Pilot error may be the initial blame... but at the core of this is MANAGEMENT ERROR!!
Both of the latest two incidents can be put down to the Management group of PX. I can assure you the pilots of the Dash 8 in Mendi only went there once Op’s (their management) gave them the clearance to fly there. PX would often delay/cancel flights to areas of civil unrest and it was only once management had given the thumbs up to return would the pilots go, once the management decided the risk was at a manageable level. Except on this instance they got it wrong.
As for the pilots of PXE in Chuuk. Yes they were sitting up the front last Friday. But ever since the PX Management decided to restructure the pilot conditions in 2014, a huge amount of experience within their pilots ranks left PX for better jobs.
The number of resignations since 1st January 2015 has clicked over 50% of the pilot group at that time. Imagine QF, VA, CX, BA loosing half of their pilots in such a short time frame.
In the environment that PX operates, this is a huge hit.
Some have forecasted an accident like this occurring.