TC, I am very much in agreement with you. Although I do agree with others that the 400' radar return came during the final descent.
I also see [TC, JEacott agree] no reason to conclude that he did not enter auto. On the contrary, intermittent low Nr warnings followed by later steady low Nr would indicate to me that he did.
My take:
A simple mistake during a XFER PUMP changeover and they are both off. Difficult to see panel (night, perhaps NVG) and no immediate visual indication that a pump was left off.
During the actions following RED indications, the PRIME's are turned on vice XFER's. (it is my understanding from all the reading I have done, that there is no caption for XFER PUMP in an off pos'n).
As for the landing: unless autorotations to touchdown are practiced regularly at night, it is very difficult to get it right. The normal reaction is flare too high. NVG's provide better visuals but in my day on them the depth perception was poor.
A very similar incident happened to a 212 in the Maldives. With no rad alt the flare was high, and the high G impact that followed was not survivable. Even high inertia blades stop quickly in an overpitch.
2 things that are often overlooked when considering how fast Nr will decay in such a scenario:
1. The engines are NOT at idle contributing residual thrust. This is significant in distorting the true Nr behaviour in a turbine a/c performing Autos.
2. Adding pitch to a rotor on the ground to slow it more quickly following a shut down (bad practice) is not the same as low Nr in flight. AoA is hugely different.
Finally, is it really considered plausible that an airframe could fall 1000' perfectly level, or that a tumbling a/c would land upright by chance?
Occam's razor.
Last edited by pilot and apprentice; 16th Feb 2014 at 17:14.
Reason: edited to add: we all make mistakes. He did, I have, we all will. Hopefully we learn from them