A drone, which was about two feet in diameter and weighed about two pounds, was operated by a unidentified government employee flew undetected by the White House radar system that was designed to detect larger flying objects such as planes, missiles and large drones.
It was unable to detect a smaller quadcopter that crashed into a tree on the South Lawn early Monday morning around 3 a.m.
It raised some serious questions about the integrity of the White House security and if it could be dealt with in time if it got in a dangerous proximity to President Obama. Josh Earnest, the White House press secretary, who is traveling with President Obama and Michelle Obama in India, said both Obama daughters were home at the time of the incident. The drone caused a temporary lockdown at the White House.
The drone was reported on Monday, as a Secret Service officer who was posted on the south grounds of the White House “heard and observed” the drone, the officer and others stationed at the residence were unable to bring it down before it passed over the White House fence and struck a tree.
The drone was too small and flying too low to be detected by radar, officials said, adding that because of its size, it could easily have been confused for a large bird. This raises the possibility of small drones that could also be used to launch chemical and biological attacks.
A photograph released by the Secret Service of the drone that crashed on the South Lawn looks partly broken. It appears to be a version of the DJI Phantom Aerial UAV Drone Quadcopter that is sold on Amazon.com starting at $479.
In a statement Monday afternoon, the Secret Service said a man had called the agency about 9:30 a.m. Monday to report that he had been the one controlling the drone when it crashed on the White House grounds.
“The individual has been interviewed by Secret Service agents and been fully cooperative, Initial indications are that this incident occurred as a result of recreational use of the device.”
Under federal law, it is illegal to fly a drone in Washington.
Brian Hearing, a founder of Droneshield L.L.C., which makes drone detection systems for prisons and nuclear facilities, said radar systems are effectively useless for catching such small drones. If the systems were set to be sensitive enough to detect the drones, they would also detect every bird or swaying tree.
Many small drones also have a GPS function designed to return the drone to its user if it loses contact with the remote control, Mr. Hearing said. But it is also simple to program the GPS function to fly directly to a specific address, such as 1600 Pennsylvania Avenue.
Technology is available to jam the signals of an approaching drone, Mr. Hearing said, which could cause the drone either to fall to the ground or to return to its user. Such technology, much of it made in China, is illegal for consumers and others to use, he said. Even more sophisticated jammers could allow those protecting the White House to take control of the drone from a user.