767 AST767 test airplane model. The Airborne Optical Adjunct (AOA) was built from the prototype 767 200. The aircraft was later renamed the Airborne Surveillance Testbed (AST). Modifications to the aircraft included a large "cupola" or hump which ran along the top of the aircraft from above the cockpit to just behind the trailing edge of the wings. Inside the cupola was a suite of infrared seekers that were used to track theater ballistic missile launches in