|Image courtesy WSAW|
This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed.
National Transportation Safety Board
Aviation Accident Preliminary Report
Location: Hazelhurst, WI Accident Number: CEN18FA149
Date & Time: 04/26/2018, 2250 CDT Registration: N127LN
Aircraft: EUROCOPTER AS 350 B2 Injuries: 3 Fatal
Flight Conducted Under: Part 91: General Aviation - Positioning
On April 26, 2018, about 2250 central daylight time, a Eurocopter AS 350 B2 helicopter,
N127LN, impacted trees and terrain during cruise flight near Hazelhurst, Wisconsin. The pilot
and two crewmembers were fatally injured. The helicopter was destroyed during the impact.
The helicopter was registered to and operated by Air Methods Corporation as a Title 14 Code of
Federal Regulations Part 91 repositioning flight. Night visual meteorological conditions were
reported in the area about the time of the accident, and the flight was operating on a company
visual flight rules flight plan. The flight originated from the Dane County Regional Airport-
Truax Field (MSN), near Madison, Wisconsin, about 2104 and was destined for the Howard
Young Medical Center Heliport (60WI), near Woodruff, Wisconsin.
Earlier in the day the emergency medical services (EMS) crew had transported a patient to the
Madison area. The purpose of this flight was to reposition the helicopter back to 60WI. The
helicopter was serviced with 80 gallons of fuel at MSN. According to initial information, the
pilot radioed that he departed from MSN. The helicopter did not arrive at its destination at its
estimated arrival time, and the operator started their search procedures for the helicopter. The
Air Force Rescue Coordination Center placed a call to the operator and advised that an
emergency locator transmitter signal associated with the helicopter was received by the center.
The center informed the operator of a latitude and longitude in which to look for the helicopter.
The helicopter was subsequently found near that location about 0215 on April 27, 2018.
The 34-year-old pilot held a Federal Aviation Administration (FAA) commercial pilot
certificate with rotorcraft-helicopter and instrument helicopter ratings. He also held a private
pilot certificate with an airplane single engine land rating. He held an FAA second class
medical certificate issued on May 31, 2017. On his last application for the medical certificate
the pilot reported having accumulated 3,200 hours of total flight time, with 100 hours logged
with the preceding six months. According to initial information from the operator, the pilot
received training on January 5 and 7, 2018 and satisfactorily passed a check ride.
N127LN was a 2006 model Eurocopter (Airbus) AS 350 B2, four-place, single-engine
helicopter, with serial number 4149. The helicopter was configured for EMS transport services.
It was powered by a Turbomeca Arriel 1D1 turboshaft engine, with serial number 19129. The
engine had a maximum takeoff power rating of 732 shaft horsepower and a continuous power
Page 2 of 4 CEN18FA149
rating of 625 horsepower. According to initial information, the helicopter was maintained
under a company aircraft inspection program and had undergone 100 and 600-hour
inspections on April 25, 2018, at an airframe total time of 5,152.8 hours. The helicopter was not
equipped with a vehicle engine multifunction display or a digital electronic control unit.
However, it was equipped with an enhanced ground proximity warning system (EGPWS).
At 2255, the recorded weather at the Lakeland Airport/Noble F. Lee Memorial Field, near
Minocqua, Wisconsin, was: Wind calm; visibility 10 statute miles; sky condition clear;
temperature 0° C; dew point -1° C; altimeter 29.88 inches of mercury.
At 2253, the recorded weather at the Rhinelander-Oneida County Airport, near Rhinelander,
Wisconsin, was: Wind calm; visibility 10 statute miles; sky condition clear; temperature 2° C;
dew point 1° C; altimeter 29.87 inches of mercury.
At 2253, the recorded weather at the Eagle River Union Airport, near Eagle River, Wisconsin,
was: Wind calm; visibility 10 statute miles; sky condition clear; temperature 0° C; dew point 0°
C; altimeter 29.86 inches of mercury.
