This was the first flight by a newly hired pilot, who had qualified as captain on the previous flight and occupying the left (Captain) seat as PF. A highly experienced (41,000 hrs) check Captain was in the RHS. The Flight Engineer had also been with the company for only 4 months. No CVR trace was available so the report is lacking in some significant details. 

The crew anticipated, briefed, and later received a clearance to conduct a localizer (LOC) approach to Runway 30. At that time the destination weather was reported as VMC and it was expected that the runway would be in sight prior to the final approach fix (FAF).

On final approach the crew were advised that the visibility was one mile in snow showers. The crew had miss-set the MDA altitude bugs and 4 minutes later flew through the MDA, triggering a GPWS alert. The crew made a go-around rather than a full GPWS escape procedure,and the aircraft struck trees, reaching a minimum altitude 30 feet below airfield level, 2.7 miles from the runway.   

After changing frequency the crew were passed a METAR of 6 miles and decided to return for a second approach, but again found that the visibility given on final was only 2 to 3 miles. The aircraft landed successfully from this approach.  

The report analysed multiple factors leading to the event, including the use of the step-down "dive and drive" procedure. It noted that the company subsequently changed its policy regarding crew co-ordination procedures: "The requirement for PMA procedures to be used on non-precision approaches has been raised (from 300 feet and 1 statute mile) to weather minima of 1000-foot ceilings and 3-mile visibility".   It did not however make it the default procedure which would have recognised the inherent unreliability of weather information passed to crew by ATC as an indicator of the conditions that would actually be encountered.