Four Fatally Injured When Helicopter Went Down In Poor Weather

The NTSB has issued its preliminary report from a March 26th medical helicopter accident that fatally injured all four people on board the aircraft, including a patient.

According to the report, at about 0018 central daylight time, a Eurocopter AS 350 B2, N911GF, impacted trees and terrain near Enterprise, Alabama. The airline transport pilot, flight nurse, flight paramedic, and patient being transported, were fatally injured. The helicopter, registered to Haynes Life Flight LLC. and operated by Metro Aviation Inc. was substantially damaged. The flight was operated under the provisions of Title 14 Code of Federal Regulations Part 135, as a helicopter emergency medical services flight. Night instrument meteorological conditions (IMC) prevailed for the flight, which operated on a company visual flight rules (VFR) flight plan. The flight departed from a farm field near Goodman, Alabama about 0017, destined for Baptist Medical Center Heliport (AL11), Montgomery, Alabama.

According to the Coffee County Sheriff's Office, on March 25, 2016 at approximately 2309, a 911 call was received when a witness observed a motor vehicle accident on County Road 606 near Goodman, Alabama. Sheriff's deputies were dispatched along with Enterprise Rescue Squad. Deputies also contacted Haynes Life Flight dispatch, when it was discovered that the vehicle was overturned and that an unconscious victim was inside.

According to communications records, the call from the deputies was received by Haynes Life Flight Dispatch at 23:19:10. The pilot of "Life Flight 2," which was based at the Troy Regional Medical Center, Troy Alabama was notified at 23:20:38. The helicopter departed Troy at 23:26:57 and arrived at the landing zone (LZ) in a farm field adjacent to County Road 606 at 23:53:15.

According to witnesses, after touchdown, the pilot remained in the helicopter with the engine running. The flight paramedic and flight nurse exited the helicopter and entered the Enterprise Rescue Squad ambulance to help prepare the patient for transport. Once the patient was ready for transport, the flight nurse and flight paramedic along with several other emergency responders rolled the gurney approximately 70 yards through a grassy area to the helicopter and loaded the patient on-board. Once the patient had been loaded, the flight nurse and flight paramedic boarded, and at 00:16:45 the helicopter lifted off and turned north towards AL11.

Fog, mist, and reduced visibility existed at the LZ at the time of the helicopter's arrival. Witnesses also observed that these same conditions were still present when the helicopter lifted off approximately 23 minutes later. The helicopter climbed vertically into cloud layer that was approximately 150 feet above ground level and disappeared when it turned left in a northbound direction toward AL11. Review of the recorded weather at Enterprise Municipal Airport (EDN), Enterprise, Alabama, located 4 nautical miles east of the accident site, at 0015, included winds from 120 degrees at 4 knots, 3 statute miles visibility in drizzle, overcast clouds at 3oo feet, temperature 17 degrees C, dew point 17 degrees C, and an altimeter setting of 29.97 inches of mercury.

According to Haynes Life Flight, the on-board Skyconnect satellite tracking system provided position updates for the helicopter every 3 minutes. Additionally, the pilot was supposed to contact them every 15 minutes via radio. After the helicopter departed on the accident flight, Haynes Life Flight did not receive the pilot's normal 15-minute check-in, and when they checked the satellite tracking system, it showed that the helicopter was still at the LZ, though they knew it had lifted off. Haynes Life Flight then began to notify authorities that the helicopter was missing. After an extensive search by authorities, at approximately 0700, and around the area of County Road 615 and 616, search parties began to smell what they believed was jet fuel. The helicopter was eventually located the wreckage in a swampy, heavily wooded area.

Review of preliminary radar data provided by the United States Army from the approach control radar site at Cairns Army Airfield (OZR), Fort Rucker, Alabama, located 13 nautical miles east of the accident site, indicated that after takeoff the helicopter had entered a left turn, and climbed to 1,000 feet above mean sea level. At 00:18:04, the rate of turn began to increase. At 00:18:18 the rate of turn continued to increase and the helicopter reached a peak altitude of 1,100 feet. It remained at this altitude until approximately 00:18:28 when the helicopter began a rapid descent. Five seconds later, that helicopter had descended through 600 feet. Moments later, radar contact was lost when the helicopter descended below the floor of the radar coverage area.

