Planes flew too close to each other more often in the skies near Minneapolis-St Paul International Airport than at most of the nation’s other busier airports.
The Star Tribune explains that while MSP is the nation's 13th busiest when it comes to plane traffic, it experienced more problems than nine of the 12 busier U.S. airports. The latest figures show the MSP tower recorded 34 episodes of planes flying too close together in 2012. More than a third of the incidents were considered significant enough to prompt a special risk analysis by the Federal Aviation Administration.
FAA rules require minimum distances between planes. When planes fly closer than two-thirds of a minimum distance, the incident triggers a special review. Thirteen of the 34 recent incidents at MSP fell into that category. Hartsfield-Jackson Atlanta and Chicago O’Hare, the first- and second-busiest airports, reported 18 and seven such incidents.
The story adds that none of the 13 incidents at MSP that were reviewed was considered high risk. Three were identified as medium risk and the rest were classified as low risk.
Exactly how close can airplanes get? The FAA has complex rules, depending on the situation. The vertical separation minimum was changed from 2,000 vertical feet to 1,000 vertical feet in 2005.
The findings come in a report of the nation's air traffic control problems that the FAA compiled last September. At the time, Bloomberg News reported that close calls between aircraft in the nation's airports had increased in 2012. The story suggested the increase came as the government switched on more automatic monitors to track the incidents. The story said that there were 4,394 incidents of aircraft coming closer together than FAA rules allow in U.S. skies, up from 1,895 in the previous year.
The story linked at least part of the increase indicates to better reporting of errors and added that the most high-risk incidents declined as a percentage of total incidents. The results indicate the number of air-traffic controller errors logged by the FAA have been on the rise since 2009. The FAA attributed that increase to an initiative that encourages controllers to report errors without fear of punishment.
The Star Tribune's front-page story includes a first look at local numbers. The figures come as the result of a Freedom of Information Act request by the Minneapolis newspaper. The FAA didn’t offer a specific reason for the higher numbers at MSP. But after speaking with aviation experts and current and former air traffic reporters, the newspaper concluded that the airport’s layout, urban location and heavy reliance on two runways can "...create a more challenging environment than airports with more room to maneuver."
The number and arrangement of runways at MSP were a factor in previous reports on errors. Eighty percent of MSP's traffic uses parallel runways that face northwest and southeast to take advantage of prevailing winds. They are crossed by a third runway. A newer fourth runway facing north and south handles some traffic that otherwise would use the parallel runways. Jim Swenberger, who worked for three decades as a controller, supervisor and investigator, told the Star Tribune that the runway design creates problems for controllers if a plane cancels a landing on the new north-south runway and turns toward the parallel runways.
Meanwhile, KSTP reports that citizens group MSP FairSkies is pushing for new laws to to toughen environmental studies and reduce allowable decibel levels for flights over MSP. The group supports several proposed laws at the Minnesota State Capitol that would slow down expansion plans at the airport. Air travel at MSP International Airport expected to increase significantly over the next 15 years.