On Oct 30, 11:08 am, Bertie the Bunyip wrote:
"Gig 601XL Builder" wrDOTgiaconaATsuddenlink.net wrote :

Gatt wrote:
"Morgans" wrote in message
...

What he is hinting at is probably the Aurora. You know, the one that
leaves donut shaped con trails?

That's no longer with us, is it?

Well according to THE GOVERNMENT it never was. And the plane that
didn't/doesn't exist was supposed to be pulse jet.

Not quite. Though the principle is essentially the same, the engine has not
moving valve at the front. A pulse jet wouldn't be able for supersonic, let
alone hypersonic flight.
the inlet would have an annular inlet arranged so the flow would direct
each pulse down the rear of the engine, but there would be a small efflux
out of the annular inlet. The biggest advantage to this system is that it's
easily throttleable simply by varying the frequency of the pulses.
this thing almost certainly exists. More than likely it's a development of
the Convair Kingfish which was , like the A-12, an upshot of project GUSTO,
but we're not going to be told anytime soon! I read about the Kingfish
years ago and can't find anything decent about it on the net, but it was a
parasite aircraft with some sort of ramjet or zip engine that had a ceramic
coating and was capable of cruising at over mach 4. At least one of it's
designers has alluded to it actually having gone ahead, but it's still a
very black item.

Bertie

I think it's pretty likely that Kingfish (or Aurora or whatever they
actually called it) is flying. If I had to guess, I would say they
retired the SR-71 because it was old technology and because it was
vulnerable to newer generation anti-aircraft missiles. As far as the
secrecy surrounding the new aircraft, it is hard to see what would be
gained by making it public.

Phil