Don't be alarmed if you see aircraft models flying in patterns overhead the next few days.
The North American Aerospace Defense Commend will conduct calibration flights beginning Tuesday, March 20 and ending Friday, March 23 in the D.C. area.
The flights are said to enhance NORAD response capability, and will take place from 8 a.m. to 5 p.m. throughout the rest of the week.
NORAD says four small radio controlled models and four Light Sport Air crafts between 150 and 3000 feet above ground level in patterns. The radio controlled models will only fly in restricted airspace near Quantico.
NORAD began conducting these calibration flights after the terrorist attacks of September 11, 2001, when Operation Noble Eagle was created.