The briefing for the approach was not complete, based on an assumption of relatively non-challenging conditions for a crew who were returning to their home base. These did not correspond to what was actually encountered.  

The Captain was acting as PM but the F/O as PF seemed to defer some PF tactical decisions to him. As the weather was deteriorating the Captain was involved in some extraneous communications, and as a result the two pilots lost any common plan as to which autopilot modes would be used for the approach.   

The final approach was then started early, and the crew did not respond to an automated "minimum" call. Both appeared to be seeking external references as the aircraft passed below MDA, and a go-around was eventually called by the Captain in response to a GPWS "Terrain" alert. Neither pilot responded properly to the unexpected go-around with confusion as to what modes were in use, amongst other things, prior to the loss of control and the aircraft crashing. Somotogravic illusions probably played a significant part in this.   

It is unclear whether in this case it was a "F/O" (PicUS) sector, or whether the operator applied different criteria for F/O landings. On the assumption that the Captain would have been "in charge", a PicMA SOP might have impacted a number of aspects.

• There would have been a clearer understanding of which pilot had responsibility for what aspects, following a more comprehensive and interactive briefing.  
• The approach might have been better monitored by the Captain. The same crew had miss-flown the same approach with a go-around only two weeks earlier. 
• As the aircraft approached the MDA, the First Officer would have been fully prepared for a Go-Around if necessary. As it was both pilots were clearly startled by the GPWS alert, and the F/O was unsure as to whether to go around. The Captain did not respond appropriately once the go-around had been initiated. 
• Only the Captain would have been seeking visual reference. As it was the F/O transitioned from instruments to seeking visual cues prior to returning to instruments for the go-around, increasing his vulnerablility to somotogravic illusions which were possibly a significant contributor to loss of situational awareness and subsequently loss of control.