Reguardless of the detractions of some folks, there is an internation drawing standard that is recognized and contrary to the comments found here the ASME/ANSI standards are very useful. It is not necessary to follow the thread of the many reference documents to derive the major benefit from...
What sort of loiter time are you looking for? The problems with such high altitude projects is removing heat from the propulsion system, using the low density air found at that altitude. There is one such successful high altitude project that uses solar cells, batteries and electirc motors to...
The following UR's cover the present manufacturers of complete ducted fan units:
Internal Combustion (IC) Engine Driven Ducted Fans
<http://www.tgajets.com/accessory/Byrofan.htm>
<http://www.trimair.com.au/ramtec.html>
Electric Motor Driven Ducted Fans (EDF's)
<http://www.wemotec.com/>
I...
