19990714009029A

(Tty) Houston police department public use acft (1975 Hughes 269C helicopter) was involved in night training when the acft landed hard, the main rotor blades cut off the tail boom, and the left rear strut collapsed. (.19) on July 14, 1999, at 2151 central daylight time, a Hughes 269C helicopter, N7491F, was substantially damaged during a hard landing while maneuvering at the Houston Hobby airport, near Houston, Texas. The flight instructor was not injured and the commercial pilot receiving instruction sustained minor injuries. The helicopter was owned and operated by the Houston police department. Visual meteorological conditions prevailed for the title 14 CFR part 91 instructional flight for which a company flight plan was filed. The flight originated from the Houston Hobby airport about 30 minutes prior to the accident. According to personnel at the airport, the helicopter was conducting night training operations as part of the night check out for the pilot receiving instruction. The helicopter had been cleared to maneuver out of ground effect over the grassy area between taxiway golf and runway 17, on the west side of the airport. The operator reported that the helicopter landed hard, and the main rotor blades came in contact with the aft fuselage, severing the tailboom. The right rear landing strut collapsed; however, the helicopter remained in the upright position. (.4)during a night instructional flight, the helicopter landed hard during a practice autorotation following a simulated engine failure during takeoff. The operator stated that the toe of the right landing gear skid sank into the ground, and the helicopter made a 90 degree turn. The main rotor blades made contact with and severed the tailboom of the helicopter. The operator reported that the maneuver was entered below the recommended airspeed of 60 knots, and consequently a high rate of sink developed during the landing flare, which the pilot receiving instruction was unable to arrest. No mechanical malfunction or failure was reported by either the pilot or the operator. (-23)the pilot is assigned night patrol for the Houston police helicopter division. The pilot had received his commerical helicopter rating two days prior to the accident. As part of the initial and currency requirements th e departments has, he was demonstrating autorotations to a landing. After 12 to 13 successful autorotations the pilot bounced the aircraft resulting in a 90 degree turn to the left, a hard landing and causing the main rotor blades to strike the tail boom, cutting it off.