History of Flight
On July 19, 2021, at about 1600 central daylight time, a Robinson R44 II helicopter, registration N44BJ, was destroyed in an accident near Elgin, Minnesota. The helicopter was operated under Title 14 Code of Federal Regulations Part 137 as an aerial application flight. A witness observed the helicopter completing east and west spray passes over a cornfield, with each pass progressively closer to the north end of the field. The witness saw the helicopter make two consecutive spray passes over powerlines crossing the field; during the third spray pass, the helicopter flew underneath the powerlines while heading west. Shortly after the witness entered a nearby pole barn, a loud boom was heard and the building shook. The witness exited and saw smoke rising from the cornfield. He and another person responded to the accident site and found the helicopter engulfed in flames.
Personnel Information
The Federal Aviation Administration (FAA) revoked the pilot's second-class medical certificate in a letter dated February 22, 2021. The pilot had been seriously injured in a forced landing accident approximately 11 months earlier. The FAA had sent a letter on August 10, 2020, requesting a medical examination to determine if the pilot remained qualified for a second-class medical certificate, but the pilot did not undergo the requested evaluation. On May 17, 2021, the pilot completed an application for a new medical certificate. On that application, he reported 4,000 total flight hours, with 1,100 hours in the previous six months, and answered "no" when asked if his medical certificate had ever been revoked. The aviation medical examiner requested information about the previous accident, but the pilot had not provided the records before the accident occurred. The pilot's logbook contained a single endorsement for required training under Special Federal Aviation Regulation 73 to act as pilot-in-command of a Robinson R44 helicopter; the date of the endorsement was not recorded.
Aircraft Information
According to the Robinson R44 II Pilot Operating Handbook, the helicopter's height was 10.75 ft. The operator stated that during aerial application flights, the helicopter was typically flown 10 ft above the crop to ensure optimal spray disbursement. Postaccident review of available maintenance documentation revealed no unresolved maintenance tasks or issues with the helicopter.
Meteorological Information
At the time of the accident, the sun's position relative to the accident site was along a west-southwest heading (249° true) and about 48.6° above the horizon.
Wreckage and Impact Information
The initial impact location was a multiphase power transmission line. The transmission line consisted of 24 aluminum-conducting strands over 7 steel strands, with three lines present. The western line remained intact, the center line was frayed, and the eastern line was severed. The damaged transmission line was about 28 ft above the ground. The corn crop under the lines was 8 to 10 ft tall. Portions of the swashplate yoke, a blade droop tusk, the pilot's headset, and plexiglass fragments were found under and immediately east of the powerlines. The wreckage debris path measured 292 ft between the powerlines and the main wreckage, on a 090° heading. The helicopter impacted terrain at a 15° descent angle. Fractured spray booms, cabin door, and plexiglass were scattered along the path. The main wreckage included remnants of the cabin, landing skids, cockpit, engine, main rotor transmission, main rotor head and blades, aft fuselage, sheaves, tail rotor driveshaft, tailboom, tail rotor gear box, and tail rotor blades. The product tank was relatively intact, with its support frame about 15 ft north of the main wreckage. Most of the cabin and cockpit were destroyed by postimpact fire. Flight control continuity could not be established due to extensive damage. One main rotor blade remained intact but folded in half; the other fractured about 3 ft from the tip, with damage consistent with impact with a power transmission line. The outboard 3 ft of that blade was found about 465 ft south of the powerline strike. Postaccident examination found no evidence of a pre-existing mechanical malfunction or failure that would have prevented normal operation.
Medical and Pathological Information
An autopsy performed at the Mayo Clinic in Rochester, Minnesota, determined the cause of death as blunt force and thermal injuries. Toxicology testing by the FAA Forensic Sciences Laboratory detected no carboxyhemoglobin, ethanol, or tested-for drugs.