A plane carrying First Lady Michelle Obama and Jill Biden was forced to abort a landing at Andrews Air Force Base on Monday after it drew too close to a military cargo plane sitting on the runway, federal officials said.
The Federal Aviation Administration said Tuesday that the plane was never in danger.
Obama and Biden, the wife of Vice President Joe Biden, were returning from New York on Monday afternoon aboard a Boeing C-40, an equivalent to a 737, when it approached the base while a 200-ton C-17 remained on the runway.
Planes are normally instructed to keep a distance of five miles apart, but the White House plane came within three miles of the C-17, officials said.
Controllers at Andrews ordered the jet carrying the first lady to delay its landing and circle the base.
The FAA said that controllers at Andrews told the plane to perform a "go-around" about 5:30 p.m. because the plane did not have "the required amount of separation behind a military C-17," said spokesperson Laura J. Brown. "The Boeing 737 landed safely after executing the go-around. The aircraft were never in any danger."
The FAA is investigating the incident. The first lady's office had no comment.
An Air Force public affairs official said Tuesday that the cargo plane on the runway "had gotten delayed momentarily, so instead of landing on the first attempt, they flew around the airfield once and then landed."
"Essentially, the FAA sent the first lady's aircraft to do a go-around," the official said.
Asked how common such episodes were, the official said, "It happens all the time on commercial airports."
Obama and Biden appeared Monday morning on ABC's "The View," program. The talk show was devoted to their Joining Forces program to support military families.
The FAA has been embroiled in controversy over air traffic controllers who have fallen asleep at their posts, and another who was caught watching a movie on the job. At least seven controllers have been suspended by the FAA.
On Sunday, Transportation Secretary Ray LaHood said controllers would now be guaranteed at least nine hours off to rest between scheduled shifts in an effort to ensure they remain alert on duty. The FAA also said it would end the practice of work shifts with a single controller.
Hank Krakowski, the FAA official charged with air traffic control, resigned last week.
Andrews Air Force base typically uses two runways but one was under construction, an official said.
The base, which sits in Maryland southeast of Washington, presents a heightened risk of midair collision, according to a document on its website.
"Our unusual mix of large executive support aircraft, low-flying helicopters, refueling aircraft and supersonic fighters contribute to the midair collision potential in the Washington D.C.-Baltimore area," the document says.
Peter Nicholas and Michael A. Memoli in the Washington bureau contributed to this report.