2008 Robinson R-22 Beta II Accident Near Olalla, Washington (N301MA)

Accident Overview and Flight History On August 17, 2008, at approximately 1455 Pacific daylight time, a Robinson R-22 Beta II helicopter, registration N301MA, struck the ground about two miles northwest of Olalla, Washington. The aircraft was owned and operated by the 68-year-old private pilot, who was the sole occupant and was killed in the accident. The helicopter was destroyed by the impact. The flight was a 14 Code of Federal Regulations Part 91 personal pleasure flight that departed Bremerton National Airport about 20 minutes before the accident. Visual meteorological conditions prevailed, and no flight plan had been filed. The pilot had recently created a landing pad at his residence and intended to fly from Bremerton to his home to test the new pad. He spent 60 to 90 minutes preflighting the helicopter, including refueling with 100 low-lead aviation fuel, before performing practice maneuvers at the airport. After signaling a companion on the ground, the helicopter departed to the east. Witnesses near the pilot's residence observed the helicopter make at least four fly-bys at approximately 200 feet above ground level before it descended and impacted the terrain in the backyard of a residence about one-half mile south of the pilot's house. Witnesses reported various engine sounds, including grinding, high RPM, or sputtering, in the final 10 seconds before impact. ## Personnel and Meteorological Information The pilot held a private pilot certificate with airplane single engine land, airplane single engine sea, and rotorcraft-helicopter ratings. His last third-class medical examination was completed on July 3, 2008. He reported 2,201 total flight hours, with 29 hours in the last six months. His helicopter logbook showed 248.6 total helicopter hours, with the last entry on August 12, 2006. At the time of the accident, weather observations at Bremerton National Airport, Tacoma Narrows Airport, and Seattle-Tacoma International Airport indicated clear skies, 10 statute miles visibility, and temperatures between 27 and 28 degrees Celsius. ## Wreckage and Impact Information The helicopter impacted the southwest corner of a backyard in the 12600 block of Banner Road Southeast in Olalla. During the final descent, the main rotor blades contacted tree limbs at about 20 feet above the ground, followed by the airframe striking a wood fence. The helicopter came to rest on its right side, partially inverted, in dense berry vines. Impact damage was concentrated on the left side of the belly, with the forward part compressed up and aft. The mixture control cable wire was found resting alongside the control arm attach bolt instead of through it, and the mixture control arm was near the full lean position. Fuel was pouring from the helicopter, and an impact hole was found on the auxiliary fuel tank. The tail boom separated, and the tail rotor drive shaft failed, but the tail rotor gearbox and blades showed no significant pre-impact damage. Both main rotor blades were bowed upward with compression wrinkles, and the rotor system components were intact and functional. The engine's throttle was found in the full open position, and the mixture control knob was fully in. ## Medical, Pathological, and Test Information The King County Coroner's Office determined the cause of death to be multiple blunt force injuries to the chest, with the manner of death being accidental. Toxicology tests were negative for carbon monoxide, cyanide, and ethanol, but positive for carvedilol, diphenhydramine, and omeprazole. The pilot's medical application noted the use of carvedilol for high blood pressure and a history of seasonal allergies. The engine was removed and tested at Robinson Helicopter Company, where it ran smoothly with no anomalies after impact-damaged components were replaced. The mixture control cable attachment was examined, and marks indicated the wire had been threaded through the bolt's eye and tightened in place prior to the accident. The carburetor icing probability chart indicated that carburetor ice accumulation could be expected in the ambient environment. The helicopter's carburetor heat assist device was designed to adjust heat based on collective movement, but the pilot was responsible for monitoring the carburetor air temperature gauge and making necessary adjustments.