Calspan has been the worldwide leader in innovating, developing, and operating In-Flight Simulators (IFS) since 1947. Learjet IFS that have been used for over 30 years to train test pilots have found a niche in the last decade as effective Unmanned Air Vehicle (UAV) surrogates. The Learjet platform provides a safe way to test unmanned systems by providing a fully-programmable autonomous aircraft with an onboard safety pilot to take over in the event of a failure of the system under test. The Learjets have been instrumental in the development of Air Force and Navy Autonomous Aerial Refueling (AAR) and Sense and Avoid (SAA) programs. Configured as a Remotely Piloted Aircraft (RPA), the Learjets have been flown to touchdown by pilots “flying” from a ground station. The success of the Learjet as a UAV surrogate has prompted this capability to be extended to Calspan’s G-III Airborne Testbed which offers additional capacity to carry airborne systems as well as increased aircraft performance.