Eurocopter AS350B2 crash near Eufaula, OK, United States

HISTORY OF FLIGHTOn March 12, 2015, about 2315 central daylight time, a Eurocopter AS350 B2 helicopter, N919EM, impacted trees and terrain while maneuvering near Eufaula, Oklahoma. The commercial pilot was fatally injured, and the two medical crewmembers sustained serious injuries. The helicopter was destroyed. The helicopter was registered to and operated by Eagle Med, LLC, Wichita, Kansas, as Eagle Med 35, a 14 Code of Federal Regulations Part 135 emergency medical services (EMS) positioning flight. Dark night visual meteorological conditions prevailed at the time of the accident, and a company visual flight rules flight plan had been filed. The helicopter departed from St. Francis Hospital Heliport (4OK3), Tulsa, Oklahoma, about 2248 and was destined for McAlester Regional Airport (MLC), McAlester, Oklahoma. According to the two medical crewmembers, one of whom was an emergency medical technician (EMT) and one of whom was a flight nurse, the crew checked the weather before the previous flight to transfer a patient to 4OK3, and the report showed ceilings at 8,500 ft and 6 miles visibility at MLC and ceilings at 10,000 ft. at 4OK3. During the flight to transport the patient, the pilot stated that the clouds above their cruise altitude were lower than he expected. The pilot descended the helicopter and then landed it at 4OK3 without incident. While on the ground at 4OK3, the pilot checked the weather conditions again , and they were the same. The pilot conferred with the medical crew per their risk management procedures, and they decided to return to MLC as planned. The helicopter took off and headed southbound at a cruise altitude of about 1,500 ft. mean sea level (msl) in an area with a terrain elevation of about 700 to 900 ft. msl. The EMT, seated in the far left back seat, stated that they were about halfway to MLC when they suddenly entered instrument meteorological conditions (IMC). He recalled the pilot saying that this was "not good." He told the pilot to climb to 3,500 ft., but he did not think the pilot initiated a climb. He also told the pilot that he could see lights on the horizon. The pilot asked him to "tell him about those lights." He told the pilot, "They are to the left" and gestured a left turn with his hands. The EMT said that he then saw a strobe flash and trees and said, "pull up," but the helicopter crashed. The flight nurse, seated in the far right back seat, stated that as they departed the Tulsa area, she began monitoring their route on the chart. She added that they were practicing a procedure regarding inadvertently encountering IMC when the EMT said, "We're in a cloud." The pilot responded, "What do I do now?" and the EMT answered, "go up." The pilot then said that he was proceeding to Okmulgee, Oklahoma, because he could see lights to the left. He then said, "I'm turning left." When he started the turn, the EMT began yelling "pull up." The pilot then said, "What's that noise?" The EMT responded, "that's your 500" (altitude warning). The flight nurse said she started seeing trees and then did not see or hear anything after that. The helicopter had an EMS Sky Connect GPS transmitter that sent 39 messages to the company containing location information and device power status. The last three messages showed the helicopter as it approached the accident site. The third-from-the-last message showed the helicopter on a 173° heading at 414 ft. and a ground speed of 118 knots. The next-to-last message showed the helicopter on a 146° heading at 397 ft. and a ground speed of 110 knots. The last message showed the helicopter on a 172° heading at 380 ft. and a ground speed of 119 knots. PERSONNEL INFORMATIONThe pilot held a commercial pilot certificate with single-engine land airplane, helicopter, and instrument ratings. On August 23, 2014, he was issued a second-class medical certificate with no limitations. Company records showed that the pilot had flown 2,384.7 total hours and 7.6 hours in the 30 days before the accident. The records also showed that the pilot successfully completed a flight review in the accident make and model helicopter on February 24, 2014. AIRCRAFT INFORMATIONThe four-place, single-engine helicopter, serial number 4113, was configured for EMS transport. It was equipped with a single 143-gallon fuel tank and was powered by a 712-horsepower Turbomeca Arriel 1D1 turboshaft engine, serial number 19080. A review of the company's maintenance records revealed that the helicopter was maintained under a company aircraft inspection program and had undergone a 100-hour inspection on March 9, 2015, at total airframe time of 1,935.2 hours. The Hobbs meter was recovered at the accident site, and it read 1,941.5 hours. The Federal Aviation Administration (FAA) conducted a ramp inspection of the Eagle Med facility on March 11, 2015, that revealed discrepancies with the night vision goggle (NVG) lighting system and the radio altimeter indicator. The NVG system and radio altimeter were deferred until a 100-hour inspection could be completed on the NVG system and a filter could be replaced on the radio altimeter indicator. Until that was completed, helicopter night vision goggle operations were not permitted. METEOROLOGICAL INFORMATIONA meteorological reporting station was located at Okmulgee Regional Airport, Okmulgee, Oklahoma, about 20 miles north-northwest of the accident location at an elevation of about 720 ft. A 2315 automated weather report indicated wind from 020° at 3 knots, visibility of 10 statute miles or greater, ceiling broken at 2,400 ft. above ground level (agl), broken cloud layer base at 3,000 ft. agl, temperature 12° C, dew point temperature 11° C, and an altimeter setting of 30.13 inches of m ercury. From 2015 to 2315, the reported cloud layer was generally at or above 5,000 ft. agl; however, at 2255 (20 minutes before the accident), the reported cloud layer was scattered at 1,100 ft. agl. A meteorological reporting station was located at MLC about 28 miles south of the accident location at an elevation of 770 ft. At 2053, MLC reported overcast clouds with bases at 9,000 ft. agl. Beginning at 2153 and continuing through the accident time, MLC automated reports indicated that the lowest cloud bases were between 900 and 2,100 ft. agl. AIRPORT INFORMATIONThe four-place, single-engine helicopter, serial number 4113, was configured for EMS transport. It was equipped with a single 143-gallon fuel tank and was powered by a 712-horsepower Turbomeca Arriel 1D1 turboshaft engine, serial number 19080. A review of the company's maintenance records revealed that the helicopter was maintained under a company aircraft inspection program and had undergone a 100-hour inspection on March 9, 2015, at total airframe time of 1,935.2 hours. The Hobbs meter was recovered at the accident site, and it read 1,941.5 hours. The Federal Aviation Administration (FAA) conducted a ramp inspection of the Eagle Med facility on March 11, 2015, that revealed discrepancies with the night vision goggle (NVG) lighting system and the radio altimeter indicator. The NVG system and radio altimeter were deferred until a 100-hour inspection could be completed on the NVG system and a filter could be replaced on the radio altimeter indicator. Until that was completed, helicopter night vision goggle operations were not permitted. WRECKAGE AND IMPACT INFORMATIONThe accident site was located atop a wooded hill on an embankment next to a creek about 9 miles west of Eufaula at an elevation of 840 ft. msl. The helicopter came to rest on its right side and was oriented on an easterly heading. (See figure 1 for a photograph showing the accident site and main wreckage.) Figure 1. A photograph showing the accident site and main wreckage. The initial impact point was a tree about 190 ft. west of the main wreckage. Several trees in the immediate vicinity of the helicopter were broken and showed marks that corresponded with