducing their training with the argument that they have purchased a modern aircraft with every conceivable form of safety technology," says an Airbus executive, although he denies the suggestion that Airbus uses this potential savings opportunity as a selling point.
The automation of aviation is moving relentlessly forward. Engineers are currently addressing what is perhaps the most dangerous phase of flight: the moment of touchdown, when people who are afraid of flying are already relaxing and, especially on charter flights, the passengers tend to break out in applause.
A new technology uses the exact position and topographic airport profile to measure whether the aircraft is gliding onto the runway correctly: not too high, not too low, not too soon, not too fast.
When the wheels have touched down, a second system controls the brake force, ensuring that the aircraft can turn off at the correct runway exit. Although the decision to abort a landing still rests with the pilot in the current configuration, "the system could already land the plane entirely on its own today," says Holger Duda of the DLR in Braunschweig.
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