Testifying for the first time in front of the Senate Subcommittee on Aviation, acting Federal Aviation Administrator Chris Rocheleau admitted that "something was missed."

The agency said it’s taking steps to lessen the risk of collisions, but lawmakers say too many gaps remain — and place part of the blame on the military.

The head of the Federal Aviation Administration told Congress during a hearing Thursday about a midair collision over Washington, D.C., that killed 67 people that the agency must do more to ensure flying remains safe.