NTSB Factual Report

HISTORY OF FLIGHT

On June 6, 2013, about 2315 eastern daylight time, a Bell 206 L-1, N114AE, was destroyed when it impacted the ground in an elementary school parking lot while on approach to the company's helicopter landing zone near Manchester, Kentucky. Night visual meteorological conditions prevailed; however, reports of patchy fog were reported by numerous eyewitnesses and a company visual flight rules flight plan was filed. The airline transport pilot and two medical personnel were fatally injured. The helicopter was owned and operated by Air Evac EMS Inc. and was operated under the provisions of Title 14 Code of Federal Regulations Part 91 as a repositioning flight to the company-owned helipad. The flight originated from the St. Joseph-London Heliport (5KY9), London, Kentucky about 2259.

Numerous eye and auditory witness statements were recorded by the Kentucky State Police and reported to the NTSB for reference. Several eyewitnesses reported to the State Police that the helicopter was observed "flying lower than normal" and "spinning" prior to impact. Some of the eyewitnesses reported that there was no fog in the area and the sky was clear at the time of the accident. Other eyewitnesses reported that while driving down the road that ran in front of, and parallel to, the elementary school, and located between the accident site and the intended landing location, they observed the helicopter in a nose down attitude, impact the ground, and subsequently engulfed in a fireball; however, they also stated the visibility at the time was around 1/4 mile. The eye and auditory witnesses that reported the clear skies were at their residence about 1/2 mile from the accident site on the opposite side of the creek that ran along the back side of the school. One of the eyewitnesses observed the helicopter in a tail low attitude, then in a more level attitude prior to the engine noise ceasing, which took place prior to the accident.

PERSONNEL INFORMATION

According to Federal Aviation Administration (FAA) and company records, the pilot held an airline transport pilot certificate with a rating for airplane multiengine land and a held a type rating in CE-500 airplanes, a commercial pilot certificate with ratings for airplane single-engine land, helicopter, and instrument helicopter, and a control tower operator certificate with limitations for Simmons Army Airfield, NC GCA only. He also had a flight instructor certificate for airplane single-engine, multiengine, and instrument airplane. He held a second-class medical certificate, which was issued on January 4, 2013, and had one restriction of "must have available glasses for near vision."

According to company records, the pilot was hired on February 16, 2013. At that time the pilot reported that he had 4,877 total hours of flight experience and 1,902 flight hours in helicopters, of which, 1,600 total flight hours were in Bell 206/OH 58 Helicopters. Since the start of his employment, the company had recorded 54.4 total flight hours for the pilot, not including the flights on the day of the accident. The pilot had completed ground training on February 16, 2013, and flight training on March 3, 2013, in the handling and use of the ITT Model F4949 night vision goggles. The operator reported that the pilot had no previous recorded night vision goggle flight time, and that since employment, he had logged 13.2 total hours of night vision goggle experience.

According to records provided by the operator, in the 3 days preceding that accident, the pilot had worked 3 shifts with a total of 36.6 hours of duty and 2.5 hours of total flight time. According to the company records, during that period of time the pilot had 53.2 total hours of "Hours Off" time.

AIRCRAFT INFORMATION

According to FAA and company records, the helicopter was issued an airworthiness certificate on September 26, 1980 and was registered to Air Evac EMS, Inc on October 31, 2002. It was equipped with an Allison 250-C30P engine, with 650 shaft horsepower. The helicopter was modified with enhanced power and increased payload, which gave it a further designation of an "L-1 Plus." The helicopter was on an Approved Airworthiness Inspection Program (AAIP) and its most recent event 1 inspection was completed on June 6, 2013. The helicopter was equipped with a SkyTrac system, which recorded data in 5 second intervals and some of the data was transmitted to the operator's enhanced operation control center (OCC) once every minute.

COMMUNICATIONS

Communication recordings obtained from the operator, indicated that at 2312:24, the pilot announced that "one oh nine roger show us arriving at the base" followed by the Operators Central Communication (CENCOM) responding at 2312:30, with "air evac one oh nine got you on final for base." At 2315:02, a recording of a male voice was captured and stated "no." No other recordings were captured for the accident flight.

METEOROLOGICAL INFORMATION

The 2339 recorded weather observation at London-Corbin Airport-Magee Field (LOZ), London, Kentucky, included calm wind, 2 1/2 miles visibility due to mist, scattered clouds at 8,000 feet above ground level (agl), temperature 19 degrees C, dew point 19 degrees C, and a barometric altimeter of 29.80 inches of mercury

The 2253 record weather at LOZ included calm wind, 6 miles visibility due to mist, scattered clouds at 5,500 feet agl, temperature 20 degrees C, dew point 19 degrees C and a barometric altimeter of 29.81 inches of mercury.

