But I'm going to try anyway.
When an airplane is in level flight, the forces working on it are in a certain equilibrium. The lift (which comes mostly from the wings) is equal to the weight. The thrust (which comes from the powerplant[s]) is equal to the drag (which comes from several different sources).
In conventional monoplanes (which includes everything from a Cessna 172 to the 747-400 and beyond) the wing provides a center of lift which is slightly aft of the center of gravity. This ensures that the center of pressure is aft of the center of gravity (necessary for stability). What that means, is that if these planes did not have a horizontal tail, they would nose down in normal flight.
Well, we know that planes don't always nose down uncontrollably in normal flight. Why not? The horizontal tail, either because of its position, its inverted airfoil (vis-a-vis a wing), or its negative incidence, or some combination of these design features, provides a nose-up push -- what we who grasp these things call a "pitching moment" -- that counteracts the wing's tendency to pitch the plane nose-down around the center of gravity.
What happens, if as happened to 800, when a catastrophic event, an explosion, causes a lot of the structure to shear off of the nose of the plane? These things:
Nothing here is beyond middle school science. Unfortunately science makes few inroads on minds that are slaves to irrational belief systems. A conspiracy theory is attractive to such minds, because it ties up all the loose ends (if the evidence doesn't fit the theory, you selectively discard and manufacture evidence to fit -- the 800-missile crew perfectly illustrates this).
Then again, 800 wasn't straight and level in the first place. It was climbing anyway, so its energy vector was above the horizontal to begin with.
You apparently think that pieces of an airplane demolished by an explosion, a midair, or a weather encounter, instantly shed all the energy they contain and fall straight down. Nope. That is a child's understanding of objects in motion, and a rather dim child at that.
Sigh. I don't know what I hope to achieve. We live in a nation where most people believe that the Air Force has aliens in the freezer and nuclear reactors are the same thing as nuclear weapons. If there is a reason to hate the government, it's the crappy education that leaves people vulnerable to such eruptions of folly.
d.o.l.
Criminal Number 18F (Time to check the temp on E.T.)...
PS you can test this yourself on one of those styrofoam 747s they sell in toy stores -- you know, the big glider. Trim it so it flies straight when you throw it. OK, now take a knife and cut it off bluntly in front of the wing. Without altering the trim, throw it. It tries to loop up and stalls.... a real 747 would be stressed enough to continue breaking up. -C18F