Spot a strange aircraft flying around? Here's why: NORAD will be conducting flight exercises in the D.C. area, starting Thursday night through Sunday.

Flights are scheduled to take place in the Northern Capitol Region beginning at midnight, through 5 a.m. each day.

RELATED: Va. boys take flight in plane they built

The exercise, Falcon Virgo 18-04, is designed to train personnel, test a warning system, as well as “hone NORAD’s intercept and identification operations,” NORAD said in a statement.

Aircraft enthusiasts can keep an eye out for Air Force C-21 aircraft, Civil Air Patrol C-182 aircraft, and a U.S. Coast Guard MH-65 Dolphin helicopter, which will all be participating in the exercise.

These types of exercises have been conducted since the start of Operation Noble Eagle, NORAD’s response to the September 11 terrorist attacks.