WASHINGTON - A White House plane carrying Michelle Obama came dangerously close to a 200-ton military cargo jet and had to abort its landing at Joint Base Andrews on Monday as the result of an air traffic controller's mistake, according to federal officials familiar with the incident.
Controllers at Andrews feared the cargo jet would not clear the runway in time for Mrs. Obama's plane to land, said the officials, who spoke on condition of anonymity because they are not authorized to speak for their agencies.
FAA officials confirmed that the first lady was aboard the White House plane but had no additional immediate comment. The first lady's office also had no immediate comment.
The Federal Aviation Administration, already dealing with a series of controversies involving controllers sleeping and watching a movie on the job, sent a team of investigators Tuesday to the Warrenton, Va., radar control center, where the mistake was made.
The first lady was returning from a television appearance and other events with Jill Biden in New York and was aboard a Boeing 737 that is part of the presidential fleet of jets when the error occurred on final approach to Andrews.
The controllers in the tower at Andrews recognized that the massive C-17 and the Obama flight, designated EXEC1F, a classification for a plane carrying members of the president's family, were far too close when the Warrenton controller handed off responsibility for the two aircraft.
They ordered the Obama plane to execute a series of S-turns in an effort to create a safe distance between it and the C-17, federal officials said. When those maneuvers failed to achieve the required distance between the two planes - and the Andrews controllers realized the cargo jet would not have time to get off the runway before the presidential plane arrived - they aborted landing of the Obama plane and ordered it to circle the airport.
Because an airplane's wake causes severe turbulence and, in extreme cases, can cause a plane that enters it to crash, the FAA has strict standards on how much distance controllers should maintain between planes.
A fully loaded C-17 can create such turbulence that the FAA requires a five-mile separation behind it. The presidential fleet 737 already was far closer than that when the handoff took place from the Potomac Terminal Radar Approach Control (TRACON) facility in Warrenton.
"The manager and tower controller at Andrews did several things to try to increase the separation on final 1/8approach3/8 before ordering a go-around," said a senior FAA manager familiar with the incident.
The FAA manager said the TRACON controller exhibited "really bad controller technique."
"Not only did he get them too close, he told the 1/8Andrews controller3/8 that they were farther apart than they were," he said.
When the handoff occurred, the planes were 3.08 miles apart, radar shows, but the TRACON controller told the Andrews tower that they were four miles apart. Before handing off, the TRACON controller warned Obama's pilot of potential wake turbulence.
In the Andrews tower, controllers already had identified "a serious loss of separation" but were reluctant to contact TRACON to point it out, officials said.
The Andrews controllers ordered the S-turns as soon as they assumed responsibility, but the two planes still grew closer. Finally, fearing the C-17 couldn't get off runway 19L in time for the Obama plane to land, they ordered EXEC1F to abort the landing attempt.
"In the grand scheme of things, events like this happen fairly frequently," said another federal official who works with the air traffic control system but is not authorized to speak publicly. "Unfortunately, this one involves a presidential plane."
Both go-arounds and errors by air traffic controllers are not uncommon. Controllers at Potomac TRACON, who direct more than 1.5 million flights a year to Washington-area airports, made a record 52 errors last year, an increase from 21 recorded in 2009.
In a memo to his staff last year, the facility's director cited "a definite increase in sloppy or poor adherence to SOP and handbook procedures."
Nationwide, recorded errors by controllers increased 51 percent last year, to 1,869.
In most instances - both locally and nationally - planes came too close but without risk of collision; in some, however, fatal consequences were narrowly averted.
In 2010, the National Transportation Safety Board took an unprecedented step by beginning to investigate the most serious mistakes by air traffic controllers.
Among the cases under NTSB review are near-collisions between a Boeing 737 and a helicopter in Houston, a Boeing 777 and a small plane in San Francisco, and an Airbus 319 and a Boeing 747 in Anchorage.
Staff writer Nia-Malika Henderson contributed to this report.