As computers become increasingly involved in flying modern airliners, asking human pilots to monitor those computers may be a recipe for disaster, researchers say.

They point to the 2013 crash of an Asiana Airlines flight at San Francisco, in which investigators determined the airplane, descending in an autopilot mode, slowed to a dangerously low speed that pilots in the cockpit failed to notice in time to avoid the accident.

Computer screens in modern cockpits present aircrew with huge amounts of information on automated functions such as speed, altitude and aircraft position, so how could the Asiana pilots have missed what was happening?

Easily, researchers say in a new study; in fact, they say, humans may be inherently bad at watching how computers work, making the monitoring task itself a recipe for failure.

The study involving a NASA research psychologist and a professor of brain and psychological science from the University of California, Santa Barbara, looked at why such monitoring failures are seen in even highly trained and experienced airline pilots.

The result, "Vigilance impossible: Diligence, distraction, and daydreaming all lead to failures in practical monitoring task," appears in the Consciousness and Cognition.

The researchers tasked 16 commercial jet pilots with monitoring a simulated routine flight in which cockpit automation was highly involved in navigating and directing the airplane.

Previous research has demonstrated monitoring computers — simply sitting and staring at digital screens — is a tiring process that can lead to inattention.

That was the case in the cockpit of the simulated flights, the researchers found.

"Our study really does suggest that vigilance is a very difficult task for people," says Jonathan Schooler of UC Santa Barbara. "Extended uninterrupted monitoring can be draining."

One possible antidote might be interruptions that can break up the monotony, such as having to talk to ground control, but the researchers noticed that such interruptions can also contribute to lapses in attention.

In addition, they say, is the all-too-human tendency for our minds to spontaneously wander when not otherwise occupied.

"So staring is draining, plus things come up which interfere with our ability to monitor, and our mind leaves the premises even when none of the other things are an issue," Schooler explains. "It's a trifecta of things working against effective monitoring."

The researchers suggest it might be better to hand over the task of monitoring computers as they function to ... other computers.

"This task of watching over a computer system while it works is incredibly trying, if not impossible, for a human being to do well," NASA researcher Steve Casner says. "You can try paying attention, and you can try taking brief breaks, but sooner or later you'll miss something important.

It may be a job better suited to a robot than to a human, he suggests.

"It's time to rethink the way we design these systems. Let the people do the stuff they are good at, and let the computers handle the mundane chores."