## 3 Fields of Innovation in UAS  
The table of contents of major aerospace conferences shows many UAS related papers. Of these papers many are platform oriented, based on the premise that UAS provide a less constrained solution space than manned aircraft. Yet, UAS platforms are consolidating in Groups 1 to 4 with very few basic planforms and minimal exotic aeronautics. Groups 2 to 4 UAS are simple aerodynamically compared to manned aircraft, as they are not fast, agile or large, or aggressively optimised for a well understood role (such as an airliner). There is no apparent drive to change this. The exceptions to this are Boeing/Insitu's ScanEagle [28] and Integrator/RQ-21A Blackjack [38], which won STUAS/Tier II competition [39] and Northrop Grumman Killer Bee/Bat [30]. ScanEagle, Bat and Integrator are unusual air frames, with unusual launch and recovery mechanisms. Only in the UCAV, XA and Group 1 and below are significant platform innovations visible or perhaps tolerated by stakeholders.  
Many fielded UAS have clear road maps to 2020 and beyond [2], and new platforms are less favoured than upgrades to existing ones. Breakthroughs in research on air frame or propulsion design in Groups 2 to 4 UAS do not appear to be immanent.  
With the exception of quadrotor aircraft, Group 1 show minimal platform innovation, indeed many Group 1 UAS trace their conceptual design to the late 1980s rudder steered glider, the Aerovironment Pointer [40].  
It is illustrative to list a mixture of manned aircraft and unmanned aircraft, the innovation found in their design or system and the era in which the work was done, shown in Table 1.  
Relative lack of innovation opportunity in UAS in Groups 1 to 4 is quite striking. UAS innovation is tending to occur in their _operational application_ rather than their design. Operations then drive subsystem technologies to provide the required capability. To clarify the logic of what is transpiring: the golden age of innovation in air vehicles occurred in the 1940s to the 1960s; UAS are air vehicles, so it is unlikely that dramatic revolutions in air vehicle design will occur at intermediate scales.  
\begin{table}
\begin{tabular}{l l l} \hline \hline
**Aircraft** & **Innovation** & **Era** \\ \hline U-2 & Altitude, High Aspect Ratio Jet & 1955 \\ SR-71/D-21 & Manned/Unmanned Team, Speed, Gigh End UAS & 1960 \\ Harrier & VTOL & 1965 \\ F-111 & Variable Geometry, Escape Capsule, Turbofan, Terrain Following & 1965 \\ [PERSON] _et al._ & UAS, _cf._ D-21 & 1965 \\ F-16 & Fly by wire, Relaxed Stability & 1970 \\ Pioneer _et al._ & First Tactical UAS & 1980 \\ F-117 & Stealth, Instability & 1980 \\ Pointer & Hand launch UAS, Deep Stall Recovery & 1986 \\ F-22 & Thrust vectoring, Aerodynamic Stealth, High Supercruise & 1990 \\ Global Hawk & _cf._ U-2, D-21 & 1995 \\ Scan Eagle & Sky Hook & 2002 \\ Quadrotor & Mechanically Simple VTOL & _ca._ 2000 \\ \hline \hline \end{tabular}
\end{table}
Table 1: List of aircraft, the innovation with which they were equipped, and the approximate era.  
Operational success may have even stifled various elements of innovation as major UAS such as MQ-9 are still being procured and upgraded [41].  
There is no lack of innovative thought in air vehicle science. It appears that the cost, risk or specialization associated with innovation is not justified in the current Defense UAS market. To date the strength of fielded UAS designs above Group 1 has been in their ability to be adapted to new roles, indicating a beneficial lack of specialization and thus lack of support for specific optimization.