On Mon, 06 Oct 2003 14:25:14 GMT, "Gord Beaman" )
wrote:

(WaltBJ) wrote:

The F104A would certainly exceed Mach 1 at zero feet. At Tyndall AFB
in the mid-fifties they did it about every day. All too soon the
authorities clamped down on it. FWIW with the old 3-b engine I've seen
725 on the clock at about 100'AGL.
Wonder what that Port St. Joe shrimp boat crew thought at 0600 when
they got a 'wake-up' call? Honestly, I was just burning out fuel prior
to landing and never saw thenm until too late.
Walt BJ

Of course Walt...who wouldn't believe that?...

It sounds believable to me. I did the same thing. Always had to burn
out fuel prior to landing. Always tried to do it most efficiently.
Jets burn more fuel at lower altitude, therefore burn down efficiency
improves lower. And, since the "horizon" at 100 feet isn't very far,
you could be upon the boat before you realized. Yeah, sounds right to
me.

Now, let's put to bed this idea of accelerating through the mach
straight up. While modern jets with greater than 1-to-1 T/W ratios can
accelerate through the vertical, I sincerely doubt the mach claim. Too
much is going on with drag curves, deteriorating performance with
altitude, losses in engine efficiency, etc. I think only heavy lift
rockets accelerate through the mach in near vertical, but they
transition out of vertical fairly early in the flight trajectory and
may not be vertical either.