The NWS Surface Analysis Chart for 2300 EDT depicted a low-pressure center very near the accident location, with a cold front extending southwest, and a warm front extending east from the low-pressure center. A separate cold front was advancing from the north through the northern portion of Kentucky. Surface temperatures in eastern Kentucky and eastern Tennessee were generally in the high 60's° F. Dew point temperatures were in the mid- to high 60's°F. Station models depicted the wind as calm or light, with one station near the accident site reporting mist.

A NWS Weather Depiction Chart for 0000 EDT on June 7, 2013, depicted fronts in a similar fashion to the Surface Analysis Chart. In addition, the Weather Depiction Chart, which provides contours for areas of IFR and MVFR conditions, indicated the accident location was in an area of VFR conditions with ceilings greater than 3,000 feet agl and a visibility greater than 5 miles.

An Area Forecast Discussion (AFD) was issued at 2053 EDT by the NWS Weather Forecast Office in Jackson, Kentucky (KJKL). The aviation portion of the AFD, which was originally issued at 2005 EDT in a previous AFD, was:

FXUS63 KJKL 070253 AAB AFDJKL

AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE JACKSON KY

1053 PM EDT THU JUN 6 2013

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING) ISSUED AT 805 PM EDT THU JUN 6 2013

ISOLATED CONVECTION IS POSSIBLE UNTIL AN HOUR OR TWO PAST

SUNSET AT THE TAF SITES AND WELL INTO THE NIGHT OVER THE FAR SOUTHEAST. FOG OR LOW STRATUS DEVELOPMENT CANNOT BE RULED

OUT AT THE TAF SITES...BUT THERE MAY BE ENOUGH CLOUDS THROUGH THE NIGHT TO KEEP CONDITIONS FALLING AS LOW AS MUCH OF THE GUIDANCE SUGGESTS. LAMP AND OTHER GUIDANCE SUGGESTS CONDITIONS FALLING TO NEAR...IF NOT BELOW AIRPORT MINIMUMS OVERNIGHT. CONFIDENCE IN THIS WAS NOT ALL THAT HIGH DUE TO UNCERTAINTY IN CLOUD COVER OVERNIGHT...BUT OPTED TO TREND IN A PERIOD OF IFR AT THE TAF SITES BETWEEN ABOUT 7Z AND 14Z.

WINDS SHOULD BE LIGHT AND VARIABLE THROUGH THE PERIOD.

One Airmen's Meteorological Information (AIRMET) advisory was active at low altitudes for the accident location at the accident time. This AIRMET for IFR conditions was issued at 2245 EDT:

WAUS43 KKCI 070245

WA3S

_CHIS WA 070245

AIRMET SIERRA FOR IFR AND MTN OBSCN VALID UNTIL 070900

.

AIRMET IFR...IN KY TN

FROM 20S FWA TO CVG TO HNN TO HMV TO GQO TO 40W IIU TO 20SSW IND TO 20S FWA

CIG BLW 010/VIS BLW 3SM BR. CONDS DVLPG 03-06Z. CONDS CONTG

BYD 09Z THRU 15Z.

AIRPORT INFORMATION

The intended helipad was privately owned, by the operator, and at the time of the accident did not have an operating control tower. The helipad was 40 feet by 40 feet and was located approximately 750 feet northwest of the accident site. The helipad was 895 feet above mean sea level.

WRECKAGE AND IMPACT INFORMATION

The helicopter impacted an elementary school parking lot on its right side and in a partially inverted attitude. According to surveillance video, the helicopter exploded on impact and a fireball ensued. The accident flight path was oriented on a 268 degree heading. The debris path began approximately 300 feet prior to the main wreckage and terminated approximately 90 feet past. The main rotor blades and upper deck of the helicopter came to rest approximately 300 feet prior and to the east of the impact site. The tailboom aft of the aft bulkhead and tailrotor with the gear box still attached came to rest about 300 feet to the northeast of the impact location. Both items came to rest in a tree line that ran perpendicular to the flight path and the main rotor and upper deck assembly came to rest immediately below a 3 phase power line. According to local authorities, the power line was not severed; however, a cross member located on a pole near the accident site had given way resulting in a power outage in the area. A tree, approximately 80 feet in height, located near the main rotor blade, exhibited limb damage towards the top, which was consistent with damage produced by rotor blades although due to the height it could not be confirmed. A fluid splatter, similar in appearance as an oil splatter, was located from about 100 feet prior to the wreckage up to the wreckage and was about 30 feet in width. The left side patient/crew door was located along the debris path and to the north of the path. The inside of the door exhibited hydraulic oil splatter through the entire interior.

