RJC the AAIB report doesn't mention ALT.A therefore (if it wasn't armed) the aircraft would not automatically level at MDA. The engaged modes are recorded on the FDR and I think the AAIB would have mentioned it if VS changed to ALT. But it would be ALT on the cyclic with manual intervention required to raised the collective to avoid even more rapid loss of IAS, so no practical difference in this case.