HAZELHURST – Two crewmembers on a medical helicopter shouted at the apparent unresponsive pilot seconds before the aircraft crashed in a wooded area near Hazelhurst on April 26, 2018, according to the National Transportation Safety Board (NTSB).
The crash of the Eurocopter AS350 B2 helicopter shortly before 11 p.m. that night took the lives of 34-year-old commercial pilot Rico Caruso of Hazelhurst, and EMS crewmembers 43-year-old Gregory Rosenthal of Mosinee, and 30-year-old Klint Mitchell of Watersmeet, Michigan.
The NTSB wrapped up the second stage of its 2-year investigation with its factual report issued Tuesday, May 5. As part of their fact gathering, investigators retrieved data from the helicopter’s on-board Appareo Vision 1000 recorder, which records image, audio and parametric data. Those devices are oftentimes referred to as “black boxes.”
The final stage in the investigation process will be a determination of “probable cause” and analysis of facts, according to Peter Knudson, a media spokesman for the NTSB. “In this case,” he said, “the NTSB will delegate the Office of Aviation Safety (OAS) to make that determination.” The recommendation of the investigators on probable cause goes “through several layers of management” before the OAS signs off on it.” It could be several months before the final report is issued, he added.
The Air Methods Corporation helicopter was en route back to Woodruff after transferring a patient from Howard Young Medical Center; departing at 6 p.m. to the Merrill Municipal Airport, picking up another patient and then arriving to UW Hospital in Madison at 7:37 p.m. where the patient was offloaded. The crew then refueled at Dane County Regional Airport in Madison. “The pilot conducted a preflight of the helicopter with the engine operating, and no anomalies were detected,” before departing at 9:07 p.m., the report says. An autopsy on the pilot showed no evidence for alcohol or other “tested-for substances.”
The investigation did not reveal any damage or malfunction to the aircraft prior to the crash. Nor was there any evidence of a bird strike. While the report does not point to a specific cause, it does list pilot’s “lost of control in flight,” noting the helicopter banked unexpectedly at about 10:43 p.m. “The roll rate to the right appeared to increase rapidly, and the pilot’s body, right forearm, and right hand (which was holding the base of the cyclic grip) appeared to move along with the increased roll rate,” investigators concluded. The cyclic is used to control the main rotor in order to change the helicopter's direction of movement. On board recordings then showed a crewmember twice saying, “What are we doin’?” The pilot’s head sagged out of view of the camera. Both crewmembers then shouted the pilot’s name as the helicopter’s roll increased to more than 90 degrees. The pilot did not respond, the report says. The helicopter turned upside down just prior to the crash, the report says. All three perished at the scene.
The report looked into how much rest the pilot had gotten before the flight, but drew no conclusions. Voice recordings upon departure from Madison did pick up “Yawning and sighs,” but the report did not indicate from whom. “After about 2215 (10:15 p.m.), the medical crewmembers started non-aviation-related conversations, and the pilot was last heard during the conversations about 2229 (10:29 p.m.),” the report adds.
