Bell 206L-1AIR EVAC EMS INC
Boonville, IN, USA · 2004-04-21·N137AE
What happened
NTSB summary, verbatimThe helicopter collided with up sloping terrain during a night air medical flight. The accident occurred while transporting a patient from one hospital to another. Examination of the accident site and wreckage revealed the helicopter impacted the terrain in a level flight attitude. The accident site was at an abandoned strip mine located in a rural area. The area contained very few ground structures to provide reference lighting. During post accident interviews the pilot stated that he remembered picking up the patient and the next thing he remembered is the helicopter tumbling. The flight nurse and paramedic on board did not recall there being any indication of a problem prior to impact. The destination hospital is located inside the Class C airspace of the Evansville Regional Airport (EVV). The air traffic control facility at EVV closes at 2300. Between 2328 and 2339, the pilot made 12 attempts to establish contact with approach control as he approached the Class C airspace. There was a time zone change at EVV 16 days prior to the accident. Examination of the cockpit revealed the altimeter was set at 30.08 inches of mercury. The current altimeter setting was 29.77 inches of mercury. This resulted in the altimeter indicating about 310 feet higher then the actual altitude of the helicopter. The pilot who flew the helicopter prior to the accident flight reported the radar altimeter was operating erratically. This pilot and the mechanic who maintained the helicopter, both stated the accident pilot was informed of the problem. Bench testing of the radar altimeter failed to duplicate the reported erratic operation. The decision height (DH) bug on the radar altimeter was found set to 60 feet. Company policy is that the DH bug be set to 500 feet during visual night operations. Examination of the airframe, engine, and flight controls failed to reveal any mechanical failure/malfunction.
Photographs
25the aircraft, and what the investigators foundPhotographs are NTSB docket attachments — works of the US government, in the public domain. Captions are the Board’s own.
Probable cause
the Board's determinationThe pilot's inadequate planning/decision which resulted in his failure to maintain terrain clearance. Contributing factors were the pilot's inadequate preflight planning, his diverted attention, and the dark night conditions.
NTSB analysis
from the final reportThe helicopter collided with up sloping terrain during a night air medical flight. The accident occurred while transporting a patient from one hospital to another. Examination of the accident site and wreckage revealed the helicopter impacted the terrain in a level flight attitude. The accident site was at an abandoned strip mine located in a rural area. The area contained very few ground structures to provide reference lighting. During post accident interviews the pilot stated that he remembered picking up the patient and the next thing he remembered is the helicopter tumbling. The flight nurse and paramedic on board did not recall there being any indication of a problem prior to impact. The destination hospital is located inside the Class C airspace of the Evansville Regional Airport (EVV). The air traffic control facility at EVV closes at 2300. Between 2328 and 2339, the pilot made 12 attempts to establish contact with approach control as he approached the Class C airspace. There was a time zone change at EVV 16 days prior to the accident. Examination of the cockpit revealed the altimeter was set at 30.08 inches of mercury. The current altimeter setting was 29.77 inches of mercury. This resulted in the altimeter indicating about 310 feet higher then the actual altitude of the helicopter. The pilot who flew the helicopter prior to the accident flight reported the radar altimeter was operating erratically. This pilot and the mechanic who maintained the helicopter, both stated the accident pilot was informed of the problem. Bench testing of the radar altimeter failed to duplicate the reported erratic operation. The decision height (DH) bug on the radar altimeter was found set to 60 feet. Company policy is that the DH bug be set to 500 feet during visual night operations. Examination of the airframe, engine, and flight controls failed to reveal any mechanical failure/malfunction.