WASHINGTON >> The gyrocopter that landed on the lawn of the U.S. Capitol “apparently literally flew in under the radar,” Homeland Security Secretary Jeh Johnson said Thursday, as concerned lawmakers questioned how it was allowed to happen and why.

Johnson said it’s too soon to say whether Wednesday’s incident should prompt changes in security procedures. “I want to know all the facts before I reach an assessment of what can and should be done about gyrocopters in the future,” he said.

But lawmakers said the incident exposed a gap in security, especially amid revelations that the pilot, Florida postal worker Doug Hughes, was interviewed by the Secret Service almost two years ago. The agency apparently determined he did not pose a threat, said Rep. Elijah Cummings, D-Md., the senior Democrat on the House Oversight and Government Reform Committee. Cummings spoke Thursday with the Secret Service director.

“I think that there’s absolutely a gap, and it’s a very dangerous gap, with regard to our airspace,” Cummings said. “I don’t want people to get a message that they can just land anywhere. Suppose there was a bomb or an explosive device on that air vehicle? That could have been a major catastrophe.”

Johnson said the Secret Service passed along the information from the interview with Hughes, who was to appear in court Thursday afternoon, to “all of the appropriate law enforcement agencies.”

The tiny, open-air aircraft landed without injuries to anyone, but the incident raises questions about how someone could be allowed to fly all the way from Gettysburg, Pennsylvania, right up to the Capitol. Hughes has said he was making the flight to publicize his concerns about the corrupting influence of money in politics, and deliver letters to all 535 members of Congress on the topic.

“We are a democracy. We don’t have fences around our airspace, so we’ve got to find the right balance between living in a free and open society and security and the protection of federal buildings,” Johnson told reporters on Capitol Hill. “And so we want to stay one step ahead of every incident like this, but then again, you don’t want to overreact, either.”

Still, lawmakers questioned why, if authorities had been in touch with Hughes, no action was taken to stop him.

“My concerns are the prior notice that he was going to do this and the lack of response,” said Rep. Michael McCaul, R-Texas, chairman of the House Homeland Security Committee.

“These small aircraft or UAV devices concern me because they could go undetected and cause damage, so that’s something we’re taking a look at,” McCaul said, adding he might hold hearings on the issue.

Cummings and others also complained that they were not notified of the incident and that many first learned of it from the news media.

Johnson defended existing protocols for dealing with the restricted airspace over Washington, D.C., federal buildings and monuments.

“We’ve got a well-coordinated federal response to dealing with issues of those who penetrate the restricted airspace without permission,” he said. He said his first reaction on hearing of the incident was to ask, “What’s a gyrocopter?”

___

Associated Press writer Alan Fram contributed to this report.