The image above shows the view from the cockpit of one of these aircraft after mid-air refuelling.
Below is an image of an NASA F-15 from a research aircraft – this one trialling a new flexible wing.
Chase pilots are in constant radio contact with research pilots and serve as an “extra set of eyes” to help maintain total flight safety during specific tests and maneuvers. They monitor certain events for the research pilot and are an important safety feature on all research missions.
Chase aircraft also are used as camera platforms for research missions that must be photographed or videotaped. Aeronautical engineers use this media to monitor and verify various aspects of research projects.
NASA