According to U.S. Naval Observatory Sun and Moon Data, the end of local civil twilight in the
Rhinelander, Wisconsin, area was 2031 and local moonset was at 0507 on April 27, 2018. The
observatory characterized the phase of the moon as "waxing gibbous with 88% of the Moon's
visible disk illuminated."
The helicopter was found in a wooded area about 178° and 8.4 nautical miles from 60WI. First
responders indicated that the sky was clear, the moon was visible, and there was a smell of fuel
at the time the helicopter was located. However, the wreckage did not exhibit any signs of fire.
A tree about 70 ft tall about 66° and 47 feet from the nose of the wreckage had branches broken
in its upper canopy. Trees in between this tree and the wreckage had their trunks and branches
broken and linearly separated. The path of the broken and separated trunks and branches
through the trees was steep. A ground impression about 11 ft by 9 ft and 2 ft deep was found in
front of the helicopter wreckage. The helicopter came to rest on its right side. The heading of
the wreckage from tail to nose was about 095°.
During the on-scene examination, the smell of
fuel was present at the site and in the ground below the helicopter. All major components of
the helicopter were located at the site. The cockpit and cabin area was destroyed. The fuselage
exhibited rearward crushing deformation. The tailboom was attached to the fuselage. The tail
rotor gear box and tail rotor blades remained on the tail. However, the vertical fin had partially
detached from the end of the tailboom. Both horizontal stabilizers were present on the tail. All
three rotor blades remained attached to the rotor hub, and the rotor hub was attached to the
transmission. The main rotor blades exhibited damage to include spar fractures and leadingedge
abrasions and depressions.
The main rotor hub rotated when the transmission's input drive shaft was rotated by hand. The fuel tank was fragmented. Yaw, pitch, lateral, and collective controls were traced from the cockpit to their respective servo actuators.
Engine controls were traced from the cockpit through their respective bellcranks to their engine
components. A magnetic plug in the hydraulic system had some particulate on its magnetic
end. The filter bypass button on the hydraulic control block was popped. The hydraulic pump
was turned by a drill and the pump exhibited a suction and pressure at the pump's inlet and
outlet. Disassembly of the hydraulic pump revealed scoring witness marks on the pump
Page 3 of 4 CEN18FA149
housing in its gear's plane of rotation and no debris or obstructions were observed within the
The engine was found on the ground and was separated from the fuselage. The engine's
compressor blades exhibited nick and gouge damage consistent with foreign object ingestion.
The power turbine blades exhibited silver colored deposits on them. The power turbine was
turned by hand and the drive train did not turn. Subsequent examination revealed that the
engine's Module 5 reduction gearbox had migrated out of its installed position, rearward, to the
extent its O-ring groove was visible. The Module 5 gearbox was removed for inspection of the
input pinion torque alignment marks. The marks were found to be misaligned approximately 2
millimeters in the tightening direction which is consistent with engine power being delivered to
the drive train during the main rotor blade impact sequence.
The Oneida County Coroner was asked to perform an autopsy on the pilot and to take
The helicopter was equipped with an Appareo Vision 1000 recorder unit, which records to both
a removable secure data (SD) card and internal memory. Both the unit and the SD card
sustained impact damage. The unit and its SD card were shipped to the National
Transportation Safety Board Recorder Laboratory to see if they contain data in reference to the
accident flight. (emphasis added)
A hydraulic fluid sample and a fuel sample were retained for testing.
Additionally, the hydraulic magnetic plug, the hydraulic pump, hydraulic filter, four actuators,
and the EGPWS were retained for further examination.
Aircraft and Owner/Operator Information
Aircraft Make: EUROCOPTER Registration: N127LN
Model/Series: AS 350 B2 NO SERIES Aircraft Category: Helicopter
Amateur Built: No
Operator: AIR METHODS CORP Operating Certificate(s)
On-demand Air Taxi (135)
Operator Does Business As: Operator Designator Code: QMLA
Page 4 of 4 CEN18FA149
Editor's note: These guys were just.like.us. What happened to them could happen to us. Let us never forget these good souls. Let us keep their families - who will suffer for this until the end of their days - in our hearts. And let us resolve to learn from this tragedy in order to prevent something like this from happening again.