19970221045249A

(.19) On February 21, 1997, about 0909 hours hawaiian standard time, a Hughes HU-369-D, N505RM, operated by manuiwa airways, inc., d.b.a. volcano hili-tours, experienced the loss of its tail rotor assembly during cruise flight. The flight was operating under 14 CFR part 135. The helicopter was substantially damaged during the pilot's forced landing on rough terrain about 5 miles southeast of Milolii, Hawaii. The commercial pilot and two passengers were seriously injured. The fourth passenger received minor injuries. Visual meteorological conditions prevailed, and a company VFR flight plan was filed. The local flight originated from a remote area approximately 1.4 miles north of the crash site about 0850. The purpose of the flight was to transport personnel from the state of Hawaii's department of land and natural resources, division of forestry and wildlife, to a work site within the manuka forest reserve, in the south kona district of the island of Hawaii. The personnel had been directed to spray fountain grass. The passengers and their equipment boarded the helicopter, and the flight commenced. The pilot did not report that anything unusual occurred until after he leveled off at 90 knots airspeed and 400 feet mean sea level. The pilot indicated that about 1 minute after taking off he heard a loud bang, and immediately thereafter he felt a slight shudder in the tail rotor pedals. When he applied pressure to the tail rotor pedals there was no response. Seconds later the helicopter entered a steep left nose tuck attitude. The pilot reported that he regained control, flew for several minutes, and then began an autorotation. The helicopter touched down hard in an area covered with vegetation and rolled over. The engine continued operating and the main rotor blades continued rotating after the ground impact. The left rear seated passenger reported that about 1 minute into the flight he heard a loud bang. Thereafter, he observed pieces of tail rotor blades flying past the left side of the helicopter. (.4) the purpose of the flight was to transport state employees to a nearby work site. The pilot took off, climbed to about 400 feet MSL, and accelerated to 90 knots. The first minute of flight was routine, and the pilot did not indicate he was experiencing any malfunctions. Suddenly, a loud bang was heard which was followed by a slight shudder in th e tail rotor pedals. A passenger reported observing pieces of the tail rotor blades flying past the left side of the helicopter. The pilot applied pressure to the tail rotor pedals but no response was evident. The pilot autorotated to a hard landing on rough terrain covered with vegetation. The helicopter was recovered and examined. No evidence of mechanical problems was found. The tail rotor blade assemble was not located. Prior to the flight the helicopter's doors had been removed. Also, 2 days earlier, company maintenance personnel had replaced one of the two tail rotor pitch change links due to excessive wear in its rod end bearing.