wrote:

Henry J Cobb wrote:

Paul J. Adam wrote:

http://www.army-technology.com/projects/cl289/

gets you a jet-propelled UAV that's been in service for some time.

They're unusual - for most applications a prop seems to give better
endurance-range-speed tradeoffs - but not totally unheard of.

Props are more efficient at low speeds and low altitudes.

The Pentagon is still buying turboprop transports after all.

http://www.airforce-technology.com/projects/hercules/

-HJC

Perhaps, and if the Iranians or *other* future US Navy oponent wanted
to use UAVs soley for Transport/ Recon / and on call CAS then they will
probably be prop driven. However if speed, stealth and ability to
successfully strike US Naval forces is a design goal, then other forms
of propolsion are likely. Since many jets are built for civilian
markets and turbofans come in many sizes for smaller RC type aircraft,
it is certainly not unreasonable to expect to see them experimented
with by interested third parties.
PAIN
P.S. Before you try, I did not say either was a best option, only that
they are options, therefore muting the "prop makes big radar returns"
comment. Thank you, fly your Vulture selves elsewhere.


Jets have other possibilities, too.

I remember the first time I saw a stealth fighters. I was driving from
Las Cruces to Alamogordo on route 70. There is a very long straight
stretch and off in the distance I saw what appeared to be large birds
flying around. They did not move like any airplane I'd ever seen, but
where in a regular pattern. After a while I got closer and realized
they were jets doing touch-n-goes at Holloman.

One really interesting approach might be to make a UAV look like a bird
in flight. The, even if spotted, lookouts might not fully appreciate
what they are looking at.

John Mullen