High Altitude Short Endurance in this case: A couple of weeks ago a friend of mine told me about a RC-pilot-hero he knows and who had told him about his idea to make a model climb to seven kilometers of altitude (don't why particularly 7 km). We discussed the question whether a glider like configuration similar to DFS-228, Lockheed U-2 or Grob Strato 2C would be necessary to achieve this. For sure, this is the right approach if the aircraft is intended to stay so high for a while. If not, something like a high altitude research rocket might be better instead. Not wanting to deal with hazardous rocket propellants, a big coaxial propeller might pull a streamlined fuselage into the sky. The result reminds a bit of Convair Pogo Stick and Lockheed XFV-1. comparing the capacity of a Li-Ion-battery with the energy necessary to lift only its weight by 7000 m , there are some doubts whether this could work with purely electric propulsion. Additionally, you need something to detect altitude as well as climb rate at least to be able to say "We've been there!" Besides a GPS-antenna I decided for a long hose tube hanging down from the tail carrying a static pressure probe, far away enough from the body's displacement. A pitot tube in the nose will detect the total pressure prior to the props' influence in order to obtain vertical velocity. Rotor blades are stretched version of the tricopters' ones, stabilizer airfoil as well as shape of the body is a modified NACA 0012. At last, the easiest way to reach very high altitudes seems to be a balloon, as already Auguste Picard proved. While dynamic pressure scales with the speed to the square as wing surface does with lengths, displacement rises with the diameter to the third; all three linearly compensate for density. AutoCAD 2011 Panasonic FZ-20 (23 august 2006) Corel Photopaint 7 Notepad