History of Flight
On August 6, 2013, at about 1030 central daylight time, a Bell 47G-3B-1 helicopter, registration N83702, made a forced landing after experiencing a decrease in engine performance near Vinton, Iowa. The commercial pilot, the sole occupant, was not injured. The helicopter was substantially damaged. The aircraft was registered to Benedict Fluke and operated by Speas Aviation Inc. under 14 Code of Federal Regulations Part 137 as an aerial application flight. Visual meteorological conditions prevailed and no flight plan was filed. The local flight was departing at the time.
The pilot reported that the helicopter was loaded with 60 gallons of spray product. After lifting off from the truck bed, the rotor rpm decreased, prompting the pilot to land. The pilot then lifted off from the ground and observed no anomalies. He flew forward at 20 feet above ground level (AGL) and 20–25 miles per hour groundspeed over a bean field. Rotor rpm decreased again, and the pilot elected to land. The helicopter struck the ground tail-low, damaging the tail rotor and tail boom.
Pilot Information
The pilot, age 46, held a commercial pilot certificate with helicopter and instrument helicopter ratings, as well as a flight instructor certificate for helicopters. He reported 1,352 total flight hours, of which 1,315 were in helicopters and 210 in the accident make and model. He had logged 41 hours in the accident helicopter in the preceding 30 days.
Aircraft Information
The Bell 47G-3B-1 is a four-seat, single-engine, agricultural-equipped helicopter built in 1966. An annual inspection was completed on July 17, 2013. According to the pilot, the helicopter had accumulated 77 hours of total flight time, with 41 hours since the last annual inspection. The maximum gross weight was 2,850 pounds.
Weather Conditions
At 1035, an automated weather report from Vinton Veterans Memorial Airpark, about 10 miles northeast of the accident, indicated wind from 240 degrees at 3 knots, 10 miles visibility, clear skies, temperature 27°C, dew point 22°C, and barometric pressure 29.89 inches of mercury. The pilot reported variable wind favoring 180 degrees at 3 to 5 knots.
Wreckage and Impact Information
The helicopter came to rest upright in a bean field. The main and tail rotor blades struck the ground and sustained damage. The tail boom separated from the fuselage. A postaccident examination by an FAA inspector revealed no mechanical malfunctions or failures that would have precluded normal operation.
Additional Information
Video from a handheld recording device showed the pilot flying the helicopter off the truck bed, traveling about 50 yards at roughly 10 feet AGL, then landing in tall grass. Shortly after, the helicopter lifted off again, flew over a bean field for about 100 yards, descended, and executed a forced landing straight ahead, striking the ground tail-low. A representative of Scott's Helicopter Services, the type-certificate holder, noted that after the first landing in grass, the pilot should have assessed weight and balance and possibly off-loaded applicant. The engine sounds were normal during takeoff but then sounded "lugged down" as the takeoff continued.
Weight and balance calculations by the FAA inspector showed the helicopter was loaded 16 pounds under maximum gross weight. Density altitude at the time was calculated at about 2,800 feet.