The first operationally-capable OC-135B was assigned to the 24th Reconnaissance Squadron at Offutt AFB in October 1993. It is now fitted with a basic set of navigational and sensor equipment, and was placed in inviolate storage at the Aerospace Maintenance and Regeneration Center at Davis-Monthan Air Force Base near Tucson, Arizona in 1997. Two fully operational OC-135B aircraft were delivered in 1996 with the full complement of treaty-allowed sensors, which includes an infrared line scanner, synthetic aperture radar and video scanning sensors.