Originally Posted by
43Inches
WRT the ATR,...
....however rollover events in service had continually be called pilot error, until Roselawn...
Icing can't be completely ruled out until the thrust and energy state of the aircraft can be reconciled. It appears unlikely. the roll appears to be a departure post stall. There is a suggestion of a slight pitch up prior to the wing drop. The CVR and DFDR will hopefully give answers as to the reason for the low energy state of the plane.
The video from the cabin, if it was faked, they went to extraordinary lengths. I don't believe that is likely, I fear that is the final moments of unfortunate pax and crew. The spectra of the audio comes out as below, the cell phone ?owner?'s voice is clearly traced, There is a line at 1760-1780Hz that would be interesting to pin down, it has a slight frequency drift, and I doubt that it is blower related, it isn't a simple harmonic of 50Hz or 400Hz. Would be interested in what gives that on an ATR72. If someone has the normal RPM range of the prop, that would be worthwhile. The engines are apparently winding down post accident, the spectra is clear on that, and those are more than likely to be the turbine running down. It isn't that often that a signature of an engine comes up after impact. The prop would have a reinforced 6th harmonic of the shaft rate, which is probably around what... 1100RPM, less than 20Hz shaft, 120Hz blade rate. Harmonics above that would then be at 12th, 18th.. and they don't seem to fit the wind down line, so that is going to be from the turbine. This would be likely classified as unsurvivable due to the attitude at impact, but the video/audio will give some insight into what can and what cannot be done to improve cabin safety. For flight crew, wings level at impact is an imperative, if possible by any means. This audio hints to that. I doubt that meaningful safety enhancement can be made to the cabin survivability for this type of event, but this video should be central to some serious consideration by the adults, if any remain in the building.
