Do Computers Make Planes Less or More Safe?

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.

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