compressor stall,
The charts that you have indicated would appear to be better quality then the charts issued to the crew. One would have thought the Nav Dept would have been able to procure these charts, surely the US of A aircraft going down there would have had them. But the Lat and Long could still be established on the charts they were issued with, enough to show up the longtitude error between where they were and where they thought they were.
The map reading comment was a bit tongue in cheek.