From: Michael S. Lorrey (retroman@together.net)
Date: Tue Feb 16 1999 - 07:30:44 MST
Ian Goddard wrote:At 10:51 PM 2/15/99 -0500, Michael Lorrey wrote:
>
> >Not necessarily. A plane can be stalled and still be moving forward at high
> >velocity. It is the angle of attack which matters when it comes to lift, not
> >speed. Once it blew in half, the front section was front heavy and acted
> like a
> >lawn dart, translating its forward speed into downward speed.Calculate in its
> >forward velocity (probably around 300-400 mph) while climbing, being
> translated
> >over by the change in angle of attack to downward velocity....
>
> IAN: Horizontal velocity is independent of
> vertical velocity, what that means is that
> you don't translate forward velocity into
> downward velocity. Basic kinematics, but
> again, not a factor in the CIA scenario.
Absolutely wrong. What do you think a wing does? Any airfoil or hydrofoil shape is
useful because it translates foward motion to upward accelleration when oriented
to the proper angle of attack to generate lift. This is why it shot upward so fast
when it lost its nose, and why the nose started dropping so quickly. The angles of
attack of the two parts generated lift (upward for the rear section, and downward
for the nose section) which caused added acceleration in their respective
direactions, translating forward momentum into vertical acceleration.
The reason why the peices only had a 400 mph velocity when they hit the ocean is
because of what is called 'terminal velocity'. This is when the forces of
acceleration (in this case gravity) are exactly counterbalanced by the forces of
aerodynamic drag, thus preventing any additional speed gains. The human body has a
terminal velocity when sky diving of around 125 mph in a prone position, and over
200 mph in a dive. Now, at 400 mph, assuming that aerodynamic forces cause a pitch
over and momentum translation in 5 seconds (not unheard of and similar to a 6g
turn in a fighter plane, which, considering the new angle of attack the nose
seciton had to its forward velocity, is likely, then the nose section would have
dropped 6.6 miles in one minute traveling at a terminal velocity of 400 mph (which
is about 3 miles in 24 seconds). The CIA simulation probably refers to the nose
section hitting the ocean, although it is not totally inconsistent if dropped from
17000 feet.
Dropping from 17000 feet from a total stall you have:
S=(32ft/s)*(29^2)/2=13,456 feet.
This almost exactly matches the nose section trajectory. The additional 350 feet
of altitude would have been bridged due to velocity translation by airfoil effects
being added to the acceleration profile. So the nose section hit the ocean at 29
seconds.
I suggest that you seek out a written timeline from the CIA of this analysis. I
think you will find that what I say is true and that the rear section hit a little
later.
Mike Lorrey
This archive was generated by hypermail 2.1.5 : Fri Nov 01 2002 - 15:03:04 MST