Plant City, FL, USA
N7188J
ROBINSON HELICOPTER R22 BETA
Shortly after departure, the pilot noted that more than "usual" forward cyclic and collective application was required to maintain the helicopter's desired airspeed, but that a scan of the instruments assured him that "All was okay." While cruising at 700 feet, and 70 knots, the pilot detected a strong odor of burning rubber, a loss of power, illumination of the clutch warning light, and yawing of the helicopter. The pilot entered autorotation, turned to a "dark, open area," and descended into trees. Examination of the helicopter at the scene revealed that the drive belts were twisted, torn, and off of their respective pulleys. Examination and testing revealed that the clutch actuator functioned as designed, but the alignment of the drive belt sheaves and pulleys could not be determined due to impact damage. In a follow-up interview, the pilot stated that during engine start, 10 to 15 seconds transpired between the times that he actuated the clutch switch, and the main rotor blades turned. According to the pilot's operating handbook starting engine checklist, the rotor blades should turn less than 5 seconds after engagement of the clutch switch. According to a note in the manufacturer's maintenance manual, V-Belt Installation, "A delay of more than 5 seconds between clutch switch engagement and rotor turning indicates excessive slack."
HISTORY OF FLIGHT On December 12, 2007, at 1815 eastern standard time, a Robinson R22 Beta, N7188J, was substantially damaged following a forced landing in Plant City, Florida. The certificated private pilot sustained minor injuries. Night visual meteorological conditions prevailed and no flight plan was filed for the personal flight conducted under the provisions of 14 Code of Federal Regulations Part 91. The helicopter departed Lakeland-Linder Regional Airport (LAS), Lakeland, Florida, and was destined for Plant City Municipal Airport (PCM), Plant City, Florida. The pilot was interviewed by telephone, and provided a written statement. He stated that shortly after departure, he noted that more than "usual" forward cyclic and collective application was required to maintain his desired airspeed, but that a scan of the instruments assured him that "All was okay." While cruising at 700 feet, and 70 knots, the pilot detected a "strong odor of burning rubber, a loss of power, the clutch warning light illuminated, and the helicopter yawed." The pilot entered autorotation, turned to a "dark, open area," and descended into trees. Federal Aviation Administration (FAA) inspectors examined the helicopter at the scene, and reported that the helicopter was substantially damaged, and that the drive belts were twisted, torn, and off of their respective drive pulleys. PERSONNEL INFORMATION According to FAA records, the pilot was issued a private pilot certificate on November 7, 2007, with a rating for rotorcraft helicopter. He held a third-class medical certificate issued January 26, 2007. The pilot reported 101 total hours of flight experience, of which 55 hours was in the Robinson R22. AIRCRAFT INFORMATION According to FAA records and the aircraft maintenance records, the helicopter was a Robinson R22 BETA with an airworthiness date of October 4, 2000, and the helicopter had accrued 2,272 aircraft hours. A 2,200-hour overhaul and the last annual inspection were performed on September 14, 2007, at 2,198.5 aircraft hours. The helicopter had flown 73.5 hours since the last annual inspection. METEOROLOGICAL INFORMATION At 1053, the weather reported at PCM included clear skies with winds from 010 degrees at 7 knots. The temperature was 14 degrees Celsius, and the dew point was 3 degrees Celsius. WRECKAGE AND IMPACT INFORMATION Examination of photographs of the wreckage revealed that the helicopter appeared mostly intact. The photos showed damage to the main rotor blades, the upper pylon, the right side windscreen, the tailboom attach point, as well as wrinkling to the cabin. Closer inspection revealed that the drive belts were broken, shredded, and partially wrapped around the lower pulley drive shaft. The helicopter was recovered from the site, and examined in a hangar under the supervision of an FAA aviation safety inspector. Examination and testing revealed that the clutch actuator functioned as designed, but the alignment of the drive belt sheaves and pulleys could not be determined due to impact damage. ADDITIONAL INFORMATION In a follow-up interview, the pilot stated that during engine start, 10 to 15 seconds transpired between the times that he actuated the clutch switch, and the main rotor blades turned. According to the Robinson Helicopter Pilot's Operating Handbook, starting engine checklist, Set engine RPM 50 to 60% Clutch switch Engaged Blades turning Less than 5 seconds According to a note in the Robinson Maintenance Manual, V-Belt Installation, "A delay of more than 5 seconds between clutch switch engagement and rotor turning indicates excessive slack."
A loss of rotor drive due to excessive slack and breakage of the drive belts. Contributing to the accident was the pilot departing in the helicopter after the rotor engagement time during engine start exceeded the time outlined in the pilot's operating handbook.
Source: NTSB Aviation Accident Database
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