Hello,
I'm a student-engineer in embedded systems, my team and I are actually thinking about designing a UAV for a contest. The objective is simply to design a drone that incorporates innovative ideas that could increase the security or performance of civilian drones.
Our idea was to create an experimental uav that'd include an "autonomous safety systems" a box powered by arduino that would limit the altitude, trigger a parachute ( in case of an uncontrolled stall situation) and continously provide the position, altitude and speed of the uav, this safety package would allow any hobby airplane/light civil drone to respect the french legislation (parachute + automatic altitude restriction to 150m). Pixhawk/APM can offer those options but our option is really cheap and more importantly it is made by the team (we're in a contest), i use APM all the time in my multicopter :).
Except for the automatic altitude limitation, It should be compatible with APM2 (we don't own pixhawk modules so that's not planned) for gps autopilot osd etc.
The elaboration of the arduino code is quite advanced, but we're now brainstorming on ideas regarding the hobby/uav airframe itself, (we could go with a Hobbyking bix3 or a skywalker x8 but several other competitors are designing the uav themselves).
So I'd just like to know from one of the most experienced hobby/FPV/amateur UAV community what would make a electric airplane perfect for your hobby ?
Our UAV is aimed for civilians : FPV, fire detection, surveillance of agricultural areas or entertainment simply. So the scenario here is : Slow flight + Long Endurance.
One of my idea was to incorporate "modules" that would allow hobbyists to install an extra engine or an additional external battery very easily on the wing, just like army pods that allow the installation of an extra fuel tank or missiles 
. you would have in the pod an esc+brushless or a Li-Po, and on the nacelle the XT60/bullet plugs (and all the electronics/wiring behind of course). So one could change between an EDF engine, a prop engine or additional batteries quite easily.
We have cnc composite, 3D printing, laser plywood manufactories for the elaboration fo the prototype so that's not really a problem.
So please post your ideas, i've attached the first drawing of our prototype : I decided to go with straight-ish wing sweep + high aspect ratio for max endurance.
We'll go with EPO/Fiber glass/composite (depends on the lab capabilites) +balsa+ some carbon fiber for the first prototype.
Do you find our suggestions original/interesting ? I'm waiting for your suggestions.
(for instance : Blended wings or conventional aircraft design ?
How do you prefer to assemble the wings of your airplane : we have a system that takes 3-4 minutes is that too much (two big screws plus 2 smaller ones both requiring a screwdriver) ? ...)
I really like the blended wing design à la B2 spirit, and after reading some studies (boeing) on it, it is supposed to offer better performance for (relatively) high payload, long flight, but in the long term our goal would be to create a platform that would allow any student to test his experimentations on this airframe, using the same concept of easily fixable module pods/wings, hence the classic design.
the winglet is a nobrainer here for slow flights, especially if you read the small study directed by some researchers from the university of tokyo (http://www.ewea.org/ewec2006/allfiles2/703_Ewec2006fullpaper.pdf)
THANK YOU, and sorry if my english feels cheap, I'm French 
(we use 2D drawings, the factories accept DXF drawing for 3D printing or cnc)
(general drawing of prototype 0001)
PS : I really like airplanes, but my knowledge in aerodynamic is a little "limited", (I'm in embedded systems/computer science/automatisation), but i understand the basics of fluids mechanic and aerodynamic.
PS2 : we're not planning on selling it at all btw, it's aimed at research and experimentations.
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