The pilot was having trouble lining up the commercial airliner for landing at Denver International Airport late one windy night last May.
The plane’s speed brakes — spoilers on the wings — were partially extended to counteract a strong tailwind. The jet began losing speed. Distracted by preparations for landing, the pilot gunned the engines while the brakes were still deployed.
“For 10 seconds my situational awareness was lost,” the pilot wrote in an incident report. The pilot was able to correct and land safely.
It was a potentially dangerous lapse at a critical time. But it wasn’t a rare event at DIA or any other airport. Human factors were cited as the primary problem in 74 commercial aviation safety incidents reported at DIA since 2005, according to a NASA database of voluntary, anonymous reports from pilots and others.
Pilot error has been the leading cause of commercial airline accidents by a wide margin for many years. The Colgan Air commuter-plane crash near Buffalo, N.Y., just over a year ago that killed 50 people highlighted the issue as well as troubling trends in pilot training, scheduling and hiring at regional carriers. The National Transportation Safety Board issued a report that primarily blamed the captain for the crash.
Last week’s midair collision of two small aircraft over Boulder highlighted that human error also is the leading cause of general-aviation accidents. Both pilots and a passenger died. Crash investigators said they will look for clues in the wreckage and focus on the pilots’ procedures.
Though advances in technologies that assist commercial pilots — alerting them, for example, to potential conflicts with other aircraft or mountains — have helped reduce accident rates over the past few decades, human factors stubbornly remain at the center of most airline disasters.
In the cockpit, those factors vary greatly but can include distractions, whether work-related or personal; inadequate training; fatigue; poor communication between pilots; and inattentiveness. Pilots groups are calling for overhauls in training and scheduling, at regional airlines in particular, to combat these issues.
Flight-crew issues were the primary cause of two-thirds of fatal commercial and business plane crashes worldwide from 1997 through 2006, the United Kingdom’s Civil Aviation Authority reported last year. A 2006 Federal Aviation Administration study found that from 1990 to 2002, 45 percent of major airline accidents in the United States and 75 percent of commuter-carrier crashes were associated with human error.
After decades of decline, the commercial jet accident rate flattened out during the past five years, leading many aviation experts to believe that the biggest future safety advancements will come from reductions in human error.
But it’s a complex area of research — involving the study of psychology, decision-making, crew member interaction, training, cockpit design and the relationship between humans and sophisticated automated systems — that sometimes takes a back seat to more obvious safety threats.
“Can the accident rate be further reduced substantially? Absolutely yes,” said Robert Dismukes, chief scientist for human factors research and technology at NASA’s Ames Research Center in Moffett Field, Calif. “But this will require better understanding of the underlying causes of human error and better ways of managing human error.”
Pilots are concerned that cockpit automation has eroded basic flying skills that may be required in an emergency.
“The more automated things get, the more difficult it gets to spend 16 hours at a time in the cockpit and stay engaged, whether it’s one flight or a series of flights over that period of time,” said Paul Rice, an airline captain and a vice president of the Air Line Pilots Association, a union representing 53,000 pilots. “It’s a difficult task. That’s where study of human factors will make gains in the next few years.”
Smaller airlines, bigger woes
The Colgan Air crash focused attention on pilot training, screening, scheduling, hiring, pay and professional conduct at regional carriers. The pilots lost control of the turboprop as it approached the Buffalo airport in icing conditions.
The National Transportation Safety Board faulted the captain for responding inappropriately to a stall warning, among other errors, and made a series of recommendations to the FAA to tighten oversight of commuter carriers.
The FAA said last month that it is keeping closer tabs on regional pilot training and has pushed commuter airlines to better track weak pilots. The pilots union criticized the safety board for placing the blame almost solely on the Colgan Air pilot rather than on an array of causes, including cost-cutting industry practices that the union says promote fatigue, poor training and inexperience.
“We need to know why mistakes were made, not just that mistakes were made,” Rice said.
The union is calling for an overhaul of airline pilot training to encompass more flight-simulator time, use of high-tech motion simulators that better train for emergencies, more flying without aid from automated systems, enhanced command skills and mentorship of less experienced pilots.
At regional carriers, which are under pressure to cut costs from the major airlines that contract their services, poor training can combine with relative inexperience to create unprepared pilots, Rice said.
But the majors also are trimming their training requirements to reduce costs. When Rice began flying for a major airline 30 years ago, initial training took 3½ months, he said. Now it takes about 3½ weeks. Ground school and simulator time have both been trimmed, and pilots are expected to self-train using DVDs at home before showing up for retraining, he said.
An industry spokesman said airlines are cutting costs but aren’t compromising safety.
“Does he cite anything, beyond his opinion, about how the number of hours and mechanism of training affect safety?” said David Castelveter of the Air Transport Association, an airlines industry group. “Is there a result, an analytical result, that makes flying any less safe? We believe no.”
The industry has worked closely for many years with the FAA, the pilots and others to study human factors, Castelveter said. Airlines gather information on crew performance through confidential employee reporting programs and cockpit ride-alongs and by analyzing flight data, he said.
Major and regional airlines also closely follow FAA training standards, and many exceed those, Castelveter said.
“The FAA approves our training programs,” he said. “If the FAA believes those programs are inadequate, we will participate in any task force or review that needs to take place.”
