N444RS

HISTORY OF FLIGHTOn August 19, 2014, about 1100 central daylight time, a McDonnell Douglas 369E, N444RS, owned and operated by Rotorworks LLC, was substantially damaged when it impacted a utility wire and terrain while maneuvering near Northport, Alabama. The commercial pilot and the passenger were fatally injured. Visual meteorological conditions prevailed, and a company flight plan was filed for the local flight, which originated from Tuscaloosa Regional Airport (TCL), Tuscaloosa, Alabama, about 1034. The aerial observation flight was conducted under the provisions of 14 Code of Federal Regulations Part 91.

According to the operator, on the morning of the accident flight, the pilot was requested to relocate the helicopter from Mobile, Alabama, to Tuscaloosa. Once in Tuscaloosa, the pilot fueled the helicopter and picked up the passenger/observer before departing on the accident flight; the purpose of which was to inspect a span of high-tension power lines for damage from a storm that had passed through the area the previous night.

About 1025, the pilot submitted a company flight plan via email, and according to satellite tracking data, departed TCL about 1034. The helicopter's location, altitude, groundspeed, and direction of travel were subsequently reported to the operator every 5 minutes, as it initially flew east, intercepted the powerline span to be inspected, and then proceeded north along the span. The helicopter's final position, as reported by the satellite tracking data, was recorded at 1100, at a GPS altitude of 457 feet, a groundspeed of 32 knots, and a track of 27 degrees true. At that time, the helicopter was positioned over the western edge of the easement through which the powerlines ran.

About 1130, the power company contacted the operator and reported an additional fault with the transmission lines the accident helicopter was tasked with inspecting, and believed that the fault may be associated with the helicopter. The operator subsequently began a search for the helicopter and provided its last known position to local law enforcement. The accident site was located by air about 1/4-mile northeast of helicopter's last reported position. PERSONNEL INFORMATIONAccording to Federal Aviation Administration (FAA) airman records, the pilot, age 51, held a commercial pilot certificate with ratings for rotorcraft-helicopter, airplane multiengine land, instrument airplane, and instrument helicopter. He also held a private pilot certificate with a rating for airplane single engine land. The pilot was issued an FAA first-class medical certificate on January 21, 2014 with no waivers or limitations. According to the operator, he had accumulated 13,500 total hours of flight experience, of which 12,860 were in rotorcraft. He had accumulated 160 total hours of experience in the 90 days preceding the accident, and overall had accumulated 1,500 hours of experience in the accident helicopter make and model. He completed his most recent flight review in February 2014. AIRCRAFT INFORMATIONAccording to FAA airworthiness records, the accident helicopter was manufactured in 1990, and was powered by a Rolls-Royce 250-C20B turboshaft engine. A review of the helicopter's maintenance records revealed that its most recent annual/100-hour inspection was completed on August 4, 2014, and at that time the helicopter had accumulated 3,765 total hours. The helicopter had accumulated 59 hours since its most recent inspection. METEOROLOGICAL INFORMATIONThe 1053 weather conditions reported at TCL, located about 18 nautical miles southwest of the accident site, included wind from 260 degrees at 5 knots, 10 statute miles visibility, a temperature of 30 degrees C, a dew point of 22 degrees C, and an altimeter setting of 29.97 inches of mercury.

At the time of the accident, the sun's angle was about 57 degrees above the horizon at an azimuth of about 122 degrees. AIRPORT INFORMATIONAccording to FAA airworthiness records, the accident helicopter was manufactured in 1990, and was powered by a Rolls-Royce 250-C20B turboshaft engine. A review of the helicopter's maintenance records revealed that its most recent annual/100-hour inspection was completed on August 4, 2014, and at that time the helicopter had accumulated 3,765 total hours. The helicopter had accumulated 59 hours since its most recent inspection. WRECKAGE AND IMPACT INFORMATIONThe accident site was located along the eastern edge of the powerline easement, which was oriented roughly north-south along uneven terrain in a shallow valley between two transmission towers. The transmission towers were identified as 81 and 82, and were located north and south of the accident site, respectively. A 6-gauge, 3-strand aluminum shield wire about 0.35 inches in diameter, which spanned between the two towers on their eastern side, was severed about 775 feet north of tower 82. The shield wire's estimated height above ground level at that point along the span was about 150 feet. The remaining fiber optic cable and three power transmission phase cables appeared undamaged.

