The investigation concluded that, based on conversation on the cockpit voice recorder, the descent was intended to be performed at a flight path angle of 3.3 degrees. However, the investigators noted that the actual commanded descent was 3,300 feet per minute, and may have been the result of having inadvertently selected the vertical speed mode on the autopilot control panel. In this case, minus 33 would have appeared on the autopilot display, implying a 3,300 foot per minute descent, while in the flight path angle mode, minus 3.3 would have appeared in the same window.
That is the anti Airbus brigade theory! We don't CFIT due to high vertical speed but descending under the bottom of the approach !
Flying at 220 Kts a 15% slope requests 3300 Ft/minute, as we pilots all know (220 x 15 = 3300)
The crew was not aware that , descending step by step the VOR-DME approach and not the derogatory CDA, altitude 3660 FT was mandatory at 7 NM to STR VOR as "FAF" was not indicated.
The crew respected "don't descend 4300 FT before 9 NM to STR due to possible false GPWS warning", and the next mandatory step seemed to be 1340 FT passing STR , without the three magic letters "FAF". Descending the 15% slope from 4300 FT to 1340 FT they met the ground.
Sorry for off topics.