1) at normal level cruise- HS may have a slight leading edge elevation to provide tail lift- leverage to keep nose down. But during climb, leading edge of HS may be slightly lower than trailing edge to keep nose up.
2) At the time of leveling off, elevator trim changes from a few degrees nose up to nose down for level flight
3) At that time- something breaks, allowing HS to flip leading edge UP. Being uncontrolled, leading edge approaches vertical, putting tremendous loads on tal section aft of RPB, and virtually tearing off both HS fairly cleanly external to tail cone area.
IMO clues to the above are
1) both HS missing
2) said motion would put a major tensile load ( HS section just before separation ) on top half of fuselage and at the production join circumferential ahead of RPB and aft passenger exit door.
3) lower part would crumple in compression and eventually ( in a few seconds or less be torn off.
4) Plane absent HS makes rapid climb- and possible roll due to both HS not failing exactly as same time- thus damaging aft VS ( rudder )
At that point- the high g loads etc take over and tear off parts of fuselage, etc. - the rest is history
Summary- IMHO some sort of jackscrew, pin, clevis , or control failure of parts which normally keep the HS from flopping around was the instigator
One clue might be the condition of the RPB other than impact damage. IN my scenario, it is not a player. The tail cone would not rip off the bulhead simply because aft is not pressurised and skin stresses via rivets and bolts on the rim are much lower.
Comments ??
