On October 24, 2007, about 1400 Pacific standard time, a Robinson R22 Beta, N7188S landed hard on Pad 4 at Long Beach Airport, Long Beach, California. Los Angeles Helicopter operated the helicopter under the provisions of 14 CFR Part 91. The certified flight instructor (CFI) and the student pilot were not injured. The helicopter was substantially damaged. Visual meteorological conditions prevailed, and no flight plan had been filed. The local instructional flight departed Long Beach Airport about 1300. In the Pilot-Operator Aircraft Accident Report, the CFI stated they were practicing low rpm recoveries at Pad 4. He instructed his student to execute the recovery when the low rpm warning system activates: light and horn. Prior to the maneuver, the CFI demonstrated and verified that the student pilot understood the recovery procedure: to lower the collective and increase the throttle. The CFI stated that the helicopter was in a 10-foot hover when he decreased the rotor rpm by reducing the throttle until the low rpm warning system activated. The student pilot responded by lowering the collective and reducing the throttle instead of increasing the throttle. The helicopter yawed to the left and descended towards the ground. The tail rotor collided with the ground, shearing off the tail rotor blades and the helicopter rotated on the ground. The CFI slowed the rotation and was able to shut down the helicopter. The CFI reported the helicopter and engine had no mechanical failures or malfunctions during the flight. According to the Robinson R22 Flight Training Guide, the recovery for low rotor rpm at a hover is to "lower the collective and simultaneously adding throttle. If the rpm cannot be regained prior to ground contact, insure that the helicopter touches down in a level attitude."