By Ashley Halsey III
Washington Post Staff Writer
Monday, July 5, 2010; A01
A 120-seat United Airlines plane bound for Reagan National Airport from Chicago narrowly avoided colliding with a business jet departing from Dulles last Monday, the latest of 22 recent potentially dangerous mistakes by air traffic controllers who command the skies above Washington.
The United Airbus 319 was within 15 seconds of colliding with a 22-seat Gulfstream jet before, an internal FAA document shows, an onboard warning system ordered the pilots to take evasive action. The United pilot reported seeing the smaller jet pass just behind him.
"It's the air traffic controller that's supposed to control this situation, not" the onboard warning system, said John DeLisi, deputy director of aviation for the National Transportation Safety Board. "When it had to kick in and do its thing, that wasn't a good controller."
The number of times planes have come too close for comfort in the region in the past six months has surpassed the total of 18 the previous year. Nationwide, air traffic controllers committed 949 errors last year.
The incidents come as a new cadre of controllers is being trained to replace a generation of retiring controllers, a legacy of the 1981 strike during which President Ronald Reagan fired virtually the entire staff of controllers. Forty-nine of the 177 controllers who handle in-flight traffic for the Washington region, the third-busiest airspace in the nation after New York and Los Angeles, have yet to be certified in all aspects of their job, according to the FAA.
FAA regulations require that planes be separated by at least three miles or 1,000 feet in altitude. At cruising altitude, a passenger jet traveling 500 mph will cover a mile -- 5,280 feet -- in 7.2 seconds. As they climb to or descend from those heights, speed is lower: A mile passes in 18 seconds at 200 mph, 14 seconds at 250 and 12 seconds at 300.NTSB investigations
The NTSB is investigating almost a dozen midair near-collisions that have occurred nationally since it began to mandate that they be reported in March. They include an incident 24,000 feet over Maryland on March 25, when a Continental Airlines 737 came within about a mile of colliding with a Gulfstream jet. The traffic was under the direction of a controller who had been on the job for almost three years after graduating from a college program. She was still in training.
"I am very comfortable that we run an incredibly safe system," said J. Randolph Babbitt, head of the Federal Aviation Administration.
The incidents over Washington, detailed in internal FAA documents, have ranged from planes being ordered into the dangerous, turbulent wake of jumbo jets to mistakes that could have led to midair collisions involving commercial airliners carrying hundreds of passengers.
Among the closest calls: A Continental 737 waiting to land at National came within 3,900 feet of a military plane that had taken off from Andrews Air Force Base. An 80-passenger shuttle jet taking off from Dulles International Airport was turned directly into the path of a commuter jet on track to land at National, and they continued on that course until onboard collision-avoidance systems went off. A JetBlue Airways 150-passenger Airbus was directed into the path of a Beechcraft charter jet as both were making final approach to Dulles. They passed within about 3,600 feet of each other.
Last Monday's incident occurred as thunderstorms disrupted the normal flow of air traffic in the region, requiring controllers to send planes under their direction into airspace supervised by their colleagues. The United pilot radioed that he had "pulled up twice, hard" to avoid a twin-engine Gulfstream business jet that had come within several hundred feet.
The controllers handling the two planes were sitting two radar screens away in the Warrenton Terminal Radar Approach Control (TRACON) building. When the United controller needed to send the plane into the airspace under a colleague's supervision, he did a "splat-splat," highlighting his United plane in yellow as it made the move. But there was no oral communication.
"In thunderstorms it's often necessary to make heading changes that put a plane in somebody else's airspace," said DeLisi, whose agency reviewed the incident. "There's a gentleman's agreement that allows for that. On this particular day, one of the gentlemen thought that agreement was in place, and the other wasn't aware of that fact."
That triggered the onboard Traffic Alert and Collision Avoidance Systems (TCAS), which DeLisi called "the last line of defense against a midair collision."
In all four incidents the planes came so close that they merged into a single dot on the radar screens of the air traffic controllers based at the FAA's Potomac TRACON facility.
"The ones we're mostly interested in are the ones where there was a risk of midair collision," said DeLisi, explaining why the NTSB recently mandated that the FAA share the error reports. "We're mostly interested in cases where no corrective action appeared imminent by the controller and the TCAS kicked in."Traffic management
The air traffic control system involves a latticework of responsibilities in managing aircraft from boarding gate to arrival. The people in the control tower direct planes on the ground. TRACON controllers take over once they are airborne and then release them to the tower when they are within seven miles of landing. Once planes reach cruising altitudes, another group of controllers takes over for the long haul.
The system is integrated and linked to every aircraft, but progress requires handoffs among controllers that can be communicated electronically and orally.
TRACON is traffic management at its most intense level. Particularly in a region such as Washington, where there are four major airports -- Dulles, National, Baltimore-Washington International Marshall Airport and Andrews -- that communication becomes most vital. During fiscal 2009, the calendar used by the FAA, 742,463 aircraft -- an average of more than 2,000 each day -- operated in the Potomac TRACON airspace.
Nationally, the number of operator errors in fiscal 2009 was lower than in the previous year, reflecting a drop of almost 7 million in the number of flights overall. But the number of errors for fiscal 2009 is significantly higher than that of fiscal 2007, when there were almost 10 million more flights.
Babbit attributes the increase to more voluntary reporting of their errors by controllers after he issued a rule change that they should "only rarely be removed" from managing flights while their errors are investigated. None of the 177 controllers at Potomac TRACON have been decertified this year, the FAA said.'Lessons Learned'
There is no question, however, that the mass turnover in the controller workforce has had an impact on the system.
Controllers are required to retire at 56 or after 25 years of service. As a result, the mass hiring in the years after the Reagan firings has brought about mass retirements in recent years.
At the same time, a pay freeze in effect until recently gave experienced controllers no financial incentive to move from less hectic regional airports into the more complex and pressurized environments of the major hubs that include multiple busy airports.
Without that farm-team system to draw on, the FAA turned to recent training school graduates, controllers leaving military service and people with an aptitude for the profession to fill jobs at major TRACONs, according the FAA.
"You can't just leave them vacant," Babbit said. But with a new contract in place, "that era is behind us and we can entice more experienced controllers."
They all receive FAA training. Once they move into a TRACON facility, novice controllers must qualify in each of the center's sectors and duties before becoming fully certified. Other controllers supervise their work.Certification
Forty-nine of the 177 controllers at Potomac are working toward full certification.
One of them, known as a "developmental" controller, was handling traffic at National this year on a day when bad weather and wind shifts caused chaos in the system, leading to a pair of error reports. The wind shift required the airport to reverse the direction of operations.
"The developmental, who had not yet experienced a runway change, now had 11 aircraft on frequency," the FAA's internal report said. "The developmental continued to work the combined positions, which quickly became disorganized."
After the developmental ordered a commuter jet to follow dangerously close to a Continental plane, the supervising controller stepped in to order the Continental flight to break off its approach. Then the supervisor ordered the controller who had been assigned to instruct the developmental to take her place at the radar. The more experienced controller made the second mistake, misjudging the speeds of two approaching planes.
Kept aloft longer than expected by the confusion, some of the planes ran low on fuel. After a review, the internal report underscored communication failures.
"Don't keep secrets, especially during critical and disorganized operations like an unexpected runway change," the document said under the heading "Lessons Learned." "These two easily avoidable issues cost the entire group of aircraft possibly 45 minutes of flying time, maybe even more. During this change of operation and recovery there were THREE declarations [by pilots] of minimum fuel that went unacknowledged by our controllers.
"During critical and disorganized operations just one or two mistakes can adversely escalate an entire situation."