The nose (section) broke off, and would fall immediately, The tail does not get "heavier" but the center of gravity of the remaining part of the fuselage moves dramatically, and instantly, aft causing the tail to drop and the wings to STALL almost immediately as the maximum angle of attack is rapidly exceeded.
That plane would not "Zoom Climb" for 15 seconds with no nose, it would be in a near horizontal Accelerated Stall after about 2 seconds and then drop like a stone.
You are claiming that somehow, a plane that had just blown into two pieces and had all it's engine and flying surface controls severed, was able to maintain stability to climb vertically for over 15 seconds before it pitched over and headed down.
A lightly loaded 747 can climb at about 6000 FPM, You are claiming that crippled, out of control, plane with no inherent stability can outperform that by a factor of 2
And finally, can you account for this eye witness testimony?
......Writes Dwight Brumley, a 20-year Navy vet who watched the tragedy unfold from above, after watching "Silenced":
"The CIA animation in no way represents what I saw that night. Based on the time line, as I understand it, the "flare" that I reported seeing off the right side of and below USAir 217 could not, I repeat, could not have been TWA 800 in crippled flight just before and after it exploded. There are two reasons why. First, TWA 800 would have been moving in my field of view from left to right, not from right to left as I clearly observed; and second, my understanding of the basic laws of aerodynamics leads me to conclude there is no way that TWA 800, with the nose section gone, could have possibly climbed 3,000-4,000 feet as the CIA video portrays."
Can't happen. You blow the front off that plane, and it loses the power control to the fuel pumps, and as much fuel as those engines need to run theres no way on Gods Green Earth they will keep pushing the plane up.