In the early days of aviation, airfields used a system of lights and other visual devices to communicate with pilots. Before the widespread use of radio, the rotating beacon was the primary communication system around both civilian and military airfields. Different light colors and frequency of display signaled various messages to pilots about condition of the field, the type of facility and other factors affecting their flight. Rotating beacons are still in use today, however, with radio and other communication development they have largely become obsolete. This example was originally atop the control tower at Chevalier Field, the original airfield on board NAS Pensacola, a site now home to the Naval Air Technical Training Center.