In collaboration with the U.S. Air Force Research Labs (ARFL), Booz Allen, Microsoft and Inhance, we designed and programmed an MRO AR application running on HoloLens AR headset. A maintainer is trained via step-by-step instructions on repairing an aileron actuator on the F-15C aircraft. Augmented holographic instructions are overlaid on real (and virtual 3D) parts.