The helicopter fuselage came to rest inverted within a creek bed, just outside and east of the easement, in a forested area. The helicopter's static mast, main rotor hub, and four of the five main rotor blades were separated from the fuselage, along with the aft portion of the tailboom. The remaining main rotor blade separated from the main rotor hub at the strap pack. The main rotor blades exhibited extensive damage which varied in severity and included fractures, gouges, bent spars, cord-wise wrinkling, leading/ trailing edge damage, bending, separation and indications of a wire strike. All of the separated components were located within about 90 feet of the fuselage, and in the general vicinity of the severed shield wire, with the aft portion of the tailboom coming to rest nearly directly below the break point of the shield wire. The wreckage displayed no evidence of a pre- or post-impact fire.

The helicopter exhibited extensive damage to the main airframe structural members, static mast support structure and center beam. The static mast was separated at the mast base by fractures near the mast base attachment points. The forward fuselage, including the door and canopy frames, cockpit, and instrument panel were also damaged. All of the canopy windscreens were broken. The cockpit compartment was compromised from ground impact. Both sides of the cockpit and cabin floors were crushed, bent and distorted. Examination of the cockpit seat belts and shoulder harnesses revealed that they functioned normally. All cockpit and cabin doors were installed, and a single set of flight controls was installed at the pilot's position in the left front seat. The pilot was wearing a helmet.

The aft boom fairing exhibited crushed, dented and torn exterior skin surfaces. The air inlet fairing was separated near its mounting base, and exhibited relatively uniform separation surfaces on both of the separated portions. The tailboom was fractured into three pieces, with the first fractured near fuselage station (FS) 200, in the area of the FS 197 mounting frame, with no apparent damage to the mounting bolts. The second section was fractured around FS 258, and exhibited concave depressions consistent in size with the main rotor profile. The third section contained the tail rotor gearbox, tail rotor assembly, vertical and horizontal stabilizers. The horizontal stabilizer and vertical stabilizers sustained various degrees of impact damage to the frame structures, leading edges and exterior skin surfaces. There was no visible indication that the shield wire made contact with the tailboom, empennage, tail rotor, or either of the helicopter's two installed wire strike protection devices.

The main transmission rotated freely, contained oil, and the chip detectors were inspected and found clean of magnetic particles. Drive continuity from the transmission to the tail rotor output pinion was present. The main rotor transmission mounting points had visible damage to the main transmission housing mounting bores and mounting studs. The main rotor transmission output splines and mating splines on the main rotor driveshaft were visibly damaged from the separation of the main rotor static mast. The engine-to-transmission drive shaft had fractured in apparent overload. The shaft fractured immediately forward of the aft flexible coupling. The coupling exhibited bending damage, but remained intact. The over-running clutch operated normally. The oil cooler blower assembly mounting bracket and scroll was impact-damaged.

The tail rotor gearbox and tail rotor assembly appeared undamaged. The gearbox was mounted securely to the FS 281 frame, contained oil, and rotated freely. There were no metallic chips on the chip detector. The tail rotor swashplate rotated smoothly. The tail rotor driveshaft fractures corresponded to the damaged tailboom. Both the forward and aft tail rotor driveshaft couplings appeared undamaged. The tail rotor blades, pitch links, hub, fork, fork bolt and elastomeric teetering bearings appeared undamaged.

There were fractures, bends and distortion throughout the flight controls. Control continuity was verified for the collective, cyclic and tail rotor controls with all control discontinuities displaying impact-related damage consistent with overload separation. The pilot's cockpit controls and under the seat routed controls were extensively damaged. The lateral and longitudinal actuators were removed and inspected. Both actuator shafts were found near the approximate mid-points of their travel. Damage and fractures to the upper controls including the control rods, pitch links, rotating and stationary swashplates displayed signatures consistent with overload separation.

The engine remained inside its cowling and all but the right forward engine mounts were fractured. The engine compressor exhibited foreign object damage consistent with in...