The Cessna Caravan N208EC was based in Weston Aerodrome outside Dublin. The airplane was requested by the Clifden Airport Committee for a trial flight. The purpose of the flight was a demonstration of an aircraft to a group of potential investors and interested parties associated with a proposed airport at Clifden, Co. Galway, some 25 nm to the northwest of Connemara. The pilot flew to Connemara-Inverin in the morning together with an Aircraft Maintenance Specialist and conducted a familiarisation flight to Inishmaan (Inis Me in). The group assembled at Connemara, but as there were too many passengers to be accommodated on one aircraft, two flights were proposed with the aircraft returning to pick up the remainder. The aircraft then departed with the first part of the group. On arrival at Inishmaan, the pilot contacted those remaining and informed them that he would not be returning for them because he was uncomfortable with the weather. This did not cause a problem because an Aer Arran Islander aircraft, with its pilot, was available to fly the remainder of the group across to Inishmaan. Following lunch and a presentation the group returned to Connemara. N208EC took off with eight passengers on board. There had been a significant wind shift, since the time the aircraft had departed earlier from Connemara that morning, of which the pilot appeared to be unaware. As a result a landing was attempted downwind on runway 05. At a late stage, a go-around was initiated, at a very low speed and high power setting. The aircraft turned to the left, did not gain altitude and maintained a horizontal trajectory. It hit a mound, left wing first and cartwheeled. The pilot and one of the passengers were fatally injured. The remaining seven passengers were seriously injured. The aircraft was destroyed but there was no fire. CAUSE: “The Pilot attempted to land downwind in marginal weather conditions. This resulted in a late go-around during which control was lost due to inadequate airspeed.” CONTRIBUTORY FACTORS: 1. Communications were not established between the Pilot and EICA thus denying the Pilot the opportunity of being informed of the changed wind conditions and the runway in use. 2. The aircraft was over maximum landing weight. 3. The altimeters were under-reading due to incorrect QNH settings. 4. The additional stress on the Pilot associated with the conduct of a demonstration flight.