Federal investigators released alarming details about controller errors that nearly caused a midair collision last year between a heavily loaded American Airlines jet and a military cargo plane off the East Coast, highlighting problems at New York’s premier traffic-control facility.

A report by the National Transportation Safety Board disclosed mistakes and miscommunications by air-traffic controllers, ending with the two big planes speeding on converging courses in the dark off the coast of New York. The jets, both at 22,000 feet, barreled directly toward each other for at least a minute without pilots seeing the other aircraft or realizing the extent of the danger.

At one point, controllers watched helplessly as alarms sounded in the cockpit of the Boeing 777, which had more than 250 people aboard, after a distracted controller lost track of the passenger plane while giving directions to another jet, according to the NTSB report, released last week.

The cargo plane’s wing tip passed about 2,000 feet to the left of the passenger jet–a distance of just 10 times the width of the Boeing 777. The planes normally should have been spaced at least 1,000 feet apart vertically and several miles laterally.

A catastrophe was averted, according to the report, when onboard collision-avoidance systems prompted the American Airlines crew to make three separate evasive maneuvers in a matter of seconds.

Safety experts consider the January 2011 incident significantly more serious than many other midair close calls that recently received public attention, including an incident last week that put three commuter planes too close to each other near Washington’s Ronald Reagan National Airport.

The incident is particularly worrisome, said government and industry experts, because the lapses occurred at what is regarded as one of the Federal Aviation Administration’s premier traffic control facilities, staffed by some of the most experienced controllers. The New York-area center guides planes through arguably the country’s most complex and busiest airspace.

The incident follows about a dozen scary midair close calls investigated by the safety board over the past two years. They included a US Airways jet with 138 people aboard that missed a Boeing 747 cargo jet by 100 feet vertically and one-third of a mile horizontally over Anchorage; and a packed United Airlines 777 taking off from San Francisco International Airport whose safety zone suddenly was penetrated by a single-engine propeller plane.

Safety board officials and outside experts believe such events partly reflect the strains of confronting heavy traffic, as well as controllers who were inadequately trained or worn out by extensive overtime.

Total controller errors reported by the FAA last year were about 80% higher than in 2007, though that includes mishaps on the ground and reflects more voluntary reports of lapses by controllers.

Nonetheless, by nearly all measures U.S. air travel is safer than ever, and statistically the most dangerous portions of a trip are those spent taxiing to and from the gate. Total slip-ups by controllers nationwide stood at about 1,900 for the fiscal year ended Sept. 30, 2011, basically flat compared with 2010.

The new report comes three months after a government watchdog substantiated allegations that FAA managers were slow to respond to safety complaints by controllers responsible for New York’s traffic corridor as well as other regions. Management of the New York center was revamped in 2011.

The near-collision also highlights coordination lapses as the Boeing 777 was passed from one controller to another during a climb to the southeast. The cargo jet, descending to the northwest, was communicating with a different controller handling a different sector of air space.

Safety experts believe the dangers from such errors are likely to increase as air traffic grows and the FAA consolidates facilities to transition to a new, satellite-based control system.

On Saturday, the FAA said the incident, which occurred about 10:30 p.m. on Jan. 20, 2011, some 88 miles east of New York City over the Atlantic, was serious enough to prompt procedural and other changes at the traffic-control center that handled the flights, especially tracking planes as they move among sectors.

According to the safety board’s report, a shocked traffic-control supervisor watched images of the two planes merge into one on a radar screen. She recalled seeing them “pass right over each other.”

The instant the crisis passed, the report says, a pilot on the American Airlines jet snapped at controllers over the radio: “That guy passed us now and that was not good.”

The captain of the American flight, bound for São Paulo, Brazil, later filed a written report recalling that on his instruments, the other plane’s location initially “appeared to be on the nose of the aircraft.”

The four-engine C-17 cargo plane had completed aerial refueling and, along with another C-17, was descending in formation toward McGuire-Dix-Lakehurst military base in New Jersey. The cargo planes didn’t take any evasive action, and all three jets landed safely at their destinations.

According to the report, the controller handling the passenger jet failed to comply with requests from a colleague to stop it from climbing above 20,000 feet, and then again above 21,000 feet.

The controller talking with the jet’s crew was distracted by reading back lengthy flight instructions to another aircraft in his sector, the report says.

The FAA declined to say whether any controller or manager was disciplined over the controller slip-ups, the details of which weren’t reported previously. American Airlines said it had no comment.

Last year’s emergency, according to the report, stemmed partly from the fact that the passenger plane remained in communication with one controller when it already had passed into a new sector handled by another controller transmitting on a different radio frequency.

The controllers used telephones to speak with each other to try to coordinate their instructions, but the report indicates confusion set in and automated collision warnings went off in the center.

One controller interviewed by safety board investigators, however, indicated controllers tend to ignore such facility alerts because they occur frequently due to the complexity and amount of traffic they handle.

In response to questions, the FAA said over the weekend it quickly took a number of corrective actions. “All front-line managers reviewed the radar replay of the events” and ordered extra staff training focusing on “hazards associated with aircraft in conflict” as they cross different sectors and pass from one controller to the next, according to the FAA.

Source: The Wall Street Journal


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