On October 7, 1994, at approximately 1545 hours Pacific daylight time (PDT), a Robinson R-22B helicopter, N8072V, registered to Puget Sound Helicopters, Inc., operated by Puget Sound Flight Center, and being flown by Ono Makato, a recently certificated private pilot, was destroyed when the tail boom/rotor assembly struck terrain while maneuvering close to the ground. The pilot received minor injuries. Visual meteorological conditions existed at the time and a company flight plan was in effect. The flight, which was an instructional solo, was to have been operated in accordance with the requirements set forth in 14CFR91, and departed Everett, Washington, at approximately 1430 hours. The pilot, who had just received his private airplane single engine land certification and was in training for his rotorcraft rating, reported having a total of 59 hours flight time in the R- 22 out of a total of 139 hours. The pilot reported that he had arrived in a wetlands area to practice "quick stop" maneuvers at approximately 1540 hours. He then accelerated from a hover, turned to avoid an obstacle, and initiated his first quick stop maneuver by "lowering collective and using aft cyclic (flare)." The pilot stated that "when the helicopter started to sink I heard a noise, possibly coming from striking the tail on the ground." The helicopter then began a clockwise rotation, settled into the water and rolled over. The pilot recommended that he "fly the maneuver at (a) higher altitude to avoid striking the tail on the ground" as corrective action.