The sound of F-16s, helicopters and other aircraft in the skies above Washington early Wednesday will likely be an exercise designed to maintain the nation’s air defense network.

The operation known as Falcon Virgo is scheduled to take place between 3 and 5 a.m. and will involve planes and helicopters from the Civil Air Patrol, Air Force and Coast Guard fleets.

According to the Associated Press, a civilian aircraft will also conduct calibration flights between 12:30 and 2:30 a.m.

Falcon Virgo usually attracts the notice of Washingtonians, who sometimes find their sleep disturbed by the flurry of activity. We at Gridlock Central often receive phone calls from residents the next morning wondering what was happening.

The training exercise is coordinated by the North American Aerospace Defense Command and one of its three regional components, according to military officials.

The military has conducted such events throughout North America since the 9/11 terrorist attacks.