Following the first 50 hour oil change after a recent overhaul, the engineer who completed the overhaul and service, arranged for he and his wife to accompany the pilot on a scenic flight of the local area. The flight was conducted at an altitude of about 400 feet above ground level and proceeded normally for about 15 minutes until the engine suddenly lost power, it then ran roughly momentarily, before stopping. The pilot attempted to land the aircraft in the only available area, a confined swampy area, but during the approach it struck a large tree and crashed into the swamp. The inspection and testing of various components of helicopter was hampered by the aircraft having been submerged in the swamp, and no reason for the apparent loss of power could be determined.
