The Why Files The Why Files --

Praise the pilot: Commercial pilots making fewer errors!
3 JANUARY 2008

After the typical airport encounter, the near-strip searches, the endless warnings against "accepting foreign objects from strangers," the surly, overworked airline staff, you settle into seat 14E.

But as the hassle ends, the dread may begin. Strapped into an aluminum tube within a few yards of thousands of gallons of extremely flammable jet fuel, you're just moments away from a journey through thin air, at the mercy of some pilot who's locked into the cockpit.

Jet plane at the gate
What are the odds that this plane will make it to the other end safely? A new study shows that pilot errors have been dropping fast, but screw-ups on the ground (of all places!) are causing an increasing number of accidents. Photo: © David Tenenbaum

Flying a commercial airplane may scare some people, but it's astonishingly safe. Only 50 of the 750 million airline passengers in the United States died in 2006, while more than 42,500 died in car crashes.

About 42,600 people died in 2006, compared to about 42,100 in 1996
Auto death rates have increased somewhat over the past decade, but so has the volume of traffic. Almost 1,000 times as many people died in cars as in planes. So why doesn't driving spark the same kind of dread as flying? Data: National Highway Transportation Safety Administration

Now, a new study from Johns Hopkins Bloomberg School of Public Health soothes our fears about a key cause of avoidable problems: pilot error. The study found that their mistakes have declined by 40 percent on commercial airlines from 1983 to 2002. "Typically pilots are blamed for whatever goes wrong," says Susan Baker, a professor in the center for injury research and policy, who is also a general aviation (not commercial) pilot, "and we were interested in knowing if there had been a change in pilot error."

And what exactly does Baker consider pilot error? "It's something that did happen but should not have happened, based on the information that should have been available to the pilot."

One hand giveth...
To determine the role of pilot error, Baker hired a commercial pilot to examine records of 558 mishaps on U.S. airlines that occurred in the study period. The study concerned only scheduled, commercial flights, not general (amateur or small-plane) aviation, and the results indicate that somebody is doing something right in terms of pilot training and supervision: "We found, after a great deal of labor... that the rate of crashes related to pilot error had gone way down. If we look at the rate of poor decisions leading to mishaps, that is down by over 70 percent," she says. (Her study excluded deaths caused by crime and terrorism.)

Pilot errors in 236 mishaps, 1983-2002
Pie graph shows errors mentioned
When the pilot was to blame, carelessness (26 percent), flawed decisions (23 percent) and mishandling of the plane (21 percent) were the dominant causes. Data from Baker et al.

Some pilot error categories plunged like a jet with a stuck control flap: poor crew interactions, such as failing to heed the warnings of a subordinate, fell by 68 percent, and errors in handling wind and runway conditions fell by 78 percent. However, accidents due to carelessness or mishandling the aircraft -- like failing to understand how the plane would respond to controls -- did not change.

Although the overall rate of accidents was unchanged, the airline fatality rate continues to decline, Baker says. Most accidents were not caused by pilot error, according to the statistics: bad weather and clear air turbulence combined to account for 72 percent of airline accidents, while mechanical failure accounted for 21 percent.

And the other hand taketh away...
Despite the decline in pilot errors, during the study period, the total rate of mishaps remained at about 33 per 10 million flights. "There was an increase in things that may not involve the pilot, stuff going on on the ground; a ground vehicle striking the aircraft, or things that go wrong in the pushback" from the gate.

Pushback accidents -- which seem even more avoidable than flying boo-boos -- have grown from zero to 3 per 10 million flights, she says. "We now need to place greater attention to ground safety at the airport, on the vehicles that have to be present, baggage, fuel trucks, things that happen when aircraft are being pushed back from the gate. Those are areas where we have seen big increases."

In general, she says, these problems "are related to overloading, overtaxing the aviation system, and putting more flights into same number of airports and runways."

Expert: 'I don't know if we have gotten accidents to an irreducible minimum, but we certainly are close.'

Going down
What accounts for the declining rate of pilot errors? Better technology plays a role by helping pilots avoid bad weather. A second improvement emerges from better training, especially the focus on crew interactions, which helps pilots and other crew members work together to avoid or resolve problems. "I think captains and flight crews have become much more aware of the need for good communications," says Baker.

And does the happy news make her more comfortable as she settles into a seat on flight 451 for Denver? "I've never been afraid," she says, since flying is an extremely safe point-A-to-point-B technology. The 50 deaths in 2006 "ought to make people feel better when they step onto an airplane. Fatal airline crashes, thank God, are a rare event. I don't know if we have gotten to an irreducible minimum, but we certainly are close."

- David Tenenbaum

Related Why Files
• Why accidents happen.

• Susan Baker et al, Pilot error in air carrier mishaps: longitudinal trends among 558 reports, 1983 - 2002. Aviat Space Environ Med 2008; 79:1 - 5.

©2018, University of Wisconsin, Board of Regents.