There were two presentations on the Swift ultralight flying wing at this year’s Electric Aircraft Symposium. Dr Steve Morris of the MLB Company related the flight testing of a manned version of the craft, which had been and is being modified by a group of NASA researchers.
That NASA team presented material on the unmanned version of the Swift, as modified to allow autonomous flight. Three industrious and inventive souls, Corey Ipollito, Paul Espinosa, and Al Weston, presented their work on the Swift Unmanned Aerial System (UAS), which they are undertaking with a small team of experts as a mostly volunteer effort at NASA Ames Research Center at Moffett Field, California. Ilan Kroo’s famous design has had many variants, including several others electrically powered, but none quite as sophisticated, and none with the range of missions envisioned for the craft by this trio. The airplane, test flown in December 2009 by Brian Porter for MLB, carried its human payload for a total of 20 minutes on its first day of flight (“A Manned Swift Takes Flight,” March 5, 2010).
Because the Swift has good performance as a powered craft and as an ultralight sailplane, the team’s objective of creating an autonomous vehicle had sufficient payload to enable carrying radio controlled or autonomous flight systems and various mission-based hardware. Without a pilot to carry, different weighty packages could be used by clients such as the U. S. Geological Survey (U. S. G. S.) for earth sciences, or by crime scene investigators for aerial surveillance of cold case crime scenes – only a small sampling of the capabilities available. This application range fits well with MLB’s primarily domestic applications, including convoy following, agricultural mapping, homeland security reconnaissance, and mapping of traffic or power-line corridors.
The team used government-supplied off-the-shelf and commercially available off-the shelf (GOTS and COTS) equipment in modifying the craft. Controls are split into four segments on each semi-span of the aft part of the wing, each actuated by its own linear control unit. This allows testing of the actuators themselves, easy replacement by new units requiring assessment, and great flexibility in the aircraft’s control. Not only the control system, but the power, avionics and payload systems can be networked and monitored. The general “health” of the craft can be monitored, with structural feedback, advanced sensing materials, and sensor webs that enable full data acquisition from the various systems and subsystems.
Flight and navigation systems particularly, but all systems generally have three or four levels of redundancy to comply with Federal Aviation Administration (FAA) requirements for autonomous flight. Being based at Moffett Field has the advantage of providing relatively clear airspace between San Jose’s and San Francisco’s major airports for close-to-home flight testing.
Combining a well-proven airframe with creative ideas and novel systems allows verification of system readiness at a mid-point between computer simulations and flight testing of larger, more expensive machines. The low cost of the basic platform achieves remarkable feedback for a relatively small investment.