Boeing OC-135B Open Skies

The OC-135B Open Skies is a United States Air Force observation aircraft that supported the Treaty on Open Skies. A modified WC-135B, it flew unarmed observation flights over participating parties to the treaty. Three OC-135B aircraft were modified by the Aeronautical Systems Center's 4950th Test Wing at Wright-Patterson Air Force Base in Ohio, but only two were ever used. The first operationally capable aircraft was assigned to the 24th Reconnaissance Squadron at Offutt Air Force Base in October 1993, and two fully operational aircraft with the full complement of treaty-allowed sensors, an infrared line scanner, synthetic aperture radar and video scanning sensors, were delivered in 1996. The interior seats 35 people, and the cameras include framing cameras for low-altitude photography and a panoramic camera for high-altitude photography. In 2020 the United States announced its exit from the treaty and plans to liquidate the two jets.