Human error at all levels
Pilot error is not confined to the regional airline industry. Though major airline pilots have the benefit of more experience, automated flight-deck systems and bigger employers, they also are vulnerable to human error. Aviation experts say raising the bar for pilot performance across the industry is equally important.
There hasn’t been a major-airline crash with passenger deaths in the United States since 2001 — compared with four such accidents involving regional carriers. But the last catastrophe involving a major U.S. airline, the 2001 crash of an American Airlines jet in Queens, N.Y., that killed 265 people, was blamed primarily on a pilot’s inappropriate response to wake turbulence. More recently, a handful of accidents, close calls and other incidents involving mainline jets illustrates the seriousness of the problem.
The National Aeronautics and Space Administration’s Aviation Safety Reporting System database contains thousands of incident reports attributed to human factors. The Denver cases range in severity from taxiway conflicts to a near-collision in 2007 of an incoming jetliner with a turboprop that strayed onto the runway.
Many cases involve pilots recovering from unexpected events such as strong winds or potential conflicts with other planes. The December 2008 crash at DIA of a Continental Airlines jet taking off in heavy gusts isn’t in the database, and investigators haven’t determined whether crew error played a role.
In the May 2009 incident, the pilot said the plane was never in danger, but he called it a “valuable lesson learned about habit patterns, possible fatigue, distractions and how they can create a quick error chain that can snow ball based on environment and circumstances.”
Perhaps the most well-known U.S. airline accident in recent years was the successful ditching of a US Airways jet on the Hudson River in New York in January 2009 after bird strikes took out both engines. The crew, headed by 42-year veteran captain Chesley Sullenberger, glided the plane to touchdown on the river, saving everyone on board.
The incident showed pilot skill at its highest level — the kind passengers hope exists in the cockpit each time they board a commercial flight. But there were other nonfatal incidents in 2009 that raised troubling questions about crew performance and training.
• On Oct. 19, a Delta Air Lines flight from Brazil landed on a taxiway instead of a runway at Hartsfield-Jackson International Airport in Atlanta.
• Two days later, a Northwest Airlines crew overflew its destination, Minneapolis-St. Paul International Airport, by 150 miles. They were out of radio contact with air-traffic controllers for much of the flight from San Diego. The pilots have said they were using laptops and discussing company scheduling policies.
• An American Airlines jet skidded off the runway during a storm in Jamaica on Dec. 22. It had landed about 4,000 feet into the 8,900-foot runway. The FAA increased oversight of the airline after the accident and two incidents in December in which wings touched ground during landings.
Automation pros, cons
Bill Voss, president of the Alexandria, Va.-based international nonprofit Flight Safety Foundation, said that worldwide, more accidents reflect the troubling trend of pilots responding inappropriately to or not recognizing automation failures or anomalies during flight.
Two recent deadly examples were a Turkish Airlines jet that hit ground before the runway in Amsterdam in February 2009 and the Air France plane that crashed into the Atlantic Ocean amid severe thunderstorms in June.
An altimeter failed on the Turkish Air flight, prompting the autopilot to prematurely power down the engines. By the time the pilots realized what had happened, it was too late to avoid a crash.
It’s less clear what happened on the Air France flight, but investigators said the plane’s air-speed indicators were giving faulty readings before it went down. That’s a dangerous situation but is not by itself unrecoverable by an alert crew that is trained for it, Voss said.
“I can’t imagine how many people have been saved by automation, but what we haven’t done a good job of is evolving our training with the changes,” he said. “Any technology comes with new modes of failure, and we’ve never assessed and trained for these new modes of failure.”
“Loss of control” accidents — in which the crew was unable to recover from an unexpected event such as engine failure or a stall — accounted for 42 percent of commercial aviation fatalities worldwide from 1999 through 2008, more than any other cause, according to the Boeing Co. and the Commercial Aviation Safety Team, a joint effort between the FAA and the aviation industry.
In the U.S., loss-of-control accidents declined during the past decade, accounting for 29 percent of all fatal commercial airline crashes from 2000 to 2009, down from 34 percent in the previous decade, according to FAA statistics.
Automation and proficiency
One way to reduce accidents would be to increase remedial pilot training in basic flying skills that have been eroded because of automation, said Mike Gillen, a veteran Denver-based commercial airline pilot who has researched the issue.
Gillen tested 30 commercial airline pilots on five maneuvers, including takeoff, instrument-based approach, aborted landing, holding pattern and engine failure at takeoff. On average, pilots flew below the airlines’ required standards and in some cases committed serious errors, Gillen said.
“I’m not saying that airline pilots aren’t proficient at flying the planes with the equipment on board,” he said. “I am saying that when the equipment is severely degraded, they can have trouble flying the airplane.”
Castelveter of the airline association said automation failures are rare because of built-in redundancies in flight systems.
The FAA is planning a meeting with airline leaders in April to discuss how the companies incorporate human-factors issues in their training, agency spokeswoman Alison Duquette said. Some airlines have begun encouraging pilots to manually fly their planes more before and after cruise to keep those skills fresh, said Rice of the pilots union.
“The mechanics of an airplane are highly reliable. The avionics and the instrumentation are highly reliable. But it can still fail,” Rice said. “The last and best safety device in the airplane is a well-trained, well-qualified pilot.”
Greg Griffin: 303-954-1241 or ggriffin@denverpost.com
