On Fri, 24 Oct 2003 02:14:48 -0000, Jim Battista
wrote:

Mary Shafer wrote in
news
On Fri, 24 Oct 2003 00:01:56 +0200, "JasiekS"
wrote:

That's why they dump fuel
when exactly overhead, so you can see them. Well, and so you
can time how long it takes the boom to reach the surface, too,
except that you don't actually hear the boom from when it's
overhead but from when it's on down the flight track.

At Mach 3 cone half-angle of the shock wave should be approx.
19.5 deg. Let we assume 10k ft for the flight level. In such
circumstances I should hear boom when the aircraft would be 28k
ft away. Right?

Try 85,000 ft, not 10,000.

Honest newbie question: can you see much of anything with the unaided
eye, or non-fancy binoculars?

Sure. The plume of fuel that's being dumped and, maybe, a dark spot
at the head of the plume. On a clear day. If you're very keen-eyed.
Or imaginative.

Seriously, you could see the fuel plume and I think you could see the
aircraft planform in the LRO (Long-Range Optics) views, rather grainy
and fuzzy, or with very strong binoculars when it was close to the
facility, although I never tried with binoculars. There may well have
been a bit of seeing an SR-71 shape because we knew it was an SR-71,
too.

The fuel plume looks a bit like a loose contrail, by the way.

Mary

--
Mary Shafer Retired aerospace research engineer