The US Federal Aviation Administration says a new method for defining reportable operational errors by controllers who allow aircraft in the en-route and terminal area to breach separation minima is intended to be a logical improvement to what had been a subjective process.
Officials say the change, developed over 18 months, will allow the agency to focus its resources on more serious operational errors. As well as defining minima, within which the events are no longer classified as operational errors, the new method also revisits the severity of the errors recorded.
Critics of the new system, spearheaded by the National Air Traffic Controllers Association (NATCA), say the modifications are merely a way to downgrade errors, making the agency appear to be performing a safer job. They also say operational tests of the new rules were not successful, as was claimed by the FAA.
Under the new system, the FAA on 25 June began allowing controllers a 10% margin around the 1,000ft (300m) vertical separation and 5nm (9.3km) and 3nm horizontal separation minima for en-route and terminal airspace, respectively, before they are reportable incidents. The standards are similar to those applied to pilots in terms of how closely they must follow assigned headings and altitudes.
The standards do not apply to wake turbulence separation, oceanic routes or operations on an airport, areas that will continue to observe previous standards.
If aircraft are beyond the buffer zone, closer than 900ft vertical or 3.5nm horizontal, the FAA declares an operational error and assigns it a severity category of A, B or C, where A events are severe and C incidents are benign.
The new standards put a premium on the proximity of the two aircraft, removing controller performance as well as closure rate and flightpath from the equation, says Tony Ferrante, director of the FAA's air traffic safety oversight service. The FAA is counting the total number of operational errors using the previous and new system through September, and plans to transition to the new standards in fiscal year 2008 if no issues arise.
Ferrante discounts NATCA's contention that tests of the new metric at six airports for a year were not successful because controllers were aware of the test and had "spread airplanes out" during the trials.
Source: Flight International
