Don't be frightened if you see and hear military aircraft speeding overhead Thursday night in the D.C. area — it's all part of an exercise.

Don’t be frightened if you see and hear military aircraft speeding overhead Thursday night in the D.C. area — it’s all part of an exercise.

The North American Aerospace Defense Command (NORAD) is expected to conduct air exercises over the Washington area from Thursday night into early Friday morning. Flights are scheduled between midnight and 5:30 a.m.

NORAD calls the exercises FALCON VIRGO, which are designed to test airspace security — including hijackings and responding to unknown aircraft — around major U.S. cities like the District.

The organization warns that it conducts portions of the flight training at low altitude, sometimes at 2,500 feet above ground level.

The drill will include flights from F-16 aircraft, UC-35A aircraft, a Cessna 182T aircraft and an MH-65D Dolphin helicopter.

If weather interferes with the flights, NORAD will hold the exercises Friday night into Saturday morning.