History of Flight
On March 6, 2010, about 1120 central standard time, a Robinson R22 Beta II, N922SH, was substantially damaged when it impacted terrain while maneuvering at low altitude at the Agave Ranch near Cotulla, Texas. The commercial pilot and a passenger were fatally injured. The helicopter was registered to and operated by a private individual. Visual meteorological conditions prevailed, and no flight plan was filed for the 14 Code of Federal Regulations Part 91 local flight. The aerial hog hunting flight was the sixth flight of the morning and had departed around 1110.
According to individuals at the Agave Ranch, the hunting trip was arranged to include an aerial hog hunt. The ranch manager contacted the helicopter owner, who provided the helicopter, pilot, shotgun, and ammunition. The pilot arrived around 0900, towing the helicopter on a trailer, and provided a safety briefing to four hunters. He mentioned each flight would be about 20 minutes and that he would operate the helicopter "light" on fuel for maneuverability.
An initial 5 to 10-minute flight with the ranch manager was conducted to point out ranch perimeters. The pilot then flew three hunters one at a time for about 20 minutes each. The fourth hunter requested a return after about 10 minutes to allow the first hunter more time. Approximately 10 minutes after the last flight departed, waiting hunters heard a sound described as "whoosh whoosh whoosh" or like a lawn mower bogging down. The wreckage was located shortly after.
During each flight, the pilot flew at about the height of a telephone pole at speeds of 0 to 25 mph. The pilot notified the hunter when it was safe to shoot. Between flights, the pilot would exit the running helicopter and add fuel from a tank in his truck. The number of refuelings was uncertain; some reported at least twice, and the ranch manager recalled refueling between each hunter but was unsure about before the last flight. The truck-mounted fuel tank had no gauge to measure fuel dispensed.
Personnel Information
The pilot, age 40, held a commercial pilot certificate for rotorcraft helicopter and an instrument helicopter rating. His last FAA second-class medical was issued on June 24, 2008, with no limitations. A partial flight record submitted showed 498 total hours (303.3 in make/model) as of July 26, 2008. No records were submitted for the period between then and the accident. The helicopter owner estimated the pilot's total time at about 1,000 hours (700 in make/model) at the time of the accident.
Aircraft Information
The two-seat helicopter, serial number 3863, was manufactured in 2005. It was powered by a Lycoming O-360-J2A, 145-hp engine. The last annual inspection was completed April 16, 2008, at an airframe and engine total time of 1,273.3 hours. At the time of the accident, the helicopter had accumulated 1,935 total hours and 27.2 hours since the last 100-hour inspection.
Meteorological Information
At 1053, the automated weather observing system at Cotulla Airport (COT), 12 nautical miles southeast of the accident site, reported wind from 130 degrees at 13 knots, visibility 10 miles, clear of clouds, broken ceiling at 1,700 feet, temperature 64°F, dew point 57°F, and barometric pressure 30.18 inches of mercury.
Wreckage and Impact Information
Investigators from the NTSB, FAA, and Robinson Helicopter Company documented the wreckage. The helicopter impacted an open field on a heading of 190 degrees and came to rest on a heading of 335 degrees. Control continuity was established to all flight controls, and all major components were accounted for.
The fuselage rested upright with downward crushing. The tail boom was bent downward, and the aft end was separated consistent with a main rotor blade strike. The aft section with the tail rotor gearbox was located 127 feet from the main wreckage. Both main rotor blades remained attached; one had a gradual upward curve, the other less curvature with buckling areas.
Main rotor driveshaft continuity was established. The sprag clutch operated normally when rotated. Impact signatures on the swash plate indicated the collective was in the full up position at impact. The automatic carburetor heat control was locked in the cold position. Both fuel tanks contained residual fuel and no hydraulic deformation.
The engine's valve covers and lower spark plugs were removed. Manual rotation established valve train continuity; thumb compression was developed in each cylinder. Both magnetos produced blue sparks when rotated. The oil filter element showed no visible abnormal contaminants.
The carburetor was impact-damaged, with the bowl separated. The fuel inlet screen was clean and unobstructed. The gascolator bowl was separated from the upper housing. Discolored grass (about 5 inches in diameter) consistent with fuel blight was found underneath the helicopter; a live earthworm was found about half an inch below the grass. No other blight was observed on surrounding vegetation.
Medical and Pathological Information
The Webb County Medical examiner's office performed an autopsy on March 7, 2010. The cause of death was reported as "multiple blunt force injuries." Forensic toxicology performed by the FAA CAMI detected no carbon monoxide, cyanide, or ethanol. Chlorpheniramine and Ibuprofen were detected in the urine.
Additional Information
According to the FAA's Rotorcraft Flying Handbook, a height/velocity (H/V) diagram depicts critical combinations of airspeed and altitude for engine failure scenarios. A Robinson R22 Pilot Operating Handbook was located in the wreckage; according to its H/V diagram, the helicopter was being operated in the crosshatched area.