Following a signal from the cabin attendant that all was ready for take-off, the pilot applied power and lifted the helicopter Into hover. After a momentary check of power and trim the pilot began to move the aircraft forward along the line of the taxlway towards the runway. At a height of less than 10 feet and with a forward speed of some 5 knots the aircraft engine coughed and lost power. The pilot noticed a drop and fluctuation In engine fuel pressure and the fuel booster pump low pressure warning light Illuminated. He reduced power and landed and as the aircraft touched and rolled forward, ground resonance commenced. The pilot endeavoured to lift the helicopter back Into the air In order to terminate the ground resonance, but this was- unsuccessful owing to the lack of engine power. The severe rocking motion, as ground resonance developed, bounced the aircraft to the left and the pilot then applied the rotor brake. The main rotor blades struck the ground, the undercarriage failed and the helicopter came to rest having rotated more than 180 degrees from Its original heading. The pilot carried out an engine shut down check and he vacated the aircraft through the right hand cockpit window. All the other occupants vacated the aircraft through the main cabin door under the direction of the cabin attendant. Fuel was seen to be pouring from the lower forward section of the fuselage and this Ignited whilst the passengers were still evacuating the cabin, forcing the last persons out to leap through the flames.