Unmanned Aircraft Systems Roadmap 2005-2030 - Federation of ...

UAS ROADMAP 2005
Gasoline Engines
Fuel Density * Fuel Volume
+ Engine Wgt/HP *HPreq
+ Accessories Wgt
Total Wgt
Specific Energy = HP*hr/Total Wgt
Battery Propulsion
Electrolyte Wgt
+ Cathode & Anode Wgt
+ Case Wgt
+ Power Conditioning & Wiring Wgt
+ Motor Wgt
Total Wgt
Specific Energy = W*hr/Total Wgt
APPENDIX D – TECHNOLOGIES
Page D-6
Fuel Cell Propulsion
Fuel Density * Fuel Volume
+ Fuel Cell Wgt
+ Reformer System Wgt
+ Power Conditioning & Wiring Wgt
+ Motor Wgt
Total Wgt
Specific Energy = W*hr/Total Wgt
FIGURE D-4. SPECIFIC ENERGY CALCULATION.
Propulsion - Hovering
The ability to take-off and land vertically can provide added operational benefits, such as being able to
operate from a forward arming and refueling point with manned assets or from other unimproved areas.
DARPA currently has several joint programs with the Army developing vertical take-off and landing UA.
These include the small OAV and MAV ACTD, which are pursuing ducted fan aircraft with the ability to
hover and fly in forward flight efficiently, as well as the much larger A160 advanced unmanned
helicopter program. Other aircraft, such as the RQ-8 Fire Scout are also being developed for a VTOL
capable UA. A goal of the small UA DARPA programs is to field aircraft with the ability to "Perch and
Stare.” Conceptually, this would enable the UA to land in a place that it can observe the scene where
enemy activity is of interest. The purpose of this capability would be for the small UA to observe
movement (change detection) and notify the human user by sending a picture of the object that has moved
(changed). This reduces the fuel required to operate and increases the time on station significantly and
eliminates the users need to "watch" the video screen. This concept does not need to send pictures unless
requested or movement is detected, which would further reduce power consumption and increase
endurance.
Aircraft Structures
Mission, environment and intended aircraft performance attributes are key drivers for UA structures in the
same sense as for manned aircraft. At one end of the “UA spectrum” aircraft such as the Finder and
Dragon Eye diminish the need for durable structures. This is contrasted with Global Hawk class UA
where individual airframes are planned to be in the Service force structure for periods comparable to
traditional manned systems.
Similarly, environmental requirements drive interest in aircraft structures in three basic directions. UA
primarily intended for tactical use in the close vicinity of ground forces dedicated to force-protection
missions will have modest requirements for systems redundancy. For UA intending to be certified to fly
in civil airspace, the recognition of redundancy requirements is a factor for the development of systems
and integration for the entire aircraft. This tends to drive up the scale of the aircraft and the structures
needed to host capabilities and multiple systems needed to support larger scale performance for
endurance, altitude and extended reliability. The need for a capability to operate and survive in highthreat
areas adds the need for signature control, which becomes a consideration for structures planning.
� Wing. Keeping targets of intelligence interest under constant and persistence surveillance is
increasingly valued by operational commanders. This, in turn, drives interest in wing designs that can
bring the greatest possible measure of endurance to collection platforms. Technologies being
investigated to increase wing performance include airfoil-shape change for multipoint optimization,
and active aero elastic wing deformation control for aerodynamic efficiency and to manage structural
loads. Research needs to be expanded in the area of Small Reynolds Number to improve the stability
of small UA. This is especially true for the mini- and micro-UA classes using high aspect ratio
wings. These platforms suffer lateral stability problems in even lightly turbulent air, which induces
sensor exploitation problems and exacerbates the task of the aircraft/sensor operator. Research and
development work with membrane wing structures appears to offer a passive mechanism to reduce