Controllers, who are in the midst of a bitter contract clash with the FAA, say overall staffing levels and too many trainees on duty at any given time contribute to fatigue, burnout and breaks in concentration that make potentially fatal errors more likely -- a charge the FAA vehemently denies.

The controllers say low staffing is the reason they haven't replicated a streak of error-free work at McCarran that ended in 2000 and encompassed 20 months and 1 million airfield operations.

"When you have more errors, obviously, that margin of safety has been diminished," said Bryan Baker, a controller since 1988 who has worked at McCarran since 2002. "It is just a matter of time before you have a catastrophic event."

FAA officials say they are working hard to increase the number of controllers nationwide and in Las Vegas, where the authorized staffing level is 78 to 96 controllers between two facilities.

Including trainees, there are about 74 controllers at McCarran.

The FAA also disputes the correlation between staffing levels and the number of errors.

At McCarran, it points to operations in what's called the "tower," the 194-foot structure where controllers guide planes making final approaches, departures and taxiing on the ground.

The tower has a staff of 33 controllers who have logged two errors so far this fiscal year, which has three months remaining. Since 2004, the number of errors in the tower has been two or three annually, while staffing has shrunk from 43 to 33.

There was an exception in 2007 when there were five errors between 37 controllers.

The FAA also bristles at the suggestion that a higher percentage of trainees among the controller work force contributes to errors.

FAA spokesman Ian Gregor says the label "trainee" belies the reality of the workplace. In practice, there are eight possible jobs for controllers and an individual only works one of the positions after being fully trained. But that individual doesn't shed the "trainee" label until he or she is qualified at all eight positions.

"You could be certified in seven and training on one and still be considered a trainee," Gregor said.

Controllers see it differently.

Troy Verville, a controller at McCarran since 2000, said he witnessed an error he attributed to overwork as recently as Monday.

According to Verville, a single controller was working what had been three positions and erroneously cleared an aircraft for departure.

Verville said the controller mistakenly thought an aircraft being tracked by another controller had already departed, so he cleared another aircraft to depart.

A third controller overheard what was happening and pointed out the mistake. The maneuver was canceled, and no one was put in harm's way, Verville said.

"We got lucky. But I don't want to get lucky. I want to be safe," said Verville, who, like Baker, is also a representative for the National Air Traffic Controllers Association, the union for controllers. "The harsh reality is we don't have the appropriate number of people to do it as safe as we once did."

Feuding between FAA management and the controllers union has roots as far back as 1981, when then-President Reagan fired about 10,000 controllers he said conducted an illegal strike.

The mass firings created a bounty of ill will and prompted a need to find new people to do the jobs. The agency didn't recover in terms of staffing until about 1992.

The hiring surge also meant there would eventually be a retirement surge, which has come to pass in recent years.

To worsen matters, the contract with the controllers union expired in 2003. The pact was extended until 2005 but negotiations broke off, and in 2006 the federal government imposed a new contract for the controllers that included pay cuts and eliminated some extra pay opportunities.

The union is challenging the imposed contract but in the meantime controllers blame the deal for driving away experienced controllers and stretching staffs thin across the nation.

"In the tower, nowadays, we are basically working on a skeleton crew every day," Verville said.

In June, the ratio of trainees to fully certified controllers was the subject of hearings in Congress.

Members of a House aviation subcommittee heard testimony about a report from the Department of Transportation's inspector general that mentioned Las Vegas.

The report, which prompted criticism of the agency and media coverage of the hearing, stated there were 22 trainees and 22 fully certified controllers in the Las Vegas TRACON facility, which is responsible for flights farther away from the airport than what the control tower covers.

According to the report, the number of trainees at Las Vegas TRACON numbered 50 percent of the total, well beyond the 35 percent the FAA sets as a goal.

Unfortunately the report was wrong.

According to the FAA and the union, there are about 28 fully certified controllers and just 13 trainees, meaning only about 32 percent of local TRACON controllers are trainees.

A DOT spokeswoman did not return a message seeking comment on the report.

Although the report appears to have misstated the number of controllers in Las Vegas, both the union and FAA agree there need to be more controllers.

The FAA still plans to hire about 17,000 controllers nationally by 2017. But union leaders say pay cuts and other conditions from the imposed contract will undermine the effort.

They point to an exodus of experienced controllers as evidence that the impasse is spilling into the workplace.

"How we got here, I guess, is irrelevant at this point," Baker said. "We have got to stop the experienced controllers from going out the door."

Contact reporter Benjamin Spillman at bspillman@reviewjournal.com or 702-477-3861.