Cockpit/Cabin Section

The cockpit/cabin section was thermally damaged and according to local authorities came to rest inverted. The engine was co-located with the cabin section. The left side instrument panel remained intact and exhibited thermal damage. The pilot's instrument panel and overhead panel were thermally damaged and did not yield any pertinent information. Examination of the pilot seat revealed extensive thermal damage; however, the seat belt mechanism was located, and was latched with the shoulder harness also secured to the latching mechanism. The anti-torque pedals were impact separated and one pedal exhibited overstress factures. Due to the extensive thermal and impact damage neither the cyclic nor collective remained attached. However, control continuity was confirmed from the aft bulkhead to the tail rotor through the tailboom fracture points. Examination of the remaining seatbelts indicated that two sets of shoulder harness latches associated with the flight nurse and paramedic seats were unsecured, The patient transport stretcher was located in the vicinity of the cockpit; however, exhibited extensive thermal damage. The seat belt latches associated with the stretcher appeared to be latched.

The landing skid assembly was located about 35 feet forward and to the left of the main wreckage as viewed from the debris path and was separated from the fuselage of the helicopter. The rear attach area exhibited some thermal damage but no other thermal damage was noted on the landing skid assembly. The right side of the skid gear, as viewed from the tail of the helicopter, had crush damage on the aft portion of the gear and was impact separated at the aft cross tube. The forward portion of the skid exhibited crush damage on the side wall of the skid tube, as well as numerous scraping and gouge marks along the tube. The right hand step was also impact separated at the forward attach point. The left hand tube and step exhibited slight inward bowing about midspan of the tube; it remained attached to the gear assembly.

Airframe

The tailboom fractured just aft of the intercostal support and forward of the horizontal stabilizer. The forward portion of the tailboom skin exhibited fracture marks consistent with compressive forces. The right side of the fuselage exhibited impact and crush damage consistent with a right side low at impact. The main and tail rotor flight controls exhibited impact and thermal damage. The fractures and position of the wreckage were consistent with an inflight breakup prior to ground impact.

Engine

The engine was co-located with the main wreckage and was found inverted. The engine remained attached through one engine mount and several steel braided hoses, the other engine mounts exhibited impact and thermal damage and were impact fractured. The compressor impeller blades rotated by hand with some resistance noted; however, several blades exhibited extensive damage to the blade tips. The upper and lower chip detectors were removed, examined, and did not display any debris. The engine was removed from the helicopter and shipped to the engine manufacturer for further examination.

Main Rotor Assembly and Transmission

The main rotor assembly and transmission (upperdeck) was located to the south side of the debris path about 300 feet prior to the main wreckage. The upperdeck came to rest at the edge of a ditch immediately below 3-phase power lines. The power lines exhibited marks similar to impact marks created by a falling object from above. The blades exhibited a braided pattern along the bottom side similar to the braided wire pattern of the 3-phase wires. Approximately 3 feet of the tip of one blade was impact separated. The fracture marks exhibited overstress signatures consistent with an overstress fracture. The mast exhibited a slight S-bend along the length. The transmission was rotated utilizing the connecting rod and continuity was confirmed through the main rotor system. The K-Flex main drive shaft was located in the parking lot approximately 75 feet from the main wreckage and exhibited rotation scoring on the engine end outer diameter consistent with contact during rotation with the forward engine firewall. No evidence was located along the leading edge of the blades that would be consistent with striking a stationary object; however, 65 inches from the center of the mast and 11.5 inches in length was faint paint transfer marks consistent with the paint color of the helicopter. Examination of the right side engine cowling exhibited a main rotor blade impact mark. Both chip detectors were removed, examined, and noted as unremarkable.

Tail Section

The tail rotor assembly remained attached to the tailboom. The tail rotor blades exhibited minimal leading edge damage and the vertical tail assembly had been impact separated from the tail boom; however, the vertical tail assembly was located in a tree in the immediate vicinity of the tail boom. Continuity was confirmed from the fracture point to the rotor blades as well as to the horizontal stabilizer. The tail rotor drive assembly shroud was removed and the assembly was examined. The drive assembly hangers aft of the fracture point exhibited aft movement and rotational scoring on the hanger assembly. The assembly hangers forward of the fracture point exhibited forward movement and rotational scoring on the hanger assembly. The tail rotor driveshaft remained connected to the end of the freewheeling unit and the splined shaft coupling was disconnected from the oil cooler. The driveshaft exhibited a fracture adjacent to the tailboom fracture. The chip detector was removed and examined and was unremarkable.

The report for the postaccident airframe examination is included in the public docket for this accident investigation.

ORGANIZATIONAL AND MANAGEMENT INFORMATION

The FAA issued Air Evac EMS, Inc., an operating certificate in February of 1986 to conduct on demand emergency medical service transports. At the time of the accident, Air Evac conducted air ambulance operations in 15 states with 114 bases. The accident crew was based at Manchester, Kentucky. The corporate headquarters, including training, the Director of Operations, Chief Pilot, and Director of Safety were located in O'Fallon, Missouri. The FAA Flight Standards Distric

NTSB Probable Cause

The pilot’s loss of helicopter control due to spatial disorientation when he inadvertently encountered night, instrument meteorological conditions, which resulted in the in-flight separation of the main rotor and tailboom.