19990309002109A

San bernadino county sheriff's department public use 1997 MD-600N helicopter crashed under unknown circumstances in the san bernadino mountains near lake silverwood, CA. (.19) on March 9, 1999, about 1750 hours pacific standard time, a Mcdonnell Douglas 600N, N626SB, inadvertently entered instrument meteorological conditions (IMC) and collided with mountainous terrain about 7.4 niles north of Rialto, California. The helicopter was substantially damaged. The commercial pilot and flight observer (crewmember) were not injured. A passenger sustained minor injuries. The aircraft was operated by the san bernardino county sheriff department, san bernardino, California, as a public-use aircraft under the provisions of 14 CFR part 91. The local patrol flight originated at the Rialto, California, airport, about 1710. Instrument meteorological conditions prevailed at the accident site. A company visual flight rules (VFR) flight plan was filed. The pilot reported that they were flying a routine patrol mission in a mountainous area about 4,800 feet MSL. The flight crew observed an abandoned vehicle and decided to investigate the circumstances. The pilot approached the hill and landed. The observer exited the aircraft to look at the car and the pilot orbited the area. The pilot reported that when he did a left pedal turn, he could see the valley floor. He staed that the weather conditions were approximately a 500- to 600-foot ceiling and 10 miles visibility. By the time the observer reentered the helicopter, a low cloud ceiling had moved in. The pilot took off and made a right turn while descending toward the valley floor. The floor was obscured from view. The pilot reported that he then pulled power and began a climb while heading south. The observer then reported that he could see the ground beneath them, and the pilot looked down for about "4 to 5 seconds." When he looked up, he realized that the helicopter was no longer climbing. He stated that the radio magnetic indicator (rm) indicated that the aircraft was in a right-hand spin, so he applied opposite pedal and leveled the aircraft. The aircraft nose tucked down and the spin increased in intensity. The helicopter had lost some altitude and was now headed in a westerly direction inside a canyon. To gain altitude, the pilot pulled power, leveled the ship, and initiated a climb. The helicopter then began a second spin, which was more "violent" than the first. The pilot reported that the attitude indicator showed a near-level attitude, but the rmi continued to spin and he felt a negative (g) (gravity) force. He began a slow left turn toward the south and saw a mountain just ahead of the aircraft so he slowed the aircraft's rate of descent. The helicopter impacted terrain on a narrow mountain ledge. The right skid impacted first and the aircraft then filled approxiamtely 15 degrees to the right. The pilot reported that there was no other movement of the helicopter after impact. He estimated that the helicopter's airspeed at the time of impact was near zero. He further estimated that the entire sequence of events, from takeoff to impact, lasted about 1 to 1 1/2 minutes. Because of the adverse weather and terrain, the personnel were not rescued until 0400 on March 10, 1999. The pilot remained in contact with the dispatch center throughout the night. (.4)during a routine law enforcement patrol flight, the pilot responded to the 4,700-foot mean sea level mountainside to investigate circumstances related to an apparent abandoned vehicle. Upon arriving at the site, the pilot performed a toe-in landing to discharge his crewmember. The crewmember proceeded to evaluate the vehicle while the pilot orbited the area. While orbiting, the pilot observed that low elevation clouds were approaching. However, the visibility initially was about 10 miles, and the clouds height appeared between 500 and 600 feet above the ground. After a few minutes, the crewmember returned to the helicopter, and they departed. Seconds after taking off the pilot lost visual reference with the ground as he inadvertently entered the clouds. The pilot lost control of the helicopter and it impacted the terrain. (-23)LAX99TA115