barit1
The LP shaft by observation incurred no visible injury from the burst of the IPT. The HP shaft, nested withn the Drive Arm "Bell" is not seen. The third shaft of three, The Ishaft, terminates in a cylinder, the "Bell". Would you have any comment as to the vulnerability of this "Bell" to harmonic vibrations produced by the nested pair, and possible "whip" of this assembly, due wear of splines more forward of the IPT case? Considering the vibratory result can be multiplied through the length of the IP/HP shaft pair as it progresses aft, and in a super heated environment, would mechanical disruption play an important part in the burst (not to diminish the effects of "oil fire").
N speeds are not available at the time (per design) to effect a fuel cut. Instead, when N2/N1 values are rejected, the ECM recieives an NCD re: N3, and a value is providied that is 'theorized' by the Engine computer. (as I understand it). This allows the HP to soldier on, at least for six seconds?
regards