AFRL Completes Automated Aerial Refueling Station-Keeping Flight Test
By Plans and Programs Directorate, AFRL/XP
/ Published December 12, 2006
WRIGHT-PATTERSON AIR FORCE BASE, Ohio -- AFRL researchers completed a series of automated aerial refueling (AAR) station-keeping flight tests. The test series included the first autonomous flight of an aircraft in the refueling position behind a KC-135 tanker.
The purpose of the AAR program is to develop and demonstrate operationally representative subsystems enabling the existing Air Force tanker fleet to perform boom and receptacle refueling of unmanned air vehicle (UAV) systems. Expected benefits of AAR to UAV operations include increased combat radius, extended mission time, reduced response time for time-critical targets, reduced need for forward staging areas, and increased in-theater presence. The station-keeping flight test integrated components on the tanker and receiver aircraft to demonstrate the receiver aircraft's capacity to autonomously hold a position relative to the tanker throughout the tanker's execution of standard refueling maneuvers.
During the flight tests, a pilot manually flew a Learjet acting as a UAV surrogate to the contact position behind a KC-135R. Once the aircraft achieved a position at which it could receive fuel from the tanker, the Learjet's AAR flight control system was engaged, which enabled the aircraft to autonomously hold the contact position while the tanker executed both straight and level flight and turns. The AAR system remained engaged at the contact position for 23 consecutive minutes, allowing the Learjet to follow the KC-135 through two full orbits.
Over the next year, the AAR team will build upon the success of the station-keeping flight tests to facilitate new automated refueling capabilities. For example, the team will demonstrate autonomous maneuvering around the tanker, wherein the Learjet's AAR system will first engage at the observation position on the tanker wing and subsequently be directed from a control station to go to the precontact and contact positions upon approval from the tanker crew. This future test will employ simulations combining multiship operations around the tanker and long-distance tanker rendezvous to demonstrate the AAR system's readiness for transition from the Learjet test bed to AF assets.