Examination of the accident site and wreckage revealed that the helicopter had struck trees approximately a 1/2-mile north of where it had departed. A debris path that passed through the trees prior to where the helicopter came to rest and ran from south to north, exhibited an approximate 45-degree descent angle through the trees. The wreckage was heavily fragmented with only the aft fuselage being generally recognizable. The fuel tank was broken open, and the smell of jet fuel was present. The engine and transmission were separated from their mounts, and the helicopter had struck a large tree prior to coming to rest. A crater approximately 10 by 20 feet wide was present prior to a large tree the wreckage came to rest next to, and other trees (approximately 80 to 100 feet tall) along the energy path, exhibited impact damage and evidence of blade strikes.

Evidence of power was visible on the main rotor blades (MRBs) and the blue and red MRBs were broken in mutual locations. The transmission and engine were also separated from the fuselage.

The tail boom displayed a right horizontal bend mid-span but the right horizontal stabilizer and the tail rotor had remained attached to the tail boom, with both tail rotor blades exhibiting minimal damage. Control continuity and rotation were confirmed from the tailrotor to the aft bulkhead. The left side horizontal stabilizer was separated from its mounting location. The tail rotor pedals were separated from their mounting locations; however, continuity throughout the tail rotor flex ball cable was confirmed.

Continuity was also confirmed through the transmission and the top mounts of the left lateral and fore-aft main rotor hydraulic servos indicated that they had separated from the transmission due to overload forces. No abnormalities with hydraulic servo integrity were noted, and all push pull tubes and mixing units actuators were observed to be broken with overload signatures.

Examination of the engine revealed that it had separated from the helicopter during the impact sequence. Externally the engine displayed impact damage. Examination of the free turbine revealed that it had not shed its blades. The Fuel Control Unit (FCU) was separated from the accessory gearbox but both FCU shafts were present and not broken, and the FCU remained attached by the fuel and air lines. The P2 line was still attached on both the intermediate case and the FCU. The axial compressor had foreign object damage (FOD), on all 13 blades, and curling opposite the direction of rotation was observed on several. Both Module 1 and Module 5 magnetic plugs were clean. Both electric chip detectors (main and TU208 rear bearing) were clean. Module 5 was removed and the input pinion slippage mark was found displaced in the over-torqued direction approximately 2-2 1/2 mm, consistent with power at the time of main rotor strike. The freewheel shaft was checked and proper operation confirmed. Continuity to the N2 drive of the FCU was confirmed. The gas generator and free turbine could not be turned by hand. The oil, air, and fuel lines were remained connected to engine and properly saftied. The electrical connection cannon plugs were still connected to the engine deck, but the harnesses had broken during the impact sequence. The rear engine mount was still connected to the linking tube but both rubber mounts were separated from the engine deck. The front support was broken at the connection to the aircraft liaison tube. The transmission shaft was found inside the liaison tube but neither side flector groups nor bolts were connected to it. The flector group on the engine side was still connected to the flanged adapter and on the freewheel shaft. The 3 bolts to the transmission shaft had been broken and the holes were found elongated opposite the direction of rotation consistent with power being produced at rotor strike.

The accident helicopter was manufactured in 1998. It was equipped with a three-blade main rotor system, a two-blade tail rotor system, and was powered by a Turbomeca Arriel 1D1 engine rated at 641 shaft horsepower. The helicopter was equipped with skid-type landing gear, Night vision goggles (NVG) and NVG-compatible lighting, a helicopter terrain avoidance warning system, and an autopilot. The helicopter was not certificated for flight in IMC conditions.

According to the operator, the helicopter was maintained under an FAA approved aircraft inspection program. The helicopter's most recent inspection was completed on February 12, 2016. At the time of the accident, the helicopter had accrued 8,923.2 total hours of operation.

According to FAA records, the pilot held an airline transport pilot certificate with a rating for helicopter and type ratings for the AB-139 and AW-139. He also held a flight instructor certificate with ratings for helicopter and instrument helicopter. According to the operator, he had been employed by them for approximately 6 months and had 90 hours of flight experience in the accident helicopter make and model since he was hired. His total flight experience was 5,301 hours, 5,265 of which was as pilot in command, 474 hours of which was at night, and 265 of which were in actual instrument meteorological conditions. His flight experience during the 90 days prior to the accident was 47 hours, including 20 hours in the 30 days prior to the accident.
The wreckage was retained by the NTSB for further examination.

(FMI: www.ntsb.gov