At FIRE warning, the chronometer was halted, then restarted after the warning reverted to OverHeat. This is the testimony of SCC Evans.
This event has caused an immediate change to the DEP such that the EEC will shut down an engine of this type prior to certificated delay times. Had the Fuel been pulled earlier than 2:01:11, this Burst may not have happened. What remains is to determine if overspeed even occurred?
If the IT slid back to contact the stationery Stator ring, it surely slowed, and heated up. Had it slipped further, the Blades would have sheared off on the Stator Vanes Platform. Loss of blades drops the N2 to zero, and the N1 as well, as the LPT has nothing in front of it by way of gas. By this time the contact area of the Drive Arm and Stator Ring are fluid, and the Drive Arm gives up completely, the Disc wobbles and disintegrates. The first Bang, was it Stall? Was it caused by IPLP cavity Pressure releasing forward through the bladeless aperture at the IPT Rim? A forward exit of all Gas Path contents that upset all mechanical stresses? The second Bang the Rupture of the Case?? Someone with Turbine sense could look at the reads and the evidence??
Last edited by bearfoil; 27th December 2010 at 14:00.